Stalling At Idle/low Revs

[Bodella]

My Stagea has started to stall at idle/low revs. I am assuming it it is a fuel flow problem and will replace the fuel filter this weekend. While i am at it I will change the air filter, clean the afm with contact cleaner and have a look at the fuel pump for problems/dirty fuel.

Is there anything else that is an easy fix?. I want to make the putty rd cruise and will do the obvious, easy stuff all at once.

[Springsteen]

aac valve full of crud? a bit more tricky than just squirting out your afm but similar problems reported by other members.

[Bodella]

cheers for that , reading some threads that suggest this should be high on my list for a fix.

found this thread , http://www.skylinesaustralia.com/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/page__st__120

May be beyond my scope of works for today , but god damn it I want to drive Putty rd tomorrow.

[Bodella]

okay that was a fail. no putty road for me.

Some details

Car C34 s2 rs4s - stock in the engine bay.

stalling at idle, hunts around, splutters , then dies. If left for 5 min restarts. if the revs are kept up , no problem.

I have changed the fuel filter

Changed the air filter.

Didn't do the afm today as I have to go out. Do people think this could be the cause? will try tomorrow morning.

The above guide for aac clean is for a r33, and the neo appears to be different, plus I'm not comfortable yet doing this job. SO it's off the mechanic because I love giving them all my money.

[Bodella]

okay tested theory that isthe idle control. Cold start is fine, once it warms up a little the acc kicks in and it splutters, then stalls. It will not restart until cooled down.

Off to repco for few bits. The process for the neo is a little different, same idea.

[Bodella]

Okay, fingers crossed, it looks like I have fixed my problem.

Cleaned the AFM and Acc today. I am convinced the acc was the problem, due to the level of carbon deposits. Car has done 100k so no surprise. I'll need to tweak my idle speed, sitting at about 900 rpm ( should be 650 ) but I'll wait a week to be certain the problem is gone.

See this thread for NEO specific directions. The fourth bolt down the back is a bitch to get out.

http://www.skylinesaustralia.com/forums/topic/344264-cleaning-the-aac-valve-on-rb25det-neo/

I highly recommend this be done as preventative measure. If you are worried about the skill level required it is very easy, just take your time and follow the instructions.

time for a Homer dance ..

Let's just hope my car doesn't burn down.

[Bodella]

so ... went for drive ... problem came back. popped the bonnet, Fonzied the air box and the car started. I have cleaned the AFM again and will go for drive latter.

However I think it is time for new AFM.

damn.

[wolverine]

They are easy to repair even for a nuff nuff like me. Soldering iron and stanley knife required.

[Bodella]

an update of no success so far.

Pulled out the AFM , one of the techs at work re did all the solders ( complete de solder and re solder ). Got the car through pink slip no problems but it failed again while driving to work.

Plugged a cable in to check for error messages, nothing. Had the laptop plugged in today while I went for a drive, stalled and again all I had to do was give the airbox a whack to get it started again. There is no drop in voltages on the afm in the logs, so will continue to hunt out my intermittent fault.

I'm now over it but will have to wait for funds to send to a mechanic.

[PN-Mad]

could you check wire continuity to the AFM pin on the ECU? maybe the wire has intermittently earthed somewhere. If not, then get your techs to inspect the ECU for joints that are suspect?

I'm just playing along at home....

[wolverine]

I would have a very thorough look for a vacuum leak as well. There are lots of little vacuum hoses that can open up when hot and cause hunting and stalling. It still seems like another issue but the simple things are worth checking out. Particular attention to the small hoses at the front of the plenum as they are often missed.

Whacking the airbox sounds awfully like AFM/AFM wiring is the culprit. Are you certain that the tech re-soldered the afm correctly? If so, then it is the wiring around the plug.

[Bodella]

Thanks guys, I would thought I'd see an error message for drop in voltages if the AFM was faulty. It's now booked in at ASR for later in the week, will let you if it is solved.

[scotty nm35]

No error messages, just a lower voltage to the ecu causing lean conditions. Solder the pins on the board where the plug goes in again, if all else fails change it.

No point taking it to a workshop to diagnose until that's done at least, as that's what they will do first.

[Bodella]

sorry muppet at the Keyboard -

Thanks guys, I would thought I'd see an error message OR A drop in voltages if the AFM was faulty. It's now booked in at ASR for later in the week, will let you know if it is solved.

There is no drop in voltages. ( that I can tell ) but I will try to get another to swap in this week.

I have no idea what I'm doing in general, so I'd like it looked at. On the bright side I have learnt alot and gained confidence in doing stuff for myself.

[wolverine]

No error messages, just a lower voltage to the ecu causing lean conditions. Solder the pins on the board where the plug goes in again, if all else fails change it.

No point taking it to a workshop to diagnose until that's done at least, as that's what they will do first.

Andrew @ ASR is a good guy Scotty. If the car is down there Thursday morning I will pop in and have a look too.

[dirtyRS4]

Whacking the airbox sounds awfully like AFM/AFM wiring is the culprit.

this is very common in stageas.

imho would likely be afm