Annoying Problem

[ronald_r32]

Ok here is the problem, i have no power above 2500 revs, it will go up to here fine then once it hits that point then it will just stop like it is not getting any pertol. When it is doing this problem it will idle at about 1500 - 2000 revs instead of 500 - 1000 revs. Now this does not happen every time i drive the car and there is no common pattern that makes it do it.

I have had the car services and the mechanics cleaned out the injectors, put a new fuel pump in, checked the fuel pump, changed spark plugs and a heap of other things and could not find anything that is making the problem.

The car is a r32 gts-t (rb20det) with a 3" exausht from turbo and a 5" tip, and a HKS pod filter. Any help would be great as it is making the car so hard to drive.

[GTRsean]

AFM problem?

[ronald_r32]

Whats that sorry?

[blind_elk]

The 5" tip is your problem - too much bling for a R32 GTSt.

Seriously, though, if you searched these forums you would have been able to uncover that fact that a dead or dying AFM (Air Flow Meter) will set the ECU into limp-home mode and will not permit the engine to rev at more than 2500.

[JimX]

2nd vote for 5" tip being the problem.

[ronald_r32]

it was imported with it, and the problem has only just started happening like in the last 2 weeks, and ive had the car for about 4-5 weeks. So i doubt that is the problem.

[ronald_r32]

my bad its only 4"

[nismo33]

there's no harm in trying to borrow an AFM from your mate and see if it was the problem.

if the car runs the same -- then we source out something else

its called -- troubleshooting my friend.

[JimX]

my bad its only 4"

<{POST_SNAPBACK}>

Hehe, in that case maybe you need it upgraded to 5"

Seriously though, it's almost certainly an AFM problem. I've had a similar thing happen when I accidentally yoinked out my S-AFC awhile ago, which among other things, severs the signal wire from the AFM. I also recently have my AFM die a half-arsed death, which resulted in the car being unable to idle, although I could get above 2500rpm in that case by keeping the throttle open.

[sewid]

Yeah its almost gotta be the AFM. Try this; unplug your AFM completely, your car should do the same thing (wont rev past 2500) all the time now.

Get a new AFM and see if that fixes it.

[ronald_r32]

how much am i looking for a new afm?

[Baz]

Why not just run an ecu diagnostic rather than playing guessing games to see what your problem is? That will give you a definative answer to if your car has a bung AFM. Idling problems can be caused by an excessive amount of things just to name a few dirty/in-op/incorrectly set AAC valve, incorrectly set idle via throttle plate, carbon buildup on throttle plate, AFM problems, air regulator and the list goes on....

Do a seach and that should fix your problem.

[Baz]

Genuine nissan AFM's are very very expensive items btw

[ronald_r32]

Like how much? does it have to be genuine nissan or is there other types?

[JimX]

Second hand should be around $150 or less. Try Ebay, you might be lucky. If not then JustJap should have one and they deliver too. Test it before you go and buy one first, it could just be a bad connector or something. See if you can borrow a known working one from someone and hook it up.

[ronald_r32]

Going to the mechanics tomorrow to have it hooked up to a diagnostics computer. Hopefully it is just a bad connector as this will take away money from my FMIC

What would cause it to go into limp-home mode, as it doesnt always have the problem?