i used to have an unstable idle but recently did a motor swap and the idle issue is still their. The mechanic said it could possibly be an issue with a solenoid due to haveing done the motor swap and the idle issue shouldnt be from the motor but im not really familiar with the mechanics. any feedback would be appreciated......Also since the swap the motor has had an issue with flooding which i know is something the FC's used to have an issue with, not sure if that relevant or not.....thanks..

 

What do you consider "unstable" idle? It would be great to get a few more details.

 

its not steady it constantly goes up and down, and lets say if im at a red light and i tap the gas the car will nearly stall and actually will sometimes, when driveing you actually have to tap the gas a lot to avoid stalling.....before the swap i would just adjust the bolt on the throttle to compensate but that was just a tempory fix...

 

When you swapped the engine did you keep the rest of your components the same? ie. UIM, ACV, throttle body etc?

 

im not sure which components were kept the same, the ones i know for sure was the throttle body and the ecu, the rest were canabalized from which ever parts were in better shape

 

If your throttle body was kept the same, have you considered checking your TPS voltages? Your symptoms sound alot like out of range voltages which can actually cause a drop in RPM when the throttle is tapped. Worth a shot.

 

is there a check engine light? If so you might wanna pull the engine code and see what code it has. As rossc stated, check the voltage of the TPS (when the engines warm) and make sure its to spec. If its not that, check the obvious like the connector to the TPS is connected, MAS is attached to a vacuum line, vacuum leak, etc...

good luck

 

do you have a boost gauge, what do you pull on vac at idle, sounds like tps voltage, vac leak or a mix of both.. I had the same problem when i first got my fd, checked tps voltage and everything was fine, ended up being a vac leak ( a couple of hoses were off and had a damaged lim gasket). Try to hold the car at idle and listen for hissin.

 

my psi is a lil below 0 @ idle, but how do you check for tps voltage?

 

sorry you should be pullin alot under 0 at idle not a little, Does your boost gauge show vac? if so then you have a horrible vac leak and thats your problem..