Missifre after a few minutes of warm up.

[Makaveli2k]

So once again,

Car starts up fine, let it idle for a little bit idles at 750 or so rpms. Once It gets out of the blue on the temp gauge and then the idle drops down to 350 ad the car starts to shake.

Here's what I think:
-If coils are the culprit, wouldn't it act funky from the get go.(I haven't pulled them yet so they could still be a possibilty but I doubt it.)
- Car is throwing a code for bad Maf, I'll replace it but I don't think that's what's causing this either, because the symptoms exhibited don't sound like a bad Maf, Or could it?
-o2's are out of the question, Let's just say the Kitty's weren't implemented when I had the "House" built.

This problem started after I swapped out battery's but I don't think that could be the cause of the problem.

TIA
-Dan

[Jehu]

ICV? You need to put your Car Model ,Year and Mileage in your profile so it appears with your name..

[Makaveli2k]

Appologies and done.

Would an ICV cause this, would it not just make the idle crap from initial start?

ahh I'll add it to my list.

[Jehu]

Have you ever changed fuel filters? Water in the gas? Try a bottle of dry gas or something like that if you left the tank low and live in an area where the temps are cold. Looked at your spark plugs? How about the coil boots .. distiributor,plug wires all good? Not loseing any spark from an arcing ignition wire?

[Makaveli2k]

Fuel filter, I tested fuel at the rail when the motor wouldn't run and it was all within spec.


Water in Gas, Not quiet sure, I'll try the dry gas thing.

I did leave the tank extremely low but ti still has enough gas in it not to trigger the amber reserve tank light.

The coils and the boots I'll check them all on Thursday(next time I get access to the car) I'm going to try unplugging the coils individually seeing f I'll get to one that doesn't affect my idle. Then that may narrow down the culprit.

[bubba966]

Quick MAF check is to unplug it then run the engine. If it idles better with the MAF unplugged then your MAF needs replacing.

Buuuut, a vac leak throws a MAF code. That's the more likely issue from the sound of it. The MAF on my M-Sport is bad and it idles just the same hot as it does cold.

A coil could change behavior when hot as the heat generated by the engine could warm it up to a point to where part of it has expanded slightly and is causing a misfire due to cracked insulation.

But it sounds like either a dirty/frozen ICV or vac leak to me. Could be a coil, but would go for ICV/vac issue first.

Check part #9 here http://www.realoem.com/bmw/showparts...24&hg=11&fg=40

It's what connects the ICV hose to the intake manifold. Has a habit breaking off the retaining clip and working it's way out to create a vac leak. Easiest way to check it is to pop the throttle body off the manifold and look inside the manifold where the throttle body was connected. That plastic connector is right there and easy to see if you do that. And it's only about a $6 part at the dealer if that's your problem.

[Interceptor]

Coolant temp sensor? Leaking injectors? As said before, I would check for vacuum leaks first.

[Makaveli2k]

Checked all coils and plugs, they seem good. Although they are those dreaded Bosch Platinum 4 prong plugs that don't have too great reviews.

1 of them was funked so I changed it. Helped a bit. But I'm still getting a low idle and a missfire.

Misfire doesn't seem to affect when I'm leaving in first gear but while driving to the storage facility I had no second(I stupidly put in a e36 shifter lever, so I don't think I have enough travel for the rod to fully put it in when I put it into the bottom gears.(I think that may be attributed to the maf)

So I'd get out of first and then go to third, and then I'd get misfire.

I'm also still getting a low idle, it doesn't jump all over the place it stays consistently at like 400 or 475 rpms. I get this if I start it cold or let it warm up, no difference.