Problem with revs cutting out around 5500rpm

[Nick325is]

For awhile now my car has been having a problem with cutting out around 5500rpm. This happens when I have the gas pedal all the way to the floor. Once the rpm hits around 5500 the car just looses all power and will not go any farther. If I let off of the gas slightly the revs will go all the way up to redline. This problem does not happen if I have the gas pedal in any other position than WOT. Even if the gas pedal is just slightly away from being floored the problem does not happen.
I replaced the fuel filter and throttle position sensor and the situation did not improve. Is there a way to adjust the TPS? I know there are two screws on the bottom of the unit.
I am thinking that the problem is the TPS because when I hooked it up to the diagnostics machine it said that the TPS was working at idle and partial throttle, but not at WOT. I replaced the TPS at that point and the problem is still happening,
Any ideas?
BTW the engine is an m20.

Thanks,
Nick

[BavarianBimmer]

When I was reading your topic i tought immediatly on your TPS 'cause it has the same symptons

- was it a new TPS ?
- do you've checked your wirings ?

I still would go fot an TPS malfunction :?

[Nick325is]

It was a brand new TPS from BMW.


Nick

[BavarianBimmer]

:roll:
in worst case you've a bad ECU
if you can try/borrow a spare ECU i'm just guessing now maybe gives you that an issue
your problem is going out of my technical knownledge :oops:

[Stu]

I have a similar problem with my car. At WFO, it will cut out at anywhere from 6000-6600, but it's like a sudden 'jerk'.

The wierd part is, my car ALSO did this with the 4 cylinder, it would cut out early in the same way.

I don't have any suggestions for you, because I am equally as lost.

[Jarvis]

Nick - you're not using any aftermarket chips in your ECU, are you? Be especially wary of those rip-off "Pro-Formance"-or-whatever chips on eBay. I'm guessing the problem lies somewhere in the ECU or whatever chip is currently in there.

[Nick325is]

I have the stock chip in the ECU. The car does the same thing you are talking about Stu. It all of a sudden just jerks and cuts out. This is concerning me.



Nick

[skat 325is]

Speed sensor ?

[mspiegle]

well, can you swap ECU's with someone? Also, hookup an AFR gauge and see what happens at that point.

[Kavkazia]

Speed sensor ?

I'm thinking same, either motor flywheel sensor, or flywheel it self is cracked or damaged.

(00MPH!) George had similar problem, we switched AFM/ICV, new wires, tune up, switched ECUs still nothing, so it turned out what I just mentioned.

[Bill 84 318i]

325i's shouldn't have flywheel sensors.

Or do they?

[Kavkazia]

325i's shouldn't have flywheel sensors.

Or do they?

If you look down bottom of dist. you'll see little sensor on top motor flywheel. It's aluminum looking piece with black top, and has little wire running from round motor diagnose thing to motor flywheel. It has two plugs on bottom of black round motor diagnose thing, one is rev. sensor, and other speed sensor.

Sorry for my english.
:oops:

[skat 325is]

In front where the harmonic balancer is, theres a speed reference sensor, mine was damaged and my car would like redline around $5,500 rpms, u can see it clearly near the oil filter but in the front of the engine.

[Mitch M]

Re:

Check your DME #. I bought a 87 iS a few years back that had the "154" Super ETA DME
~5500 rpm cutoff vs. 6400 for std "i's"

[Nick325is]

I will be checking out the speed sensor then. Is there any test to see if it is functioning correctly?


Nick