318i M10 shutting off

[AEdward]

Hello r3v! I have been dealing with this for a few days now. So the deal is, stock M10 engine with new plugs, wires, distributor cap, rotor, fuel pump both in-tank and out, O2 sensor, rubber hoses(no vacum leaks) and also tried using spare afm, spare ignition coil, spare fuel pump fuse(middle fuse out of the three on driver side). So what happens is, when i try to start (cold start) initially, it cranks and runs. After about 2-3 minutes when its about to get a little warmer, engine shuts off. Try 2-3 times after, just cranks. Wait a while to cool a little, starts back again, then same thing, warms up a little bit, dies. Even with all the new parts mentioned above and replaced with spare parts, same result. Also, cleaned the ground wires of some oil soaking(read from one of the inquiries here at r3v that oil may cause interference) Any ideas? I try to do diy stuff as much as i can but have no way of measuring pressures, electricity etc. maybe someone have any experience with this that have resolved the issue. Thanks r3v!

[packratbimmer]

Coolant temperature sensor in thermostat housing. Car will not run without it. Think about a burned out incandescent light bulb that will come on when the broken filament is hend a certain way.

[AEdward]

Coolant temperature sensor in thermostat housing. Car will not run without it. Think about a burned out incandescent light bulb that will come on when the broken filament is hend a certain way.

I actually have the part, haven’t installed it yet but will definitely try that, thanks for your reply!

[AEdward]

Ok so replaced the temperature sensor, had difficulty starting at first, but had luck starting it and running back again. Then about 15minutes of test-driving, car died. Did not want to start again, back to same problem. Any more ideas? Trying to see if i can source out an idle control valve locally to see if that may be the problem.

[loki_]

You've already replaced my top 10 suspects. The next two things I can think of would be a clogged cat or a failing distributor.


To check if it's a clogged cat, you'd connect the gauge to an intake manifold vacuum line. Start the engine, let it idle, and check the reading on the gauge. This is your baseline vacuum. It varies by the engine but should be 7.5-11lbs of vacuum (16-21inhg).

Have a helper increase engine speed to 2500 rpm and hold. After a brief drop of a few seconds, the gauge needle should return to approximately the same vacuum. If the needle is slow to return, or stays low, the cat is blocked.


to test if the distributor is about to go out, run your car in the driveway until it stalls. The pull a plug wire off, put and old spark plug in it, and hold it so the end is by the motor, like a bolt, and have a friend crank it. You will see a spark if the distributor is ok.


i hope this helps

[MrBurgundy]

Check your cold start valve, it might be leaking to the point where the plugs get too soaked to spark

also the plunger on the fuel distributor can get stuck down and flood the engine,.

[AEdward]

You've already replaced my top 10 suspects. The next two things I can think of would be a clogged cat or a failing distributor.


To check if it's a clogged cat, you'd connect the gauge to an intake manifold vacuum line. Start the engine, let it idle, and check the reading on the gauge. This is your baseline vacuum. It varies by the engine but should be 7.5-11lbs of vacuum (16-21inhg).

Have a helper increase engine speed to 2500 rpm and hold. After a brief drop of a few seconds, the gauge needle should return to approximately the same vacuum. If the needle is slow to return, or stays low, the cat is blocked.


to test if the distributor is about to go out, run your car in the driveway until it stalls. The pull a plug wire off, put and old spark plug in it, and hold it so the end is by the motor, like a bolt, and have a friend crank it. You will see a spark if the distributor is ok.


i hope this helps

May have to check the first one a different way just because it’s really difficult to start the car. It basically starts when it wants to now. I probably just got lucky earlier. But the second one i can definitely try right now and see if i get any spark.

I really tried reading and back reading until i’ve exhausted as much info as I could from here before buying parts and before posting also.

Check your cold start valve, it might be leaking to the point where the plugs get too soaked to spark

also the plunger on the fuel distributor can get stuck down and flood the engine,.

Both these I haven’t touched yet, will get to it tomorrow also together with checking for spark.

Thanks for your inputs guys!

[AEdward]

Okay, tried to see if cold start valve was working at all or what it looked like. Pulled it out, little dirty, cleaned with carb cleaner and tried starting the car while it is out of the hole from the flange. It sprayed gas during crank. Placed it back in, started the car and at first it wanted to turn on. But afterwards, same result it stopped and just cranked. Pulled it back out, started the car while out, no spray.

Had an idea, I have a 325e intake manifold that i took off from a previous donor, to my surprise, it had the same cold start valve on there, took that off, cleaned it and replaced the original one from the 318. Before placing it back in the hole, started it and saw it spray gas. Placed it back in the hole, started the car, again. It wanted to start and idle, but no luck. Took it out again and started the car, no spray.

Back to same no start problem. Not sure if its because its hot outside and engine is somewhat warm thats why its not spraying or should it continuously be spraying?

I should mention that it did start the other day when i got a replacement icv, drove around for a while, then thought it fixed it. Had another idea of replacing the original icv back to see if it would cause the no start and put the new used one to see if it would start again. Well, it didnt die. It still ran fine, either with the original or the new icv. Turned the car off. Poof, no start. Again.

Any ideas?

[loki_]

I've had my cold start injector bypassed for years and it shouldn't affect anything unless it's flooding the engine. Did you verify that you're actually getting spark to the plugs? You're absolutely positive that you don't have any vacuum leaks? I had an issue a few years ago where the oil dipstick wasn't sealing properly and was causing a vacuum leak.

Since we're grasping at straws, I had an issue a few years ago where I hit a gigantic bump in the road and the connector for the DME came unseated by the tiniest amount. This caused the car to crank but have a very difficult time running. I pressed the connector back on firmly and everything immediately went back to normal.

[AEdward]

Thanks for all the inputs again guys! Got the car back up and running again, big thanks to Guten parts! Very lucky to have them real close to where I live. Anyway, so the problem was the ecu. And the reason why the ecu had failed was because of the elephant grommet. I remember Guten had actually posted that on their instagram once and never bothered checking that when i got the car. Water was getting in and soaked the ecu. Which caused the injectors not to fire. That was it! Case closed and again, if you guys need any help and havent heard of Guten parts, now you know!