E32 735 hard starting, bad cylinder identification sensor?

[Annddrriy]

Could bad cylinder identification sensor cause hard starting and a spark plug to misfire during wet weather poor fuel economy rough idle hesitation when accelerating and increased hydrocarbon HC emissions ? Thanks in advance for your answer !

[Annddrriy]

When I start the engine by cranking starter it usually takes over cranking. Instead to start the engine in 1.5 seconds but it takes 3 seconds. I suspect that the cylinder identification sensor is not working. For me it is very difficult to check even with the oscilloscope if is cylinder identification sensor working correctly. To check cylinder identification sensor I am using two channels oscilloscope by connecting channel one to injector bank 1 and second channel connecting to the injector bank 2 and when pattern appears on the oscilloscope screen then one injector bank fires the pattern of another injector bank piles on top of the injector bank and seems to be the injector banks fires in batch mode ? It so short time in milliseconds between injector banks. To troubleshoot cylinder identification sensor if is working correctly then it is one way only to check if the injector banks fires sequentially that when pattern begins show up on the screen it should be one injector bank fire pattern in front of another that is mean the injector banks fires sequentially and then they pile on each other while oscilloscope recording continue. Same thing when oscilloscope recording stop then on the end of the last injector bank fire should be one bank in front of another on the end of the oscilloscope screen that is mean the injector banks fires sequentially. If the injector banks fires in batch that when pattern begins show up on the screen it should be both injector bank fire pattern piles on each other.
It sounds like I’m dealing with an extended crank time issue and suspect the cylinder identification sensor also known as a camshaft position sensor or a similar sensor depending on the engine may not be functioning properly. I’m trying to verify whether the injectors are firing sequentially or in batch mode using a dual channel oscilloscope which is a solid approach.
Here’s a breakdown of what might help in troubleshooting the cylinder identification sensor more effectively:
Understanding Sequential and Batch Fire:
Sequential injection means each injector bank fires individually in sync with its respective cylinder’s intake stroke. You should see the injectors bank firing one after the other on your oscilloscope with one pattern leading slightly ahead of the other.
Batch injection means multiple injectors in this case both banks fire at the same time and on the oscilloscope the patterns from both banks would overlap.
Oscilloscope Setup:
Channel 1 (Bank 1) and Channel 2 (Bank 2):
My setup with each oscilloscope channel connected to one bank of injectors is correct. What I want to see is whether the patterns on the scope show a distinct separation between the injector pulses of the two banks sequential or if the pulses overlap batch.
I mentioned that the patterns appear close together in milliseconds this might be normal depending on the engine RPM but if they’re truly overlapping that could indicate batch firing.
Key Troubleshooting Points:
If the cylinder identification sensor is not working the engine might default to a batch fire mode as the engine control module ECM doesn’t know the exact cylinder number 6 position.
Checked for any diagnostic trouble codes DTC stored in the engine ECM. A faulty cylinder identification sensor should trigger a code which could help in identifying the issue more easily. The only one code appears 1444 which means no fault code as written in service manual.
If it’s difficult to see distinct injector firing patterns on the oscilloscope I try slowing down the engine RPM or use a trigger feature on my scope to stabilize the patterns. This will help in visualizing whether one bank fires slightly before the other or if they fire simultaneously.
Injector and Sensor Timing:
If I’m seeing injector pulses that pile on top of each other the injector banks may indeed be firing in batch mode. To further confirm I try comparing the oscilloscope readings while manipulating the sensor input if possible. I can also check the sensor’s signal directly on the scope by probing it which might give me a clearer idea if it’s outputting a reliable signal.
If the oscilloscope shows that the injectors fire in batch mode and no error codes are present replacing or further testing the cylinder identification sensor may be my next step.

[shogun]

A bad cylinder identification sensor (CIS) might cause hard starting from my experience with M70. Maybe just change to another CIS and test again, I do not have equipment like you with oscilloscope.
A spark plug to misfire during wet weather is probably not related to the CIS, maybe moisture somewhere in the ignition system?

[Annddrriy]

Does ignition timing a bit off if cylinder identification sensor is not working. In the case of the BMW M30/M70 engines found in the E32 735i and 735iL and 750i and 750iL the cylinder identification CID sensor also known as the camshaft position sensor plays a crucial role in determining the correct timing for fuel injection and ignition.
If the CID sensor in the M70M30 engines is not functioning properly it can indeed cause the ignition timing to be off. The ECU relies on this sensor to identify which cylinder is in the compression stroke for precise timing. Without the CID sensor the engine may not be able to optimize the timing correctly leading to symptoms such as rough idling misfires poor fuel economy and reduced performance.
In some cases the engine ECU might switch to a fallback mode like batch firing the injectors but the overall timing and engine performance would still be suboptimal.
if the cylinder identification CID sensor is not working it can affect the ignition timing. The CID sensor helps the engine control unit ECU identify which cylinder is in the power stroke allowing for accurate fuel injection and ignition timing. If the sensor is malfunctioning the engine ECU may struggle to determine the correct timing for each cylinder leading to improper ignition timing misfires reduced performance or even engine stalling.
The severity of the timing issue depends on the engine’s design. Some engines may default to a limp mode
to keep the vehicle running but with reduced efficiency and power.
If you’re experiencing issues with the ignition timing on an M30M70 engines checking the CID sensor’s functionality would be an important diagnostic step.

[Annddrriy]

At the engine speed RPM750 It takes 160 milliseconds which is 720 degrees to fire all six cylinders in the firing order 1-5-3-6-2-4 but first injector bank fires then after another injector bank fires since all cylinders fire once every 2 revolutions. That is mean that cylinder identification sensor or spark plug lead sensor send a signal to the engine ECU every 160 milliseconds ?


Yes, exactly ! The cylinder identification sensor or spark plug lead sensor sends a signal to the engine ECU every 160 milliseconds at 750 RPM because cylinder number 6 fires once every 720 degrees (which is two crankshaft revolutions. This corresponds to 160 milliseconds between each signal at idle speed.


Since the M30B35 engine operates on a 4-stroke cycle every cylinder and its corresponding injector fires once every 720 degrees of crankshaft rotation. The two injector banks alternate firing within that 720 degrees but the cylinder identification sensor sends its signal specifically when cylinder number 6 fires.


If one injector bank fires then in how many milliseconds next injector bank fires ?
If one injector bank fires and it takes 160 milliseconds for the crankshaft to complete 720 degrees which corresponds to the firing of all six cylinders the two injector banks will alternate firing.
Assuming each bank fires once during that 160 milliseconds here’s how it works:
Time for one bank to fire:
160 milliseconds to complete one full cycle both banks firing.
Time until the next bank fires:
Since the banks alternate if one bank fires the next bank will fire after half of that time.
Therefore it would take 80 milliseconds for the next injector bank to fire after the first bank fires.
In summary:
First injector bank fires: 0 milliseconds
Second injector bank fires: 80 milliseconds later
How many times each injector banks fires in 1 second ?
To calculate how many times each injector bank fires in one second at an engine speed of 750 RPM follow these steps:
Revolutions per Minute RPM: 750 RPM.
Revolutions per Second RPS:
750 RPM ÷ 60 seconds = 12.5 revolutions per second.
Firing every two revolutions: Since each bank of injectors fires once every 720 degrees or two revolutions they will fire alternately in that time.
In one second:
Total cycles injector firings in two revolutions: 12.5 revolutions per second × 2 = 25 cycles per second.
Since there are two banks:
Each injector bank fires once per cycle.
Therefore, each bank fires 12.5 times per second.
In summary:
Each injector bank fires 12.5 times per second at an engine speed of 750 RPM.
Does one injector bank fires ones at 360 degrees which is one engine revolution ?
Yes in a six cylinder engine like the M30B35 one injector bank fires once at 360 degrees which is equivalent to one engine revolution.
Here’s how it works:
One Injector Bank Fires:
During the first 360 degrees one complete revolution one of the injector banks fires Bank 1.
Second Bank Fires:
During the next 360 degrees the second revolution the other injector bank fires Bank 2.


So each injector bank alternates firing once every 360 degrees. This means that:
Bank 1 fires at 0° first revolution.
Bank 2 fires at 360° second revolution.
This firing sequence continues with each bank firing every 720 degrees two revolutions but alternating every 360 degrees.
How many milliseconds it takes to fire one injector bank ?
To calculate how many milliseconds it takes to fire one injector bank at an engine speed of 750 RPM we can use the following steps:
Determine the time for one complete cycle 720 degrees:
At 750 RPM we previously calculated that it takes 160 milliseconds for the crankshaft to complete 720 degrees two revolutions.
Determine the timing for each injector bank:
Since there are two injector banks and they alternate firing each bank will fire once in that 160 milliseconds.
Timing Calculation
Total time for both banks to fire 720 degrees: 160 milliseconds.
Time between each bank firing: Each bank fires every 80 milliseconds:
First bank fires: 0 milliseconds.
Second bank fires: 80 milliseconds later.
Injector Bank Firing Duration
The duration for which each injector remains open injector pulse width typically ranges from 2 to 10 milliseconds during normal operation depending on engine demand and conditions.
Summary
Each injector bank fires once every 160 milliseconds.
The pulse duration how long the injector stays open can vary but is typically 2 to 10 milliseconds.

[Annddrriy]

What is going on in the engine performance when cylinder identification sensor is not working correctly ?
Both injector banks fire simultaneously every 80 milliseconds 360 degrees at 750 RPM because cylinder identification sensor is not working. Is that correct ? Yes. That’s correct. If the cylinder identification sensor is not working the engine control unit ECU will switch to batch fire mode where both injector banks fire simultaneously every 360 degrees of crankshaft rotation once per engine revolution. If cylinder identification sensor works then the engine ECU will switch to sequential fire. One injector bank fire every 360 degrees of crankshaft rotation.


At 750 RPM:
Each revolution of the crankshaft takes 80 milliseconds since 750 RPM means the crankshaft rotates 12.5 times per second or one revolution every 80 milliseconds.
Therefore in batch fire mode both injector banks will fire every 80 milliseconds because the engine ECU is no longer able to determine which bank to fire sequentially due to the faulty cylinder identification sensor.
So the injectors will fire once per engine revolution 360 degrees or every 80 milliseconds at 750 RPM which means both banks are fired together during each cycle.
If the cylinder identification sensor is not working the engine control unit ECU will switch to batch fire mode where both injector banks fire simultaneously every 360 degrees of crankshaft rotation once per engine revolution.
What is time in milliseconds when injector bank fire next time ? For an example every 360 degrees both injector banks fire then off for few milliseconds and then fire again ?
To calculate the time in milliseconds when the injector banks fire next let’s break it down:


Key points:
When the cylinder identification sensor is not working the engine control unit ECU switches to batch fire mode.
In batch fire mode both injector banks fire simultaneously every 360 degrees of crankshaft rotation which is once per engine revolution.


At 750 RPM:
750 RPM means the engine completes 750 revolutions per minute.
In terms of time per revolution it takes:
So the both injector banks fire every 80 milliseconds in batch mode as one engine revolution takes 80 milliseconds at 750 RPM.


Firing and Off Time Cycle:
One injector bank will fire at the start of every 360 degrees of crankshaft rotation once per revolution of CIS is not working then two injector banks will fire at start of every 360 degrees of crankshaft rotation..
After firing there is an off period until the next 360 degrees next engine revolution.
For an example the both injector banks are on for a certain duration and then off for the remaining portion of the 80 milliseconds.


For an injector pulse duration:
The injector pulse width how long the injector is on depends on the engine’s load and fuel requirements but let’s assume the pulse width on time is 5 milliseconds for idle because CIS not working and injection fall into limited operating strategy. If CIS is working correctly then the pulse width decreases when the engine speed increases.


Timing Example:
Both banks fire at time t = 0 milliseconds start of the revolution.
Both injector banks remain on for 5 milliseconds pulse width.
Both injector banks are then off for the remaining 80 milliseconds.
Both injector banks fire again at t = 80 milliseconds next revolution after 360 degrees of crankshaft rotation.


Summary:


At 750 RPM in batch fire mode:
Both injector banks fire every 80 milliseconds once per revolution and 5 milliseconds is pulse width.
For an example if the pulse width is 5 milliseconds the both injector banks are on for 5 milliseconds then off for the remaining 80 milliseconds before firing again at the next 80 millisecond mark next engine revolution.
Both injector banks are on for a certain duration in 360 degrees which takes 80 milliseconds and then off for the remaining portion of the 80 milliseconds which is duration 360 degrees ? Is that correct ?
Yes. That’s correct. Let’s clarify the process further:
At 750 RPM one complete revolution of the crankshaft 360 degrees takes 80 milliseconds.
In batch fire mode when the cylinder identification sensor is not working both injector banks fire simultaneously every 360 degrees once per engine revolution.


Timing Breakdown:
Injectors on firing:
The injectors will be on for a certain portion of the 80 milliseconds. This period is known as the injector pulse width which depends on engine load and fuel requirements. For an example if the pulse width is 5 milliseconds the injectors will spray fuel for the first 5 milliseconds of that 80 millisecond cycle.
Injectors off:
After the injectors fire for the pulse width duration 5 milliseconds they will be off for the remaining time. In this case they would be off for the next 80 milliseconds 80 milliseconds total minus 5 milliseconds of firing pulse width.


Summary:
The 360 degree crankshaft revolution takes 80 milliseconds.
The injectors are on for the duration of the pulse width 5 milliseconds.
The injectors are off for the remaining time in that revolution 80 milliseconds if the pulse width is 5 milliseconds.
Both banks fire again when the next 360 degree revolution begins every 80 milliseconds.

[Annddrriy]

1. The automatic transmission TCM Injection Open Time connected to the engine ECU Fuel Rate Input.

Injection open time is indeed connected to the fuel rate input in the context of engine management systems such as in the BMW E32 M30B35/M60B30B40/M70B50 Here’s how these two components interact:
Injection Open Time:
This refers to the duration for which the fuel injectors are open during each injection cycle. A longer injection open time allows more fuel to be delivered to the engine while a shorter duration restricts the amount of fuel.
Fuel Rate Input:
The fuel rate input provides the engine control module ECM with data regarding the amount of fuel being consumed or the desired fuel delivery based on various factors like engine load speed and throttle position.
Interaction:
The engine ECM uses the information from the fuel rate input to determine how long to keep the fuel injectors open. If the demand for power increases like during acceleration the engine ECM will increase the injection open time to supply more fuel. Conversely if the engine is under less load it may decrease the open time to maintain optimal fuel efficiency.
Performance Optimisation:
By adjusting the injection open time based on the fuel rate input the engine ECM can optimise engine performance fuel efficiency and emissions. This feedback loop ensures that the engine gets the right amount of fuel for the current operating conditions.
Here’s more specific questions about how this works in BMW E32 ?
Injection Open Time under LOS limited operating strategy of failure cylinder identification sensor. This refers to the duration for which the fuel injectors are open during each injection cycle longer injection open time allows more fuel to be delivered to the engine while a shorter duration restricts the amount of fuel but if the engine ECU switch to the default mode such as LOS limited operating strategy then the fuel injectors no more longer and no more shorter duration restricts because the engine ECU is using default preprogrammed map which has no any adjustment to the injectors duration restriction.
When the Engine Control Unit ECU of a BMW E32 M30M60M70 switches to a Limited Operating Strategy LOS due to the failure of critical sensors such as the cylinder identification sensor or camshaft sensor in M60 engine the engine ECU indeed defaults to preprogrammed values. Here’s how it works in more detail:
LOS Limited Operating Strategy: When a key sensor like the cylinder identification sensor fails the engine ECU can no longer accurately determine which cylinder is on its compression stroke. As a result the engine ECU switch to a fail safe mode often referred to as the LOS limited operating strategy to keep the engine running but with limited performance.
Preprogrammed Fuel Maps:
In LOS limited operating strategy the engine ECU relies on preprogrammed default maps for fuel delivery ignition timing and other parameters. These maps are conservative settings designed to allow the engine to run in a safe but less efficient manner. The engine ECU no longer dynamically adjusts the injection open time based on real time sensor inputs.
Injection Open Time in LOS limited operating strategy: In this default mode the injection open time will be fixed according to the default map. This means:
No longer based on precise feedback from the cylinder identification sensor or camshaft sensor or other real time data like engine load or throttle position.
The fuel delivery will be less optimised resulting in potential inefficiencies such as poorer fuel economy or reduced power output.
No Fine Tuned Adjustments:
As it mentioned the engine ECU cannot extend or reduce the injection duration dynamically in LOS limited operating strategy. The injectors will fire based on preset values that are designed to keep the engine operational but they won’t be as finely tuned as they would be under normal operation with all sensors functioning properly.
So in LOS limited operating strategy mode the fuel injectors will no longer adjust their open time dynamically. Instead the engine ECU will use default settings that limit optimisation for performance or fuel efficiency. This is essentially a safety measure to allow the engine to continue running until repairs can be made.

[Annddrriy]

How the engine is running lean or rich when the engine ECU fallback in the LOS limited operating strategy ?
When the Engine Control Unit ECU of the BMW E32 M30B35M60/B30B40M70B50 engines falls back into the Limited Operating Strategy LOS due to sensor failure such as a cylinder identification sensor or camshaft sensor failure the engine run lean or rich depending on how the preprogrammed fallback maps are set. This is because in LOS limited operating strategy the engine ECU can no longer rely on real time data from critical sensors to adjust the air fuel mixture accurately. Here’s how the engine run lean or rich in LOS limited operating strategy:


Fallback to Default Maps:


In LOS limited operating strategy the engine ECU uses preprogrammed default fuel and ignition maps that are designed to keep the engine running but without the fine adjustments it normally makes based on sensor inputs like oxygen sensors mass airflow sensors and throttle position sensors. These maps are conservative and often designed to protect the engine under various conditions.


Rich Running Condition:


The engine run rich more fuel than needed in the mixture in LOS limited operating strategy because:
The default map might be set to supply extra fuel as a safeguard. This helps protect the engine from running too lean which could lead to overheating or knocking.
Without precise feedback from sensors especially the oxygen sensor the engine ECU error on the side of providing more fuel to ensure combustion stability.
Running rich might result in higher fuel consumption black exhaust smoke and possibly fouled spark plugs.


Lean Running Condition:


The engine run lean less fuel than needed in LOS limited operating strategy because:
The engine ECU is using a pre set fuel map that assumes a certain amount of airflow throttle position and engine load which may not reflect actual conditions. If the engine requires more fuel than the map provides it will run lean.
Running lean means the engine is receiving more air compared to fuel which can lead to increased combustion temperatures potential knocking or pre ignition and overall poor performance.
In LOS limited operating strategy the lack of feedback from the mass air flow MAF sensor or oxygen sensors can cause incorrect fuel delivery.


No Real Time Adjustments:


Normally the engine ECU relies on feedback from the oxygen sensors pre and post catalytic converter to maintain an optimal air fuel ratio by adjusting the fuel injector open time. In LOS limited operating strategy the engine ECU no longer gets accurate feedback meaning it operates with fixed values which can result in running either too rich or too lean.


Impact on Injection Open Time:


The injection open time is no longer dynamically adjusted in LOS limited operating strategy. The injectors will follow the pre programmed default values which may not be ideal for the current operating conditions leading to either too much fuel rich or too little fuel lean.


Summary:


In LOS limited operating strategy the engine is likely to run either lean or rich depending on the default maps loaded into the engine ECU for safety and engine protection. Since the engine ECU can no longer adjust fuel delivery based on real time sensor data fuel delivery is not optimised leading to one of these conditions. Running rich is more common as a safety strategy but lean conditions can also occur depending on how the fallback map is structured.
If the engine enters LOS limited operating strategy it’s important to diagnose and repair the faulty sensor as soon as possible to restore normal operation and prevent potential engine damage.

[Annddrriy]

Do you mean this conical lip should be facing to the rotor cap ?
What if original sensor doesn’t have conical lip and some of the others cylinder identification sensors don’t have conical lip.

[shogun]

yes, the hole inside is conical and you see the small parts where your arrow points. That is the way at least on my M70. If no small part on aftermarket donut, check the installation instructions the part comes with, and for marks on the donut for directions/how to install on your M30.
https://www.e30zone.net/e30wiki/index.php/CID
https://www.bimmerforums.com/forum/s...gnition-pickup
https://www.msextra.com/forums/viewtopic.php?t=72986

[Annddrriy]

I hope original BMW cylinder identification sensor will come with parts where the arrow points then it will be easy to install.

[Annddrriy]

Do you have any idea why cylinder identification sensor is not fit for the vehicle with E32 735i/iL3430 ccm 162 KW 220 PS and the vehicle with E32 735i/iL
3430 ccm 155 KW 211 PS the cylinder identification sensor fits to the 155KW/211PS ? Thanks in advance for your answer ?
IMG_0931.jpegIMG_0930.jpeg

[shogun]

I do not know the source of your pics? Based on bmwfan parts catalog, both have the same number, use with your VIN http://bmwfans.info/parts-catalog
1988 EURO 735i has 12121722571 CIS, 1989 EURO 735i has 12121722571 CIS

[Annddrriy]

The source of my pictures was EBay. The difference between two engines just 9 PS and 7 KW. I assume this vehicle E32 735i/iL 3430 ccm 162 KW 220 PS has a bit more KV at the secondary ignition spark plug wire then requires another pulse generator to function properly.

[shogun]

I assume the ebay website pics statements are not correct, both show the same part number pulse generator 12121722571, same # is used. I extra checked for you
EURO model 735 12121722571 Production from Apr '88 - now , Old p/n 12121722588 , Bilaterally exchangeable, Production Sep '86 - Sep '88
USA model 735 same
Japan model 735 same
South Africa model 735 same
same numbers used on E34 530/535 M30B30, M30B35, E24 635CSi M30, E32 730 M30B30, 735 M30B35

[Annddrriy]

Thank you !

[Annddrriy]

Does each group of injectors fires once every two engine revolutions or every one engine revolutions in the BMW E32 M30B30B35 engines with the Bosch Motronic 1.1/1.3 system ? Thanks in advance for your answer !

[shogun]

TheMotronic1.1 & 1.3 multi-point injection system pulses the injectors semi-sequentially and once every two engine revolutions.During engine start-up below 600rpm the ECU pulses all injectors simultaneously. Once 600 rpm has been attained and if the ECU has received a signal from the CID sensor, each injector bank will be pulsed alternatively according to which pair of cylinders are approaching TDC. If a signal is not received from the CID sensor the injectors will remain on simultaneous operation. However, if the CID sensor subsequently sends a signal to the ECU after the engine has commenced running, the ECU will pulse the injectors semi-sequentially after the next deceleration phase -even if the CID sensor then ceases to send a signal. During start-up from cold, injector pulse duration is increased to provide a richer air/fuel mixture and pulse frequency is also increased. In addition, the ignition timing is also retarded. Injector frequency & pulse duration and degree of timing retard depend upon the engine temperature both during start-up and immediately afterwards. If the engine is restarted within one minute of the first start occurance, less overall fuel is injected to reduce the risk of fuel flooding into the engine. https://www.opel-scanner.com/files/DME_1.1_1.3.pdf

[Annddrriy]

Thank you for the reply ! I assume the ignition spark timing and injection fuel timing are both controlled by separate microcontrollers. If for an example the injection fuel timing microcontroller can not handle the process of failure cylinder identification sensor then ignition spark timing microcontroller will take the appropriate control for both the ignition spark timing and injection fuel timing as the system known limited operating strategy LOS.

[shogun]

to test the CIS the E32 workshop manual mentions for M30 and M70: Resistance at 3-pin connector. Measure plug between pin 1 + 2, ≤1 ohm, insulation resistance between pin 2 + 3: ≥ 10 MOhm, same in E31 workshop manual, see page 12-14/1 checking sender for cylinder identification for M70, S70 https://e31repair.com/

Then we discussed about the direction of the CIS, I am not 100% sure if the direction makes the difference and/or other factors, like too thick insulation of the ignition wire, or maybe other factors. I have the feeling if the direction is the most important for functioning, then it would be clearly mentioned in the workshop manual. On the other hand electr. engineers from the E31 forum mentioned "I suspect you'll see a ring wave; I'm also convinced there is a proper polarity to them.. if connected backwards, the first 'ring' will be negative, and the positive cycle might not be enough magnitude to trigger the DME. "
also here nothing special mentioned: https://web.archive.org/web/20170424...tot/TI05_e.pdf
Page 11 shows pics + instructions / tips when installing in BMW with pulse timer/cylinder identification sensor/donut for the 4 or 6 cylinder versions. On 4 cylinder engines an induction timer is fitted to the ignition cable of the 4th cylinder, on 6 cylinder engines this is fitted to the ignition cable of the 6th cylinder. When replacing cables, save the time-consuming and costly work of refitting an ignition cable with a built-in pulse timer. Just remove the defective cable only.Unscrew the ignition distributor plug on the new Copper Cable (spray with Beru installation oil).Drill 8 mm hole on the pulse timer (turn drill by hand). The ignition cable with the M3 connection can now be pushed through the pulse timer. Now lubricate the ignition cable with installation oil. Finally, screw on the ignition distributor connector of the Copper Cable.

If you have an oscilloscope , test with that and you know for sure it works or not.

[shogun]

post your E32 problems in the E32 forum, moved from E30 forum to this thread

[Annddrriy]

Ok no problem ! Thank you for the reply ! I would like to discuss with you if you don’t mind about wiring issues for fuel pump and the engine speed output and the automatic transmission engine speed signal.
Fuel pump wiring issues.
I would like to discuss with you about BMW E32 with EML and BMW E32 without EML. The BMW E32 M30B35 which is with EML means electronic throttle control throttle drive by wire and the BMW E32 M30B35 which is without EML means throttle plate drive by steel wire. The BMW E32 M30B35 which is with EML the automatic transmission TCM pin 21 which is engine speed signal connected to the engine ECU pin 6 which is engine speed output and in BMW E32 M30B35 which is without EML the automatic transmission TCM pin 21 which is engine speed signal connected to the fuel pump positive supply terminal but not connected to the engine ECU pin 6 which is engine speed output. Here’s the question where is connected correct in BMW E32 M30B35 with EML or in BMW E32 M30B35 without EML ? Is one of the BMW E32 M30B35 has wiring problem which is not connected right ?
The difference I am describing between the two BMW E32 M30B35 configurations with and without EML involves how the engine speed signal RPM signal is routed from the automatic transmission control module TCM to either the engine ECU and the fuel pump circuit.


BMW E32 M30B35 with EML Electronic Throttle Control Drive by Wire
Pin 21 of the automatic transmission TCM is connected to pin 6 of the engine ECUwhich is the engine speed signal output. This setup allows the engine ECU to monitor engine speed and it makes sense for the EML equipped model since the engine ECU needs to closely manage throttle control engine performance and transmission behaviour based on precise engine speed data.


BMW E32 M30B35 without EML Throttle Plate Controlled manually by Steel Wire


In this case I am describing pin 21 of the automatic transmission TCM being connected to the fuel pump positive supply terminal and not connected to pin 6 of the engine ECU which is the engine speed output. This setup seems unusual. Normally the engine speed signal should go to the engine ECU for proper engine management and communication with the automatic transmission. If the TCM pin 21 which is the engine speed signal is not connected to the engine ECU pin 6 then the engine ECU might not have the necessary data to manage engine performance and communicate with the TCM effectively. What do you think about from your experience ? How the wiring should be connected correctly ? Thanks in advance for your answer !


Analysis and Conclusion
The BMW E32 M30B35 with EML the automatic transmission TCM pin 21 is connected to pin 6 of the engine ECU appears to be the correct wiring. The engine speed signal is appropriately routed to the engine ECU which is crucial for the engine ECU to manage throttle fuel injection and transmission behaviour.
The BMW E32 M30B35 without EML might have a wiring issue. Connecting the engine speed signal from the TCM pin 21 to the fuel pump circuit instead of the engine ECU pin 6 which is the engine speed output it could disrupt communication between the engine management system and the automatic transmission. This connection should likely be routed to pin 6 of the engine ECU even vehicles without EML to ensure proper engine speed feedback for the system.
It seems the BMW without EML may have an incorrect or incomplete wiring setup. You may want to re route the engine speed signal to the ECU pin 6 to ensure correct functionality.

[Annddrriy]

I would like to discuss with you about wiring issue because you have clue what is going on with wiring in BMW E32 models and there is no sense to install brand new original BMW cylinder identification sensor if is wiring has issue between the automatic transmission TCM and the engine ECU if the cylinder identification sensor will be installed but wiring has issue it could block the sensor functionality. Is it make sense ? Same thing like when you upgrade the engine ECU chip for better performance but if the vehicle has the injection issue then upgraded chip will not work. Thank you in advance for your answer !

[Annddrriy]

Before making this modification it’s important to verify whether the TCM can handle a square wave signal from the engine ECU pin 6 instead of an analog wave signal from the fuel pump relay If the TCM is only designed to work with analog signals this modification could cause more issues especially with transmission performance. Is this possible ? Thanks in advance for your answer ?

[Annddrriy]

In the BMW E32 M30B35 without EML the automatic transmission TCM pin 21 engine speed signal expects an analog wave signal from the engine ECU pin 3 which also controls the fuel pump relay. This signal is used by the automatic transmission TCM to determine engine speed for transmission operations.
The ECU pin 6 on the other hand provides a square wave signal designed for the instrument cluster to display engine RPM. However this square wave is not sent to the TCM in vehicles without EML as the TCM relies on the analog signal from pin 3 for engine speed data.
If you were to connect the square wave signal from ECU pin 6 to TCM pin 21 it might not function correctly because the TCM is likely designed to interpret the analog signal not the square wave signal.