acceleration stops dead at 5.5k

[skuyler]

i've been driving my e36 for a few weeks now with the e30 parked, and took her out this weekend. everything was pretty much fine, except once, (out of the dozen or so times) when i was gunning it, the revs went up and cut around 5.5-6k. it was very unsettling because the car never used to do it. i changed the oil and seafoamed the car, but its still doing it (consistently now). i believe it is a fuel issue, but maybe some of you gurus have wisdom for me. thanks

[skuyler]

okay, so i drove it around again today to figure things out. after warming it up a bit, i took it to the top of the revs, and it redlined at 6500 (which is weird because my MarkD chip has redline at 6900). I drove it around a few more minutes, then it redlined at about 6. Then, after a few more minutes, it consistently redlined at 5500. It would just hold and bounce there like it was actually the redline.

It just occured to me that it could be the chip. I hope not, but does anybody else have other guesses?

[e30pwr]

I'd put the original chip back in and see what that does. Than go from there.

[redhatpat]

Could be a fuel filter starting to get plugged up. Can you hold revs at 4-5000 for a minute? That'll be a decent test of the fuel filters flow capacity.

[skuyler]

see, i was thinking that could be it also. the thing is that i changed the fuel filter less than a year ago. i hope its not the fuel pump. i'll check the ecu/chip soon, since the car basically thinks its an ETA now

[Rolla1990]

The catalysts could be broken up and clogged. Unbolt your exhaust and see if that fixes it.

[skuyler]

good god i hope not. also, between 4k-5k, the power surges or gets "flatspots," like its not getting enough fuel. i don't know, i sure hope it isn't the exhaust.

[devonjordan]

I was going to say, is your car an eta?

[skuyler]

first, i checked the chip, and it was able to click in a little bit more, so i thought that might have solved it. it didn't, i don't think anything felt different.

then i completely changed ECUs, to a stock 173. the car ran fine, but consistently redlined at 6k (should be 6.5, right?). so i guess that means it isn't the ECU, although the car still doesn't know where its redline is. that could mean exhaust I suppose, since it may be getting stuck up at different temperatures.

any other guesses? ideally, i've wanted to sell the car, but don't wanna sell a not perfect car, and don't want to drop a lot of money on it