My new-to-me 89 GXL revs to 4000-4500 rpm at cold start.

I know a cold start activates the accelerated warm-up in an FC, but in all the other FCs I've owned (3) the warm-up is right at 3000 rpm and never higher.

Is this a sign of something wrong or trouble to come?

 

never really seen that before, next time i have a stock ecu car though its gonna get a pill in there to keep it at like 2k

 

How are your primary throttle plate gaps at idle?

 

Never had to do any throttle-related work so honestly I don't even know where to look. If you don't mind explaining a bit more to the resident idiot . . .

My idle is fine, if that helps any.

 

turn idle down? adjust throttle cable screws? i have no clue

 

If your idle is fine after warm-up, the gap's most likely good then...Hmmm...Are you sure your tach is working correctly?

 

Why not remove the Accelerated Wwarm-up all together. Mazda did this to warm up the pre-cat faster. High revs are not good on a cold motor.

 

that is true but also false...... it is to warm up everything. all cars have an accelerated idle when its cold to get it up to opperating temp faster. 3xxx isnt much for an engine like this. but its not good for it to be up as high as your is. seals and stuff havent expanted all the way. very bad things can happen if it continues to long. keep the accelorated warm up but fix it.

 

99% sure tach is fine. I know the accelerated warm-up is quite a bit higher than my other FCs because I compared them side-by-side and it sounds so much higher.

Right now, I tap the pedal immediately so it doesn't rev anyway. Just wondering if I should be worried about this difference.

Any ideas on how to fix it KingCobra?

Don't want to mess with an idle that is fine.

 

The fast idle is caused by the combination of the bac and the air bypass solenoid (aws) opening...not the throttle. I have no idea why yours rev's so high. I'd recommend removing the plug off the aws (air bypass solenoid) and seeing how much that drops your reving. On a series four, with the air bypass solenoid disabled, the cold start is in the 2300rpm range i.e. only the bac is opening instead to the two of them...less air being bypassed.

 

I'll try disabling the aws. BTW, this is a series 5 (1989).