car stops reving @4000rpm and then pops

[Wilson325i]

please help figure this out ,

took the car out yesterday me and my bro, i don't usually lash my grears but i was giving it some, as i took of the lights 1stgear i always stop at 5000rpm (i never red line my car ) but when the car got to 4000revs, we nearly flew out the window coz i was not expecting it, then i took it to so deserted ind est and repeated it, the bloody car red lines when it feels like it. 3/5 the car redlined and the other two the car back fired with a pop plz help

[stanley]

take a look at the REV LIMITED piece in this forum sounds like the same problem.I'm having the same thing happen in my 316i

[coldo]

take a look at the REV LIMITED piece in this forum sounds like the same problem.I'm having the same thing happen in my 316i

And me, had it checked by a couple of mates who know their shit, and none of them have a clue what it is.

[Jordan]

Had a similar problem with my e30. Found the cause to be a worn track in the AFM. The resistance material wears down over time and can create dead spots which really whack out the ECU.

[Jordan]

http://www.r3vlimited.com/Media/e30thep ... 05-001.jpg

[Raz316]

Jordan:
so if it is that problem it's just a case of soldering along the two tracks?

[telski789]

i reckon its the throttle sensor switch on the throttle housing,if it isnt set right or has become loose it wont make the signal for the second stage of fuel/air to come through so your foot is firm on the floor but the engine is starved so bang! you have to check for continuity (the little shockwave sign on the multimeter!) between the middle pin and the outer,the side nearest the windscreen and the middle should beep when the throttle is a gnats cock off the the stop,and the pin at the front of the car with the centre one should beep at around 80% open throttle,if it isnt coming in at all,then no beep and no fuel! these being set wrong are common reasons for flat spots too. maybe your sensor is just faulty.

Tel

[Widge]

Jordan:
so if it is that problem it's just a case of soldering along the two tracks?

Na just give them a damn good clean with some contact cleaner, you'll probably be able to see the corrosion or dirt.

[Raz316]

Widge: Cheers, will do!

[gareth]

worn AFMs are a very common on the 205 gti (which also uses jetronic) and a good AFM clean up on them can work wonders. the contacts on the track itself can often be improved with a graphite pencil...!

[Karan]

what u actually should do is bend the arm slightly so it contacts a cleaner bit of track

[Andy325i]

take a look at the REV LIMITED piece in this forum sounds like the same problem.I'm having the same thing happen in my 316i

Does yours only rev to 4000 rpm under load?

I'd put money on it that its an M40, if it is it will more than likely be the cam worn.

[stanley]

take a look at the REV LIMITED piece in this forum sounds like the same problem.I'm having the same thing happen in my 316i

Does yours only rev to 4000 rpm under load?

I'd put money on it that its an M40, if it is it will more than likely be the cam worn.

no lad it happens all the time

[Andy325i]

Still put money on it being the cam worn if its an M40 dude

[Raz316]

Back again,

I think it is something to do with the AFM because poking around with it while around 4000 revs does make a difference.

Contact cleaner has been mentioned, what exactly is it? I dont want to ruin anything ;)

Cheers

[irish320i]

to check the trootle posistion sensor just disconnect it and try reving it it won t idle but its a quick way to check the fault