Hello all, I have a serious problem with my car. I had been driving down the highway as some of you might have read yesterday, and my car died, so I pull over and finally manage to get it running once again, drive back and all seems well. Well not anymore, because when I go to go to work today, I have a worse problem than just a car shutting off. It will not idle back down without turning the ignition off.

This is a really serious issue for me since to down shift I need to rev it up, but then it just keeps the RPM at whatever you have it at, for at least 5 seconds before it even creeps down. It takes about a full 15 seconds to go back to 1500 RPM from 4000RPM. Not Good.

Oh and to top it off, it doesn't idle anymore, it "idles" at 1500 RPM, rather than 800-1000 like it normally should. I need help because I can't drive like this or I am going to need brakes in about 4 days the way it's going.

I am thinking its a sticky injector, what about you?

Oh and since I don't have an edit function...

The pedal is fine, the throttle linkage and cruise go just like they used to, easy application on, and then springs back like normal. The pedal doesn't stick.

Take out the IAC (idle air control valve or sensor) and clean it with some throttle body cleaner spray I would also check the MAP sensor vacuum line. Thats my best guess.

this may not make sense to you because I dont know what it is called, but, take off your intake, and look at the circle thing that opens and closes when you press on the gas pedal. see if it is sticking open or anything. If someone knows what I am talking about, please explain it better. PM me if you dont understand.


98z24, lowered 2", aem intake, cat-back striaght pipes!, cop ligths in the front and rear, 18" liquid metal's, primer black, tint, full audio and video.

The throttle flap is a tight seal when closed, thats what I made sure to check first.

I think I have found the issue however, when I unplug the TPS (throttle position sensor) it idles perfectly, but when I plug it back in, it makes it rev up more. So I am going to replace that and see where it takes me.

It would not be a sticking injector. I would go with the TPS or IAC. My S10 did the same thing and it was the IAC. Good Luck

My friend had a bonneville that had a @!#$ up Idle. It would go from 1000 up to 2000 and down so low it almost stalled. I think it was just a bad TPS sensor but I don't remember for sure. I will have to ask him next time I see him.

2nd. best guessis the TPS or its wires...Good luck

Mine was doing the same thing, ended up being the TPS sensor.

So should i just replace both and get it over with? I am getting told it could be one or the other, and I need the car for friday to go racing with.

Clipzed Z24 wrote:Mine was doing the same thing, ended up being the TPS sensor.

Yep, same thing happened to me.


PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

Well I went and replaced the TPS sensor today, that wasn't it. The IAC will be in tomorrow, so if that isn't it I have no idea what is wrong with it. I am really hoping thats the problem

And in accordance to my luck lately, I have replaced the IAC and it still does it. I heard that there is a way to calibrate the TPS, is this true? Honestly i am out of ideas and I would REALLY liked this fixed before I go racing this weekend. I like my brakes

1st of all sorry about my bad english... if you figure out how to fix that please tell me cuz i have the same problem =/... mine its a 3 speed aut trans... when i pull just a littl the acel pedal it goes up from 1000 to 2000rmp instantly... i never get like 1500rpm... if i drive it like 40mp/h without pressing the acel pedal it suppose to be at 1200rpm but not, now it is over 2000rpm always... and when i get to a stop the car keep on 2000rpm like for 5 seconds until it downs to 800-1000rpm... or for example when im driving like at 60mp/h and i put on "neutral" it supppose to down to 1000rpm but not... it keeps over 2000rpm... what cpuld be my problem???

I dont know what a ld9 is, but my 91 2.2 had the same prob and had lost one of the o-ring seals on the PCV valve, causing erratic vac draw and thus rpms going wild at times and other times almost normal.