Having some engine trouble.

[kowalski]

bmw anything is bloody expesnive

[Jordan]

Alright well the new CPS came in today. Battery was disconnected for ~1.5 days while it was out of the car.

Problem is still there, but I have a nice shinny new CPS. Oh well, it would have really failed soon.

I took the distrib cap and rotor off, both look ok. Cleaned off carbon buildup with a rotary wire brush, and put them back.

Problem is still there...

I took it out on a back road, and ran it through the gears.

1st it starts the misfirish crap at 6k, but will pull through it to 6940.
2nd it starts the misfireish crap at 6k, but will pull through it to 6940 with a bit more struggle then 1st.
3rd it starts at 6k again, and has alot of trouble pulling through to redline
4th it makes it to 6k just fine, then just stops. No misfirish shit. No strugling, nothing. WOT in 4th and it wont accelerate beyond 6k.

This was a flat level road.... sigh. Need to find the culprit before this weekend meet or I won't be going.

[James Crivellone]

Jordan, if you would like I can bring my spare 173 DME down on sunday...

[Jordan]

I really want to doubt it being an ECU problem. But like I said, if its not fixed by this weekend its a moot point, I'm not making the drive to the meet.

[James Crivellone]

I really want to doubt it being an ECU problem. But like I said, if its not fixed by this weekend its a moot point, I'm not making the drive to the meet.

Well stupid questions but

Check your engine harness relays? basic shit like that

[mjc85]

To me it sounds like a cracked head, i read that your car sits on 1/4 temp and wouldn't be suprised if your head is cracked. When i bought my car it was sold to me with a cracked head and did the exact same thing and a few other weird things as well.

Check it out

Mitch

[Jordan]

It's run at 1/4 since the engine was built, 9k miles ago.... head was completely rebuilt, including checking for cracks, and resurfacing. It runs at 1/4 temp because I have a cold t-stat. My head is not cracked.

[robbieosterman]

Okay, I had a similar problem at W.O.T (at higher RPM's) it would hesitate and the RPM's would sputter. It would gradually get to the redline, but very reluctantly.

I fixed the problem by sanding off the spark plugs (they were about 11k old), retarded the advanced valve timing, and put in my old (stock) chip.

After I started the car up, no more problem. Hope this helps.

[kowalski]

latley a lot of people are havin problems with the throttle positiong sensor disconect the battery pull it off and see if you can red line it... could it be a fuel problem? not getting enough fuel at the high rpms? regulator or pump is shot? i duno just throwing out ideas. do a compresion check to see if you'v got a cracked head that way that can be ruled out, should be arround 180-190 i believe. check the spark plugs like robbieosterman said. check your coils. check the plug gaps. fuel filter? also unlikley but could be the purge valve for the emisions controll. what about a vacume leak? anyways those are all the things commin to mind good luck on finding the culprit.

[Fred]

How does the car run under partial load? Does the car accelerate to redline without a problem if you don't floor it, or does the problem only occur under WOT?

I didn't think it would be the crank sensor. If those go bad, your car wouldn't start or it would just quit suddenly while driving.

[Screaming_bmwe30]

although i'm running Megasquirt and a turbo, your problem sounds similar to the one i'm having........and i used to think it had to do with my fuel tables. I have all new fuel system parts....and Motronic is not controlling fuel at all...and i'm sure i'm running rich under WOT...but it still cuts out around 5500-6000, depending on the boost level i am running.

I have a feeling it's ignition related....and slightly fouled plugs could be causing it to miss when combustion pressures are highest. Obviously when a plug is slightly fouled...it's harder for the spark to jump...but when you add pressure as well from either boost or just high rpms'....that may be enough to cause a missfire.

Have you pulled the plugs yet just to see what's going on? Maybe just swap in new plugs anyways....gap them to .025, and see if that cures it. i'm running 2degrees colder witha .025gap when running 10-12psi...but if i run low boost...my plugs sometimes foul....and i get misses at higher rpms, that's why i'm thinking this coudl be the prob. i know with a chip...and an adjustable FPR...i always ran a tad rich at WOT....so maybe that is fouling up the plugs??

[Jordan]

I haven't tried accelerating beyond 6k at part throttle, I will today on the way to work.

While at work I will check my fuel pressure, and the spark plugs.

[86325e]

How old is the CAT? Could be starting to clog. That would affect your top end like that and then just get worse. Have the pressure checked.

[Jordan]

Fred, I can pull to 6940 without any problems at part throttle. (posting from work)

[oh2fly]

Jordan, I know I am late to the party here. To reset the adaption in the ecu, you need to disconnect the battery cables and connect them together with a jumper wire not just have them off the battery. Check for any obstruction going in your intake. At an autocross2 years ago, my car lost 1/3 of it's power. We traced it to the wiring harness for the driver's side H1 headlight sucked inside the opening and blocking off the air to the afm. Just a thought. Definitely check the tps with a meter. Oil inside could cause all kinds of problems. If the tps goes to closed contact for the idle switchwhile accelerating, it will cut off the injectors just like coasting does.