FIXED: Stuttering at 3k RPM.. has anyone figured this out? --- VIDEO INSIDE

[snitzer]

Nairb,

does your m42 have the adapter harness in place?

[Nairb]

Thanks Jung, will do!

[JUNGLISTluder]

I plan on pulling the engine, sealing it up a bit better, replacing whatever the fuck I see, and dropping it back in with a lighter flywheel.

I feel you Jake.. I have spent a lot of time and money making this thing *like new* and this is the worst symptom it could possibly have. A 3500 rev limiter on a fucking high-winding 4-cyl is terrible!

Gotta stay motivated and get this shit done soon!

I had all the exact same symptoms as you. 3500rpm limit when warm and 1244 code. A new crank sensor fixed it. My old one even tested within spec. I don't see that you replaced this sensor, so I would really start with that.

[Nairb]

I plan on pulling the engine, sealing it up a bit better, replacing whatever the fuck I see, and dropping it back in with a lighter flywheel.

I feel you Jake.. I have spent a lot of time and money making this thing *like new* and this is the worst symptom it could possibly have. A 3500 rev limiter on a fucking high-winding 4-cyl is terrible!

Gotta stay motivated and get this shit done soon!

[TurboJake]

Try Replacing the engine harness.

As luck would have it, I have one I can sell you.

I'm currently working on replacing the harness for my own E30, because it's doing the same damn thing. It sucks having a relatively nice 325i, that I have to shift like an E. I just pulled the harness out of my parts car not an hour ago, and found a couple previously fixed wires. So I'm gonna solder them up, and put it in. It's the only thing left that makes sense on my car. Everything else (Fucking everything, I even upgraded to a miller MAF and war chip because of this), has been replaced.

You can see a video on my post about this (It was taken early on when it was intermittent, now it's an extremely consistent 5k. The check engine light is pretty much a shift light). A lot more dramatic than yours. But maybe it's a possibility.

http://www.r3vlimited.com/board/showthread.php?t=227835

[snitzer]

My car is missing the adapter harness for the AFM... didn't know what it was a couple of years ago... took it off and didn't have any issues .. now i know it was put there to correct an idle issue and am wondering if i should find another one and see if it fixes the stuttering.

[JUNGLISTluder]

fixed my issue with a new Crank Position Sensor!

[snitzer]

I did the cleanup of the cps.... no improvement... there is a small stumbled from idle when i start to accelerate.

[mangomango]

you guys might want to check that your crank sensor is clean. mine had a bunch of gunk on it and it did the exact thing your describing. ... however i replaced it with a known working one and now the car runs great all the time. that and or vacuum leaks off the intake boot. i had one fall off that i didnt know while i was swaping afms and it didnt run for crap.

but check the cps to make sure the tip of the sensor is clean. that might work.

[snitzer]

I'm have similer issues... i checked my crank sensor... it was .555 ohms. it's either bad or i had the meter on the wrong range, should it be around 640 ohms with no decimal point?

[JUNGLISTluder]

Bumping this thread. I have the exact same problem. Only happens when the engine is warmed up. Feels like the rev limiter is kicking in at random rpms, anywhere from 3.5k to 6k. Drive great when cold and will rev freely, but as soon as it warms up you can feel the problem start to happen. Gets worse as car warms up. I'm also getting a 1244 code when I do the stomp test. I did remove the cam sensor when changing my thermostat, but don't think I damaged it.

Recent maintenance:
Spark plugs 12/2011
Fuel pump 12/2011
Fuel filter 12/2011
Thermostat 12/2011
Engine ground strap 12/2011
Rebuilt Injectors 11/2011
Cleaned mess under intake 11/2011
Ignition wires 01/2010
O2 Sensor 01/2009

I tested:
Connections for crank and cam sensors
Crank sensor reads 584 ohms
AFM wiper arm reads 350-900 ohms as flap opens, but dips to 600 for a moment near full open. Not sure if that's normal.
FPR ok. Has no fuel at vacuum line and rpms rise when line is disconnected
Tried stock ECU chip and Turner chip. No difference.

I have not tested the cam sensor, O2 sensor, or ignition components. I'm thinking the ignition wires are messed up because they run directly above the headers. Would this heat cause the ignition to mess up as the car warms up? My symptoms are exactly as descriped by the OP in this thread and only started happening the past week or two. I'm thinking of trying the HQ COP kit, but the OP already has that with the same symptoms. So frustrating!

Help! :(

[mangomango]

Hey, i replaced the CPS and it fixed my problem. its definitely a pain to do but is possible. However i was also told if there is build-up on the sensor like a heavy grease that it can mess up the signal.

i did replace the AFM at the same time too. but it did run the same with the original one but I also believe that my AFM is crapping out. so Both the CPS and AFM were replaced and now it runs fine.

[Nairb]

About to sell this mofo as is.. anyone want an awesome condition, barely running 318is..?

:(

[mangomango]

yeah. . . its frustrating as hell. you said yours does it when its cold now too?
Because mine is fine when i first start it up. but as the car warms up the worse the problem will get. as in it will go to 6k, then drive for a little bit and accelerate and it'll only go to 5k and so on until it only does 3500.

I'm waiting for a cps and afm both used but out of good running car. we'll see what happens i guess.

[Nairb]

Have not had adequate time to diagnose the problem yet.

Believe me, I will post once I figure it out... pissing me off. :|