'88 High idle

[RredFJ40]

I don't have my FSM yet and the Haynes doesn't help.

My 88 idles really high in Park, like 1100 to 1200. When it goes into drive it comes down to around 850. This might be part of the reason I'm getting 11-12MPG. Where do I turn this down? Or is there a malfunction that is causing this?

 

[azaussie]

I don't have my FSM yet and the Haynes doesn't help.

My 88 idles really high in Park, like 1100 to 1200. When it goes into drive it comes down to around 850. This might be part of the reason I'm getting 11-12MPG. Where do I turn this down? Or is there a malfunction that is causing this?

My 88 idles very similar to yours-- 1100-1200 in park and neutral and drops down to about 800 or so when in gear. I think the high revs are killing my city MPG as around town I am only getting 10MPG while on the highway I get better than 16 MPG. Very interestd in the answers to your question.

 

[Aseif007]

Does the idle bounce when you come to a stop? Have you tested for vac leaks? (with some carb cleaner) If your timing is correct, and your TPS and Dash Pot are adjusted correctly, and you throttle cable is adjusted correctly, and you are sure the AC idle up is not constantly on, you can adjust the "golden" screw on the throttle body and that will increase or decrease the idle. But do this as a last resort and after you have checked all of the other things mentioned above first.

 

[billmc]

First things I'd do would be to make sure the accelrator and throttle cables are not binding. If you warm it up to normal temp in the morning before driving it anywhere, does it idle that high? The next thing I'd check is that the TPS is not gummed up and sticking, preventing it from returning to the idle position. Like the previous poster said, I wouldn't start adjusting the big screw until you can say categorically that everything else is correct.

Bill

 

[azaussie]

First things I'd do would be to make sure the accelrator and throttle cables are not binding. If you warm it up to normal temp in the morning before driving it anywhere, does it idle that high? The next thing I'd check is that the TPS is not gummed up and sticking, preventing it from returning to the idle position. Like the previous poster said, I wouldn't start adjusting the big screw until you can say categorically that everything else is correct.

Bill

If the TPS is gummed up what shold I use to clean it?

 

[RredFJ40]

Where is the dash pot? On the ECU? and how do I adjust it. Like I said, I don't think this is outlined in the Haynes anywhere, at least I couldn't find it.

 

[jwest]

Dirty throttle body.

.

 

[RredFJ40]

Cleaned it up with zero effect. Next!

 

[RredFJ40]

What I don't want to here is that my O2 sensors are bad, at $150 a piece, that's gonna hurt.

 

[jwest]

Cleaned it up with zero effect. Next!

So, wth didn't you say that from the outset?

People are trying to help ya. You think you're giving out free kisses at a kissing booth?

 

[RredFJ40]

I like free kisses. My mistake, sorry for the sarcasm. Guess I need to use smilies more

 

[Aseif007]

Have you checked the throttle cable? If not turn on the car and with your hand twist the throttle on the throttle body closed to see if that reduces your idle. If it does, your accelerator cable may be too tight. Also check for free movement of the cable when the pedal is pressed. Have you checked the timing? Do this, you should be 7 degrees BTDC with the jumper wire shorting out TE1 and E1 under the diagnosis box located on the passenger side of the firewall under the hood. The hayes should be adequate for this. Have you checked for a vacume leak? If not use a can of carb cleaner and spray on the intake tubes and the manifolds, and if your engine idles up then down after you spray the carb cleaner then you may have a leak. The TPS may seem fine but without using an ohmmeter to test it there is no way of knowing for sure. Does the idle raise when you turn on the A/C? Also, do you hear the ISC (idle speed control) clicking when you first give the car power? There are some things I would check.

 

[azaussie]

What rpm's should a 62 idle at?

 

[billmc]

Cleaned it up with zero effect. Next!

How did you clean it? And if you don't have the FSM how F do you know it's good and how do you know you have it adjusted properly?

Bill

 

[peepers]

How did you clean it? And if you don't have the FSM how F do you know it's good and how do you know you have it adjusted properly?

Bill

... you should really get the FSM, factory service manual. look up the TPS. in there, you will find how to test it and set it to within spec.

i need to do this myself. i have your same issues.

also, like stated a ton of times... check for vacuum leaks with carb cleaner. spray your hoses, if the rpms go up, preplace the hose you just sprayed.

 

[walker]

This solved it for me

R&R Throttle body ,cleaned and waxed over cold start valve and egr port..I had my mechanic do it. Idles perfect .

 

[archie]

What I don't want to here is that my O2 sensors are bad, at $150 a piece, that's gonna hurt.

You should get check engine codes for bad O2 sensors and I know of a place that sells em for about 65/piece with good results on my 62. PM me if you need the O2 sensor supplier.

 

[Bryan062087]

try turning ur ac off

 

[azaussie]

My 88 idles very similar to yours-- 1100-1200 in park and neutral and drops down to about 800 or so when in gear. I think the high revs are killing my city MPG as around town I am only getting 10MPG while on the highway I get better than 16 MPG. Very interestd in the answers to your question.

My truck appears to have cured its high idle by itself (which is a bit scary). Now revs at 600 - 700 when in gear and 800 - 900 when in park.

 

[CTiger]

I have the same high idle problem in my 88. Had my mechanic look at it, and I think all he did was make sure the timing was correct, and he probably went ahead and adjusted the big screw after that. The problem is that when he adjusted the idle downward, the truck got very sluggish when being driven, so he had to put the idle back up for it to be driveable. What gives? Btw, when I turn on the AC, the idle doesn't go up. thanks and sorry in advance if this counts as a hi-jack