1989 BMW 535i HELP

[Cje34]

Good Morning Everyone!

Please forgive me if there is a thread already like this.. I just joined and I believe I scrubbed the forum clean of my issue.

i recently picked up a 89’ 535i that has been having some major stalling issues on WOT in P,N, and in gear. when gradually building throttle, it climbs to about 3-3500 RPMs before it begins to stall again. I have replaced the FPR vacuum line and the other smaller diameter one that connects to the intake. She’s throwing three codes: 1215, 1224, and 1222 when stomp tested. Used a guide from the forums to check AFM and it seems to be in spec both when cold and heated. Fresh oil change and spark plugs just put on.. injectors are sitting in my office waiting to be installed. Any ideas why this is? I found a small connector destroyed that looks to be from the engine harness (blue, yellow, white wires)… But I am not great with electronics. I’ll post the photo below in case someone knows what this plug is

Any help would be amazing! (O2 sensor is otw)

[Cje34]

Also forgot to mention I put in a new fuel pump (from ebay, with good reviews)

[shogun]

M30 engine with electronic EML fly by wire throttle valve or normal throttle valve with throttle potentiometer?
1215 Air mass/volume sensor
1224 Intake air temperature sensor
1222 Lambda Control System Bank 1: The ECM has been unable to maintain Lambda (fuel mixture or fuel trim) on Bank 1 (cylinders 1–3) of the engine.
Upload the pic of the small connector on a free pic upload and post the link here

[Cje34]

M30 engine with electronic EML fly by wire throttle valve or normal throttle valve with throttle potentiometer?
1215 Air mass/volume sensor
1224 Intake air temperature sensor
1222 Lambda Control System Bank 1: The ECM has been unable to maintain Lambda (fuel mixture or fuel trim) on Bank 1 (cylinders 1–3) of the engine.
Upload the pic of the small connector on a free pic upload and post the link here

It is a traditional throttle with a cable, no wires here! However, I should note that I have the round TPS connector that has been mentioned a few times here, which looks beat up.

here is that photo I talked about (it was not connected when I found it, haven’t tried to start again)
https://ibb.co/02bWJVC

[Cactuar]

That's the connector to the oil level sensor (next to it is the connector to the O2 sensor). Even if you had it disconnected it wouldn't prevent the engine from starting or running well I believe.

[Cje34]

Ahhh okay, I wasn’t sure, Thanks for your help! After some research I’m beginning to think my throttle position switch might be the cause of the stall past 3k or on WOT. It’s like hitting a brick wall when reving (engine dies as soon as throttle goes past ~10%.

[shogun]

BMW Throttle Position Sensor Testing, just as example on an E34 733 M30 https://www.youtube.com/watch?v=7-_ORQ-Gsmg
quote: Procedure:
-first step is the ensure the throttle position sensor is step up correctly
-with the throttle plate fully closed, open the throttle very slightly and you should be able to hear an audible "click"
-if not the sensor is either broken or not adjusted correctly
-with the throttle plate fully closed, loosen the two phillips screws and rotate the sensor all the way clockwise until you feel it stop
-do not go too far so it opens up the throttle plate
-tighten down the screws
-now retest to see if it has an audible "click", if not the switch is broken
-now testing with the multimeter, remove the wiring harness plug
-on the side of the throttle position sensor, there will be numbers
-3 (wide open throttle), 18 (input single), 2 (idle)
-using the multimeter on the ohms setting, we will be testing each plug to ensure it is working correctly
-with the throttle close, there should be continuity between pinouts 2 and 18, and an open circuit between pinouts 3 and 18
-with the throttle increased slightly, there should be an open circuit between pinouts 2 and 18, and an open circuit between pinouts 3 and 18
-with the throttle fully opened, there should be an open circuit between pinouts 2 and 18, and continuity between pinouts 3 and 18
-if the test fails, the sensor does need to be replaced
-the sensor can be opened up, although it is somewhat difficult
-using a razor knife, cut around the seam to break the glue
-then using a small standard screwdriver, slowly pry away the case
-once open, you can spray the microswitch with contact cleaner or clean the wide open throttle contacts (this is a temporary fix, I would recommend buying a new replacement sensor)
Symptoms of a Bad Throttle Position Sensor https://www.bimmerforums.com/forum/s...osition-Sensor
https://www.bimmerforums.com/forum/s...technical-data
https://www.hella.com/techworld/au/T...tiometer-3742/

[Cje34]

Going to try this test asap today. Shogun, do you know if it’s possible to convert from the round plug to the square/rectangle that other cars seem to have?

[viperocco]

What about your fuel filter?

[moroza]

What diagnostics have you done? Read spark plugs? Checked fuel pressure? Smoke test?

[shogun]

Shogun, do you know if it’s possible to convert from the round plug to the square/rectangle that other cars seem to have?

Which plug? Diagnosis port? What-data-can-be-read-off-the-e34-diag-port https://www.bimmerforums.com/forum/s...-e34-diag-port

[moroza]

Is the "rectangular plug" you mean this one?


If so, that's a standard OBD2 port, and while it's certainly possible to retrofit one into an E34 (in fact, it's been done by a forum member who hasn't been on in some time and whose username I forget. Mike something, I think. Has an E30 pickup truck among other cool shit.), in practical terms it's not an option in this instance nor would it help much.

[Cje34]

Sorry, no! I meant the Throttle Position Sensor (switch?). My car has the fabled ROUND 6 pin connector, while many other cars with the m30 happen to have the rectangle sensor connector. I was wondering if anyone had converted it before.

- - - Updated - - -

Here’s the checklist so far:

Checked MAF for ohm readings, it seems to be good.
new spark plugs
cleaned rotor and cap contacts
New fuel pump (made sure it has clean gas too)
New fuel filter
Changed vacuum hoses that connect FPR, PCV, and brake booster
Checked all fuses + fuel relay
*Tried diagnosing o2 sensor by unplugging (ran horrible)*

what am I missing? If I press the gas she dies and 50% of the time catches idle again, or dies.

- - - Updated - - -

What about your fuel filter?

Changed this with new fuel and pump, I also thought it would be this :/

[viperocco]

I see you indicated that you tested the MAF; have you tried disconnecting it to see what happens?