High idle speed problems ( possible causes )

PobodY

Moderators
Staff member
since i installed my walbro pump my R idles at 1500rpm and is killing me in petrol should i install a fuel pressure regulator?
No. Just find out why you have such a high idle; if the injectors aren't firing it will be returning most of the fuel to the tank anyway, so something is telling the ECU to keep throwing fuel in.

Try the TPS, or maybe your MAF.
 

GTIR-NZ

Member
Hi GTIR guys, i recently got a GTIR and it has been revving quite high at around 1200-1500 when cold. However, i drive it for about 5-10 mins depending on traffic and whether im stopped in it and then the idle increases to around 1500. If im not moving for a couple of minutes and then i go to accelerate, the revs die and come back and then die and i bunny hop! I turn the car off, wait a minute and then start it and it runs fine.
However, now my revs are below 900 and i am getting a very sluggish response when accelerating. The info above is very helpful and will be looking at this over the weekend, just hope the neighbours are out as the car is bl##dy loud!
I had a similar problem on my Skyline and it turned out to be the solder points on the MAF, would this be similar? Any comments would be welcomed!
 

simigeri

Member
UP!

What's the easiest way to check the AAC, FICD, air reg ect back of the throttle?
The Y bracket still in, but when I'm first trying the ALS function (I know, it's dangerous :) ) lost my 950rpm idle. It goes to 1600 rpm whit correct AFR, but when I changed back the factory ECU, idle drops to 1000, but 20-22AFR (whit 560 injectors!!!).
So I think is there some leaking, or some of these air regulator valves freaked out.
I'd like to check them, whitout remove the engine :D
 

Slunch

New Member
Are you getting misfires at idle, when the car warms up does the idle decrease. What do your plugs look like? If the air was 22 it wouldn't be running. Check for an exhaust leak around or up stream of the wide band sensor.
 

Hardy172cup

New Member
I had a similar problem to this, my idle went really rough and my AFR was jumping around between 19-22. I had blew a pipe off that went between two of the ports for balancing the throttle bodies
 

simigeri

Member
I had a similar problem to this, my idle went really rough and my AFR was jumping around between 19-22. I had blew a pipe off that went between two of the ports for balancing the throttle bodies
The plugs of the throttle calibrating holes at cylinder No 1-2 was popped out.
 
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