Car won't idle down

Ira R.

Registered User
I am going to try and figure this out if it kills me!! It's a simple story. Once the car has warmed up it idles down and runs fine; until you move the car.

First gear to the end of the block, second gear around the corner, bring to a full stop at the first real intersection, depress the clutch and the idle hangs around 1100-1200. And it will almost always stay there. It almost never idles down on its own. Take the car out of 2nd gear and it idles right down.
If I have not come to a full and complete stop the idle will hang until I do and shift out of whatever gear I am in. If I put it in 1st too soon while coming to a stop it will hang and I have to take it out of 1st again to bring the idle down.

Put the car in 1st, enter traffic and drive. Come to a traffic light in any gear and come to a stop. Idle hangs until you have come to a complete stop and shifted out of 3rd or 4th. Idle drops. Shift into 1st, kick the pedal and roll slightly forward, depress clutch and the idle hangs again. Take it out of gear and it idles right down again.

This is all on a warm engine. On a cold engine the same symptoms exist but the idle rpsm's are higher and the prblem is more pronounced.

I have already replaced the sensor in the transmission and it made no difference. Now I want to get some feedback before I just start replacing parts for the sake of it.

Anyone else ever have this issue??

Ira
 
I had something very similar and chased the IAC as well as the TPS to no good. Finally my mechanic traced my problem down to a massive vaccuum leak. All the injector seals were rotten and the intake gaskets were leaking. He tore the whole intake apart, replaced the injector seals and all intake gaskets. End of problem and has run perfect ever since. Before the annoying high idle problems I had other problems with drivability. All are gone now and it hasn't run this smooth in years.

I noticed a difference in my vaccuum gauge as well. Before I had problems it would pull a good 26 - 27 inches under strong decel. While I was having problems it wouldn't pull that much under strong decel. Have you noticed any decrease in your vaccuum?
 
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My car does the same thing. The car will never idle down in neutral while it is moving. It will idle down once it has been at a complete stop for xxx seconds. I asked Ricardo about this and he said this was a setting in the chip. I'll pm him to reply to this thread.
 
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I think it has to do with the Dash pod setting on the tune. I have the same symptoms from Engine one Till engine 3. Chances of me having a vacuum leak on all three of them are slim. I would ask Dalke. I belive the chip has a way of playing with the dashpod settings.
Mine drops once I reach a full stop. But when coasting I get a high idle.
 
I had something very similar and chased the IAC as well as the TPS to no good. Finally my mechanic traced my problem down to a massive vaccuum leak. All the injector seals were rotten and the intake gaskets were leaking. He tore the whole intake apart, replaced the injector seals and all intake gaskets. End of problem and has run perfect ever since. Before the annoying high idle problems I had other problems with drivability. All are gone now and it hasn't run this smooth in years.

I noticed a difference in my vaccuum gauge as well. Before I had problems it would pull a good 26 - 27 inches under strong decel. While I was having problems it wouldn't pull that much under strong decel. Have you noticed any decrease in your vaccuum?

No problems at all with vacuum. The same 26 or 27 as you describe.

Ira
 
I think it has to do with the Dash pod setting on the tune. I have the same symptoms from Engine one Till engine 3. Chances of me having a vacuum leak on all three of them are slim. I would ask Dalke. I belive the chip has a way of playing with the dashpod settings.
Mine drops once I reach a full stop. But when coasting I get a high idle.

Well I will certainly ask him about it. I have nothing to lose by asking. Maybe he can check the initial tune and see something.

Ira
 
1) A vacuum leak won't care if the car is coasting, in gear, out of gear, etc etc. It's not a vacuum leak.

2) It's not a bad IAC. The IAC functions perfectly normal. If an IAC is bad the idle will not fix itself by shifting in and out of gear.

3) While tune issues can cause high idle situations, that is not the case here either. It is normal for the motor to idle a little higher while coasting. My XR7 ALWAYS hung around 1100rpm until coming to a complete stop right from brand new. This is part of idle strategy. If it hangs higher than 1100rpm while coasting then you could benefit from some adjustment. Most likely it's NOT even a tune issue. Most hanging idle issues are related directly to the aftermarket TB not being set correctly. Adjusting EEC parameters to work around a TB that is not set right is not the best solution.

4) Ira clearly stated that - with consistency - the car idles down when shifted into neutral. This is a big huge fat light bulb. The problem is electronic. The car doesn't attempt to hit target idle speed until the shifter is moved.

From this I assumed that the neutral switch on the transmission must be malfunctioning but Ira changed that switch so we are assuming that is not it. The other component in this circuit is the clutch switch. If it were my car I'd be looking for a clutch switch.

If it isn't the clutch switch then I suspect the wiring in the car as this car was (if I understand correctly) changed from auto to 5spd by the previous owner.
 
1) A vacuum leak won't care if the car is coasting, in gear, out of gear, etc etc. It's not a vacuum leak.

Dave,

Just to be clear in my case it was a bad vacuum leak. My symptoms are not the same as Ira's but similar. In my case there were two very clear symptoms that had me scratching my head for a long time. One was the lack of idle down whenever the clutch was pressed in while switching gears or coming to a stop. It would eventually idle after XX seconds though. The other was it would never idle longer than about 45 seconds without stumbling very bad and trying to die. It fooled me for a long time because I could not hear a leak anywhere. I also noticed less vacuum on the gauge than usual. Jon
 
From this I assumed that the neutral switch on the transmission must be malfunctioning but Ira changed that switch so we are assuming that is not it. The other component in this circuit is the clutch switch. If it were my car I'd be looking for a clutch switch.

If it isn't the clutch switch then I suspect the wiring in the car as this car was (if I understand correctly) changed from auto to 5spd by the previous owner.
Great. Hey why not. It makes the most sense. What the hey. I'll check out the clutch switch and we shall see.

Just another little surprise. I swear, if it weren't for bad ju ju I wouldn't have any at all...... :(

Ira
 
Dave,

Just to be clear in my case it was a bad vacuum leak. My symptoms are not the same as Ira's but similar. In my case there were two very clear symptoms that had me scratching my head for a long time. One was the lack of idle down whenever the clutch was pressed in while switching gears or coming to a stop. It would eventually idle after XX seconds though. The other was it would never idle longer than about 45 seconds without stumbling very bad and trying to die. It fooled me for a long time because I could not hear a leak anywhere. I also noticed less vacuum on the gauge than usual. Jon

Yes your symptoms clearly point to a vacuum leak but Ira's symptoms are very different.
 
Great. Hey why not. It makes the most sense. What the hey. I'll check out the clutch switch and we shall see.

Just another little surprise. I swear, if it weren't for bad ju ju I wouldn't have any at all...... :(

Ira

Ira, If you have your old plug for the clutch switch from the auto circut, just use that to test it out. Would be much cheaper than a clutch switch and a lot easer to install. I had the same exact same problem with a 93 we converted from auto to manual. Never did figure it out. Drove me nuts after we replaced the iac and tps.
 
Ira, If you have your old plug for the clutch switch from the auto circut, just use that to test it out. Would be much cheaper than a clutch switch and a lot easer to install. I had the same exact same problem with a 93 we converted from auto to manual. Never did figure it out. Drove me nuts after we replaced the iac and tps.

Thanks for the idea, but I don't have the old parts. Transmission was swapped by the previous owner. Maybe I can find someone local that has one lying around that we can test it with though.

I wonder if Tony has an old one sitting around somewhere...?

Ira
 
Ira if u cant find one, come over here and we can gank whateve u need off of my car and test it out....and you'll get the see Millz House Of Car StufF,, if you come on sunday damon will be here and we can try to fig it out between he parts on all our cars
 
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Ira if u cant find one, come over here and we can gank whateve u need off of my car and test it out....and you'll get the see Millz House Of Car StufF,, if you come on sunday damon will be here and we can try to fig it out between he parts on all our cars

Thanks Miller, but I have to work this weekend and next so I couldn't bring the car around until after 5:30pm. Maybe I can get off the Sunday after that and we can play with it a little. One other thing I just noticed last night, now all of a sudden it almost feels as if the clutch pedal is getting "soft" at times. Maybe we need to bleed the system also.

Ira
 
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