Fiero idles too high need reply ASAP

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Marine1

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I have an 84' Fiero and it idles too high, I have adjusted the idle stop screw, but it made no difference. I need advice and ASAP. It's preventing me from driving it. PM me if you have answers
 
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did you check for a vacuum leak, disconnected hose etc.?
 
Thank you guys, I will let you know soon if that was the problem
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what does that mean? You checked for disconnected hoses? You used carb spray to find leaks around intake etc.?
 
what is the vacuum reading?
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Marine1 said:
I'm getting too much vacuum. No leaks
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No, you have a vacuum leak. The leak is allowing more air to the engine. The engine compensates by adding more fuel. This increases RPM which may raise the vacuum level as it attempts to compensate.

You need to figure out where the engine is getting air from.
Try disconnecting one vacuum hose at a time off the throttle body and see if one of them causes the idle to drop. If not, try removing and cleaning (or replacing) the IAC (Idle Air Control) sensor. You could try disconnecting it first to see if it lowers idle, but generally it is difficult to tell as this sensor is reset when the vehicle is at 40 mph or higher.

NOTE: If you change the IAC, You will need to drive it at 40 mph in order for the ECU to reset it.
 
Last time it happened to me, it was the EGR connection pipe to the intake manifold on my V6, there was a crack in it.

You will always have a vacuum readings while the engine is running, even with a leak. The reading will not be affected by a leak, Its not like checking your tire pressure on a tire with a leak.
 
Oreif said:
No, you have a vacuum leak. The leak is allowing more air to the engine. The engine compensates by adding more fuel. This increases RPM which may raise the vacuum level as it attempts to compensate.

You need to figure out where the engine is getting air from.
Try disconnecting one vacuum hose at a time off the throttle body and see if one of them causes the idle to drop. If not, try removing and cleaning (or replacing) the IAC (Idle Air Control) sensor. You could try disconnecting it first to see if it lowers idle, but generally it is difficult to tell as this sensor is reset when the vehicle is at 40 mph or higher.

NOTE: If you change the IAC, You will need to drive it at 40 mph in order for the ECU to reset it.
Click to expand...

Thank you for making that clear, I will check tomorrow for the leak. I tried today to locate a leak today but the battery had died. I will get back to you with my findings
 
What Orief didn't mention, as you disconnect the lines, cap the ports they were attached to. As you disconnect, it opens that port as a leak. the cap that drops the idle is the line that is leaking. The MAP (manifold absolute pressure) sensor, right side of the filter housing, will stop the engine when disconnected. use a replacement hose to check that one.
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