Idle problem
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 36
Likes: 0
From: Stigtomta none
Idle problem
I have an acute problem needed to be solved before monday morning... The Idle is very high. I have done the idle setting procedure with the paperclip in the adld box and the tps-switch setting with the voltmeter. Have done all this but the Idle is still high, 1500-2000, have tried sprayin starter gas everywhere and no leaks... could it be that the engine is getting too much gas??
all suggestiond are welcome....
desperate :cry
all suggestiond are welcome....
desperate :cry
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Idle problem (Toggy)
Too much gas will typically flood it. I see in your profile that you have an 87. I've got a 92, but the principal should be the same. The car has an Idle Air Control valve. If the throttle blades are closed all the way the engine can't get enough air to run, so the IAC will open up and allow enough air to bypass the throttle blades to get the desired idle RPM.
If it idles too high it will close the IAC, if it idles too low it will open it up. With the car idling, try to unplug the IAC and see what happens, I bet the answer is NOTHING. Most cars will die if you unplug the IAC, I think yours SHOULD, but I'm not sure.
Also have you checked for vacuum leaks? You can go to your local parts store and purchase vacuum caps, unplug every vacuum line going to the intake and put a cap on the intake side. If everything is capped and it still idles high you either have a leak on the manifold you haven't found or it is in fact the IAC.
BTW, if you have a vacuum gauge you can put that on the manifold and see what you get, might be helpful it tracking down a vacuum leak.
If it idles too high it will close the IAC, if it idles too low it will open it up. With the car idling, try to unplug the IAC and see what happens, I bet the answer is NOTHING. Most cars will die if you unplug the IAC, I think yours SHOULD, but I'm not sure.
Also have you checked for vacuum leaks? You can go to your local parts store and purchase vacuum caps, unplug every vacuum line going to the intake and put a cap on the intake side. If everything is capped and it still idles high you either have a leak on the manifold you haven't found or it is in fact the IAC.
BTW, if you have a vacuum gauge you can put that on the manifold and see what you get, might be helpful it tracking down a vacuum leak.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Idle problem (Toggy)
How did you clean the TB? Were you having the trouble before or after you cleaned it? If it was working before you may well have messed up the IAC when cleaning. I don't think it takes well to cleaners.
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 36
Likes: 0
From: Stigtomta none
Re: Idle problem (Nathan Plemons)
I had the problem before cleaning.
cleaned it with carbcleaner as suggested on the forum... it was pretty dirty so a cleanup was neccesary anyway and would probably not have damaged the tb.
cleaned it with carbcleaner as suggested on the forum... it was pretty dirty so a cleanup was neccesary anyway and would probably not have damaged the tb.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Idle problem (Toggy)
I know on a Ford F-150 if you pull the plug on the IAC it will die. I'm not sure if ours work that way or not. I know mine didn't but I was having trouble with the IAC at the time.
If they weren't so damned expensive I would say to just replace it on GP.
Maybe if the rest of the TB was dirty then the IAC is too. See if you can very carefully remove it and see if it looks like it has any gunk on it. Don't press extend or retract it or you can ruin it, just try to clean it up, and of course clean out the hole it goes in.
If they weren't so damned expensive I would say to just replace it on GP.
Maybe if the rest of the TB was dirty then the IAC is too. See if you can very carefully remove it and see if it looks like it has any gunk on it. Don't press extend or retract it or you can ruin it, just try to clean it up, and of course clean out the hole it goes in.
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Burning Brakes
Joined: May 1999
Posts: 1,179
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From: waller texas
Cruise-In I Veteran
Re: Idle problem (nobodyunknown)
another forum guy said he found his t/b plates were not closing all the way since spring was to weak.were you able to get engine to idle down to 450 when setting the idle adjustment?with iac unplugged and turn the idle adjustment screw the idle should change.watch the tang on throttle lever.does it come in contact with idle stop screw?if not then the t/b plates not closing which can be the shaft for plates or the plates themselves are binding and not closing all the way.try moving the t/b plate shaft.can you feel movement up and down or side to side?if you do then the bushing or housing on t/b is wore out and probably the shaft or plates binding and not closing all the way.I have an 89 and sometimes the idle wants to stay a little high or takes time to come back down to idle.I do see some play in my t/b shaft which i suspect is causing this.I have seen posts where you can get t/b used on ebay for around 50 bucks.
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Re: Idle problem (Toggy)
Check your injector(s) resistance. They could be shorting out. Should be within 1 ohm of each other. Also, check the vacuum line to the fuel pressure regulator for fuel in the line. There shouldn't be any.
[Modified by ittlfly, 4:34 PM 8/31/2002]
[Modified by ittlfly, 4:34 PM 8/31/2002]
Burning Brakes
Joined: May 1999
Posts: 1,179
Likes: 0
From: waller texas
Cruise-In I Veteran
Re: Idle problem (KYVette90)
my 89 occasionally get a high idle problem and it usually is occompanied with the check engine light on with a code 36 which is maf relay burn off circuit.I think what I have is a wire getting ground somewhere or an open.I hate wiring with a passion but guess I will have to start checking all the wiring to maf and burn off relay.
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 36
Likes: 0
From: Stigtomta none
Re: Idle problem (vert2go89)
Thanx for all the help, i solved the problem temporarely by shortcircuit the a and b in the aldl box together with setting down the timing. The car runs bad, but the idle is at 900...