My e30 was idling pretty rough and was blowing some black exhaust So I just replaced the fuel injectors and a couple fuel hoses and afterwards after getting all the hoses and wires reconnected the engine did turn over and it ran for a bit even seem to run good for a little... no more black exhaust either, but then seemed to idle rough again and then just died. Now it wont even turn over. Starter sounds great and it does try to start... plenty of power to the starter but she just doesnt want to start. Not sure whats up. Fully checked all hoses, all wires... and fuses. Everything seems to be in place and tightened good. I dont get it. Why wont this car turn over now??
I also replaced the idle control module since i had the rough idling issue. So that was replaced too. Also a new battery. I cant figure out why the car wont turn over at all now when trying to start. You can tell it sounds like it WANTS to start but just not quite getting there.
Any help or ideas here would be greatly appreciated!
You mentioned fuel hoses but when was the fuel filter replaced? That’s important for fuel delivery. If you have good cranking and good spark, the fuel might be your issue.
After that you want to start looking at the air intake side to make sure everything is good there.
Good luck
dj Roo
‘87 325is, ‘06 Z4
So I forgot to mention I also add replaced the fuel filter as well. And yes as mentioned checked all hoses and lines and doesnt seem to have any vacuum leaks.
How do I tell if my distributor cap is not workin? Or what if its my spark plug wires? Possible for one of them to be bad?
Last edited by concort; 03-12-2022 at 09:48 PM.
How did you check the intake side? A smoke test is the best way to identify any vacuum leaks that could cause idle issues. Something to check but if you had black smoke while running that usually means it was running rich.
A rich condition could be from too much fuel (bad fuel pressure regulator or incorrect injection cycle) or the engine isn’t burning all the fuel (spark plugs or distributor)
If it’s a distributor or spark issue, your distributor points could be worn out, wires going bad, wire connections corroded, or spark plugs worn out. All things I would be checking on the spark side.
dj Roo
‘87 325is, ‘06 Z4
Have you checked fuel pressure?
So the plugs were replaced about two years ago and the wires look fairly new... within 5 years or sooner. I did check power at the coil with a milti-meter while cranking the starter and nothing was registering...hmmm. I wonder if my coil is bad. Any other way to test the coil to be sure?
I just replaced the fuel pump and it wasnt that. Engine still wont turn over. I tested via jump wire from the relay in the engine compartment and the pump works... I think its gotta be CPS...? What else could it be? Oh and I tested for spark at spark plugs and im getting a spark there.
check the reading on the crank sensor with your multimeter. i cannot remember off the top of my head what it should be but i am sure google will tell you. i had one go bad once that if i wiggled the wire to the crank sensor, the car would act up. so you might want to pull it off and look for broken wires at the sensor head if google doesn't tell you what it should read
No e30s again.
The engine cranks and you have spark...correct? I would start with a compression test, you can probably borrow a kit from a local auto parts store. Also, check the fuel pressure, again you should be able to borrow a kit from the auto parts store.
How old is the timing belt? Maybe jumped a tooth or two? You could check by removing the front cover and see if the timing marks align.
Do you have one or two position sensors? With my 85E, there are two on the bell housing. One is engine speed the other locates TDC. You need both. On the later E engines maybe they went to one?
When you replaced the injectors, did you mark the injector plugs? Possibly cross them up?
Always tough to verify your own work, you tend to assume.
2004 525i Sport, Manual - 1985 325E Coupe Manual
i was going to say to open the oil cap and have some crank the engine over so you can look to see if the rocker arms are moving because maybe the timing belt broke
but, tomstin brings up something no one has asked. is it an e or is it an i? that effects what we are telling you to check because there is a very specific thing that happens to eta cars that will require you to drop the transmission to fix
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and your issue sounds like that specific thing.
No e30s again.
Ok. On eta models, there are the two sensors in the transmission. One of those sensors reads a piece of metal sticking off the flywheel. Sometimes that piece of metal, called a tang, breaks off.
This causes exactly what you are describing.
You can pull the rear sensor, I believe it's the rear sensor, and look in the hole with a flash light while you rotate the flywheel using a flat screw driver through the inspection hole and look for the tang. If it's missing, there will be an outline, or a shadow of a square where it used to be. It's about 1/4"x1/4" square.
I will try to find a pick because this comes up fairly regularly.
https://www.r3vlimited.com/board/for...-swap-help-m20
There is a picture in that thread of the flywheels and one shows the tang. It's called a reference pin in the picture
So your saying that just because one of those tangs could have potentially broken off its causing the car not to start? Even tho I replaced the CPS (Crank Position Sensor)? Is the CPS the one that reads these tangs? I believe so because the other sensor thats right above it is the speed control sensor i believe and I dont think that would keep my car from starting.
The ECU needs BOTH the speed sensor AND the Reference Sensor to start the engine. You can replace the sensor, but if it doesn't have the reference mark on the flywheel to "read" you get nothing.
Make sure the reference mark is there. Make sure you haven't reversed the sensors at the cable connection.
2004 525i Sport, Manual - 1985 325E Coupe Manual
Ok update... i've replaced about everything fuel related on this e30 and it STILL wont start. I am now noticing that the main fuel pump (in tank pump) has these wires that connect directly to the pump part and when I stick my current tester on it I get nothing. Shouldnt there be power going to this wire? I tried it with ignition off and on... nothing. Where does this wire go and how do I trace it to find why there is no power going to it? Yes I checked fuse 11 for the fuel pump... its good. I also tested the relays and did a jump wire to test the fuel pump. Still cant seem to get power to this wire (see photo). Any ideas?IMG_8911.jpg
You can test the fuel easy enough by pulling the fuel hose up by the rail (the return hose) from the pressure regulator to see if you have flow.
To test without motor running - remove the fuel pump relay and connect the sockets 30 and 87 with a jumper wire and a toggle switch in the middle. turn on the toggle to operate the pump...
on your 1987 - do you have a transfer pump?
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1987 can have a transfer pump in the drivers side tank and a fuel pump underneath- somewhere in 87 then they moved to a fuel pump assembly and I think that is in the passenger side.
If you have flow and you get 30oz in 30 seconds - then its not a fuel delivery issue and you can eliminate worrying about the transfer pump / fuel pump / fuel relay (i.e. try starting it with the jumper)
you can also pull the plugs and see if they are wet - inspect clean and replace if needed.
With Spark and fuel verified - then focus on checking the timing marks as stated above - andchecking the 2 sensors on the bell housing..
The TDC position sensor mounted on the front of the 1987 325e model is for use with the BMW service test unit - this sensor is NOT linked to the CPU and does not affect ignition timing. - Only the one sensor (the reference sensor) in the bell housing that reads the Pin from the fly wheel affects the ignition timing. The other sensor on the bell housing is the speed sensor. (You may already know this - if so, forgive me - Im just trying to help as others are)
The reference sensors should end up on your valve cover for the 87 e = Pull the grey one and using an ohm meter - check the resistance between the yellow and black wire - resistance should be (according to the service manual) 960 +-96 ohms. If it is not the sensor is faulty.
There is an old service bulletin (I don't see the number) that references what superj is referring to - a missing pin or damaged pin. Turn the engine over by hand and inspect through the bell housing.
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Next step would be to pull distributor and inspect - look for cracks - test the rotor - make sure your wires are connected in the proper firing order (the cap should be labeled) make sure 1 goes to 1 etc. Cylinder 1 is at the front of the engine.
Ok car is running. However its a little rough idle not super smooth. She'll run good down the road but then after shes running for little i get to stop sign and just dies. Takes bout half hour after cool down then she starts again. Not the smoothest idling in the world either. Next day it runs great. Then next rough idle again. I also have black smoke coming from exhaust. Any thoughts?
As stated in your other thread - It sounds like you have a variety of problems.
Rough Idle is usually caused by vacuum leaks - so I would check for vacuum leaks. The boot is the worst offender. Like I stated before I would take a vacuum gauge and hook it into the intake manifold and look at the readings - Should be around 17 give or take depending.. Main thing is that vacuum is steady.
Black smoke could be rings meaning your engine may be worn out. Your plugs keep getting oily and fouled (see recommendation I made in your other post about keep checking the plugs to diagnose)
I personally would start with checking the compression in each of the 6 cylinders. - A compression checker from HF should be affordable. Pull the Fuel Pump rely, install the tester, push throttle completely to the floor, and crank 4-5 revolutions and then read the gauge.
Your Compression should be in the 140- 160 range.. and all within 10% of one another (roughly)
IMHO - Do these 2 things first to start the diagnosis.
Last edited by 95BMWIC; 05-21-2022 at 01:25 PM.
black smoke can also mean running rich - too much fuel.
general smoking troubles :
blue smoke - valve seals, rings / burning oil
white smoke - head gasket, head / burning coolant
black smoke - air leaks, bad tuning / burning excess fuel
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