My day just bought an 87 na, but it's got a few problems. the main problem is that when you start it cold it will idle at around 2300 rpm. Once the engine is warm the idle will fluctuate between 2300 and 2000 but it will never go any lower than that even when the engine is completely warm. This is getting really annoying so any help would be good.

 

Either a vacuum leak or a stuck throttle cable, or the throttle stop is set too high...

Also try adjusting the TPS and timing.

 

ok i can seem to find any kind of vaccum leak, but i did now notice that it is running really rich. The smell of gas is all over the car. like i said before this is causing the idle to stay very high and well never go lower than 2000 rpn.

 

did you try to adjust the idle, set the tps, check throttle cable tension, throttle plate positions, resistance of any solenoid valves. I'd suggest investing in a repair manual for these kinda of thing, they have troubleshooting sections that have all this right in them, even quicker than looking on here.

 

ok everything with the idle is good. it is set where always has been set and even when i adjust it doesn't do anything. and i also already looked in the manual and i found nothing. i just don't think it has to do with the idle because it is running very rich.

 

did or did you not you check the solenoid valves on the Upper Intake Manifold for resistance and 12 volt click?

 

ok where r those solenoid valves? I'm assuming that they are the colored valves that are on the driver side of the motor. and how do i fix it if that it is the problem?

 

no check the Bypass Air Control Solenoid Valve's resistance(shoul dbe 10.7 - 12.3ohms) and if it clicks when +12V is applied to it's terminlas, which is on the rightside of your dynamic chamber i think.

Then check the air bypass solenoid valve(this is called the accelerated warm-up system solenoid valve on S5's) for voltage when it's female plug isbridgeed with a 2k ohm resistor, it's only supposed to have 12 volts after 17 seconds on the engine running, no voltage befire that. Also check the resistance of the valve through it's (should be 9.2 - 11.3ohms for NA) This vavle is right by the BAC.

Check the relay for the air bypass as well.