87 T2 High revs?
 

Hey guys,
Got a weird problem here,

When I turn on the car, it just shoots up to 3.5 sometimes 4k. It sometimes drop back to normal after some highway driving only.

This happened after my TPS was changed and adjusted.

Prior to that, the car would just not want to go past 3.5 if I mash the gas; the only way before to pass the limit was it to ease on it and never mash it once passed that.

I was advised it might be the harness or some kind of electrically thing; but personally I think it is a shutter being stuck open.

Does anyone have any idea what this could be or suggestions that I should try?

Thanks

Well, it sort of depends.

The 3K startup is a factory function programmed into the ECU to light off the cats quickly. When started the car jumps to 3K for about 20 seconds, then should drop down to 1.5K, then slowly decrease to idle speed as the car warms up.

If that is what is happening, then your car is operating as it should. You can start the car in gear (clutch pressed of course) to disable it.

It's probably now working because of the proper TPS adjustment.

Thanks for the reply,

Awh I also forgot to state that it revs that high just in neutral and when changing gears.

For example crusining down the highway in 4th at say 2k, then when I want to shift to 5th,

clutch in, car revs highs. Also, the car would say "drive" by itself. I also got a new throttle cable from 401 mazda.

Don't waste money on a cable, it's not your problem. To me it sounds normal, what Aaron said. After the car reaches operating temp do you still have the same problem?

Yes the problem does still persist at operating temperatures. That's what is bothering so I do not know

Check the screw on the throttle body that adjusts the idle. Try to turn it down and see if that fixes it.

Thanks for the reply

http://fc3spro.com/TECH/HOWTO/TPS/tset2.jpg

This one here correct?

I went for a drive today as it was nice out today.


Driving nice, as then as stated before it passed 3k it okay. Once it does the phase when changing gears the car would jump and stay at 4k if clutch is in.

If you can find a picture of some sort

the engine wont generally rev that high unless its taking in air from a massive vacuum leak or the throttle is open. Try disconnecting the throttle cable entirely and see if the engine still revs on its own when you start it up

If the car has cruise control then the cable can hang up and make the Throttle body go to another "setting" as compared to the Throttle cable.
There is more than just the cables that you should be looking at.
Take the intake elbow off and actually look into the Throttle body and open/close it without the cable on it to see if it "hangs up".
My linkage on my TB did that and the car went to SIX K..in a freakin parking lot..over speed bumps..

I've seen a lot of 2nd gen throttle bodies over the last few years that have sticking secondary throttle plates. Thoroughly degrease the throttle body then soak it in penetrating lube. Work all the shafts back and forth until everything moves freely. Then hose down with brake cleaner to remove excess lube.

^ Good advice. No one works the shaft like Aaron.

Yeah I will give it try when it gets back warmer. I thought it left but winter isn't going away that fast