High idle problem with 5.0L HO engine

I have a 91 TBird with the 5.0L HO engine and AOD. It suddenly developed = a high idle. I checked the linkage, nothing is binding or hanging up. I = even unhooked all the cables from the throttle body, made sure it was = closed and started it. High idle.

It idles about 2000 rpm. At first it would only idle high a few seconds = when you first started it up. Now it idles high, ALL the time.

I pulled apart a few wiring connectors and all the contacts look clean = on the idle air solenoid, TPS and maf sensor.

What could be wrong and how should I check it?

Dan S

Reply to
Dan
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It idles about 2000 rpm. At first it would only idle high a few seconds when you first started it up. Now it idles high, ALL the time.

I pulled apart a few wiring connectors and all the contacts look clean on the idle air solenoid, TPS and maf sensor.

What could be wrong and how should I check it?

Dan S

Reply to
Bob Manly

It idles about 2000 rpm. At first it would only idle high a few seconds when you first started it up. Now it idles high, ALL the time.

I pulled apart a few wiring connectors and all the contacts look clean on the idle air solenoid, TPS and maf sensor.

What could be wrong and how should I check it?

What happens when you pull the plug on the IAC motor/solenoid? Report back on this... also, it could be dirt or debris holding the throttle butterfly open a crack.

Rob

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Reply to
Trainfan1

It idles about 2000 rpm. At first it would only idle high a few seconds when you first started it up. Now it idles high, ALL the time.

I pulled apart a few wiring connectors and all the contacts look clean on the idle air solenoid, TPS and maf sensor.

What could be wrong and how should I check it?

Dan S

Reply to
Thomas Moats

Reply to
Marky

By IAC motor / solenoid, do you mean the air conditioning compressor? = The air doesn't work so compressor isn't kicking in.

Reply to
Dan

"Dan" wrote

Nope. Idle Air Control valve. Diagonal thingy on the side of the throttle body.

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Reply to
MasterBlaster

Have you checked the coolant temperature sensor and it's electrical contacts?

Reply to
Childfree Scott

No I haven't checked the sensor or it wires yet. I'll have to look = around for it. This is a " new to me car".

I did what the other fellow asked and unplugged the IAC while it was = running. It made zero, zip, nada, no difference. I kept plugging and unplugging it and it never did a thing for the idle.

Does this mean it is defective or just needs to be taken apart and = cleaned?

It looks pretty easy to take off...

Reply to
Dan

I did what the other fellow asked and unplugged the IAC while it was running. It made zero, zip, nada, no difference. I kept plugging and unplugging it and it never did a thing for the idle.

Does this mean it is defective or just needs to be taken apart and cleaned?

It looks pretty easy to take off...

============================ Nothing wrong with trying to clean it first. It is easy to take off, and is a very common problem on Fords of all ages.

Reply to
Scott M

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