Revving issue...

[AForceOneRacing]

Hi,

My 94 Integra GSR is having some issues. It is the last week of the racing season for this car and I am already solidly 2nd in points (I could skip the event) with no hope of winning the championship.

The car is idling strange. Upon starting it ramps to 3500 RPM in a hurry and then drops to 1000 RPM. It then goes into a goofy idle where it jumps up to 2500 and then to 1000. It repeats this until you drive it. It sounds horrible.

What can cause this? It doesn't have an impact on its drivability (short of maybe a small power loss) but it is aggravating as heck.

Any ideas?

 

[red98teg]

o2 sensors? throwing any coodes? straight pipe or cat? spark plugs good? i really couldnt tell you too much but those are the things i would check...

 

[dylan si]

Vaccum leak? Take a bottle of carb cleaner and spray the engine bay while the car is running and see if the idle spikes even more, if so vaccum leak

 

[AForceOneRacing]

o2 sensors? throwing any coodes? straight pipe or cat? spark plugs good? i really couldnt tell you too much but those are the things i would check...

Cat, spark plugs are ok.

My fear is that it is the head gasket. There have been other problems on this car (radiators going out, overheating) that are tending me to lead toward the head gasket as the likely cause.

I have not checked for codes.

The dealer said it was either a bubble in the radiator (not possible), a coolant temp sensor, or a head gasket.

 

[dc2b18]

is it leaking water??

 

[skoodles]

if its a bubble in the radiator. it could send air past the coolant sensor and air through the IACV wich would make it run like doo doo. take the radiator cap off and let the car idle and just keep adding water in it turn the heater on too if you have it still. run it till both upper and lower hoses get to the same temp. then you know the thermostat has opened. that could cause it.