Engine stuttering occasisonally

[halcron]

When I start up my car, I notice that the engine is stuttering at times. Its as if the engine miss a beat or something. This happens esp. when the engine is cold. It gets better as the engine warms up but still happen.

When I step on the accelerator, its as if the engine stalled for a very brief period of time then continues. It started happening around 2 weeks ago. This only happens at low RPMs of around 1-2K though. No problems with higher RPMs.

Any idea whats wrong with the car? Could it be due to the spark plug not firing at times? I am using the Brisk LGS Premium plugs but its already pass its recommended lifespan of 30K so I am wondering if changing plugs will solve the problem.

[vonkamp]

It can't hurt to change them.

Check out this thread then take a look at yours.
The mess under the intake (http://www.m42club.com/forums/showthread.php?t=2742)

[xwill112x]

maybe check vacum hoses?
those seem to cause problems like this.

[EN318isPDX]

my M42 had vacuum issues and also had a weak fuel pump which caused it to have alot less power and it "hated to get up and go". Literally felt like 1/3 the HP to what its like now.

[91 318is]

bringing this back up, did you ever figure out what was wrong? I have a 91 318is and it's doing the same thing, some said it may be the coolant temp sensor that runs the computer, but I haven't changed it yet.

[GrindCulture]

Odd I should stumble across this thread as mines been doing it over the past few days, it also smells like fuel under the bonnet sometimes, so I'm gonna have a look under the manifold and inspect all the fuel lines. The plugs are very new, not quite done 1000 miles with them yet, but my rocker profile gaskets (most prolifically the spark plug gasket on cylinder 1) are leaking a bit letting small amounts of oil seep into the spark plug gasket. Could this be contributing? Maybe preventing a strong enough spark?

[deltaneo1]

try a fuel cleaner system it could be the injectors not working right and might cause a stutter at low RPM's ..
Oh and one thing may be dumb to say but air cleaner checck it .....
a stumble is from lack of fuel or air .... hope this points you in the right way

[AcSchnitzer318is]

ahhh yet another sufferer of this issue. Good luck, some of us have been fighting this issue for a year or more.

[marko]

check your mass air flow sensor - if its busted it will send a signal to the ecu 'no incoming air' - & in return the ecu will shut the fuel off... I had same cutting off issues - it was a bad MAF sensor.

[EN318isPDX]

try a fuel cleaner system it could be the injectors not working right and might cause a stutter at low RPM's ..
Oh and one thing may be dumb to say but air cleaner checck it .....
a stumble is from lack of fuel or air .... hope this points you in the right way

I thought the same thing about this issue but i replaced my injectors and i still have this issue

[JP 91iS]

damn, there's an E30 M42 plague going around... hope I don't catch it

[RedHoodRidah]

Oh god this is funny....I caught it a few days ago.

Changed the fuel pump since it was loud as hell and bad anyway.

[sports.racer]

Very annoying. With mine, it's warm start, just not always. Cold it starts just fine and runs great. After it's warm and you restart it'll idle like crap, sometimes die, sometime not. Sometimes the check engine light will flicker while it's coughing, sometimes not. Let the thing idle for about 20 seconds and it will come back around and run good again.

Usually smell fuel which kind of makes me think an injector is sticking open.

Fault codes, stomp test and Peake reader point to #1 cylinder coil. Replaced the coil pack (I did the COP mod) and that didn't help.

[AcSchnitzer318is]

^Yep same exact problem most of us are dealing with. LOL we should all chip in a few bucks to the guy who figures this out. My car has been doing it now for over a year. But runs awesome after warmup, or on complete cold start.

It's something external to the engine, I've replaced everything that would cause this on the engine (AFM, injectors, plugs, wires, tps, engine temp sensor, vacuum hoses, fuel lines, fuel filter, etc, etc.

[JP 91iS]

What about the exhaust? gaskets, o2 sensor, cat?

[AcSchnitzer318is]

That's my only avenue left. I know I have an exhaust leak before the o2. I replaced the o2 and the car was awesome for about 5 hours with multiple warm starts. Then it started doing it again and has done it ever since.

Going to do a COMPLETE new exhaust system and see if that helps.

[RedHoodRidah]

Well I found out where mine was coming from. Did a compression test and cylinder number 2 is very low compared to the rest.

Cyl#1-215 Cyl#2-102 Cyl#3-235 Cyl#4-235

[Birdman16]

I have the same problem, should have put my thread in this section. Second the motion to give MONEY to anyone who fixes this problem clubwide.

[txleadfoot]

I have a new 02 Sensor and that didn't help. New injectors as well.

[xwill112x]

mine does it occasionally...but only after cruising at low rpms...then pushing the clutch in...
it only does it 1 time out of 56736536599 times of pushing in the clutch...so not very often..

i think it may be a pesky icv...