Hi

I have 91 firebird V6 3.1L auto.
when I turn the key on, rpm reaches near 2,400 and stays until I engage transmission.
The same happens as I place the transmission on park mode after driving.

How can I solve this problem?

Does high rpm has something to do with big engine noise?

 

does the tach says 2000+. Does the engine sound like it is at 2000+? The factory tach's can be wrong, I've seen it before.

Define this big engine noise? Is it loud just from the RPM, or is there some abnormal sounding noise, like a knock?

 

Thank you for your response.
Yes, tach says 2000+.
Big noise comes from rpm. no knocking. Just very loud.

 

he meens does it sound like the engine is realy reving at 2000 rpm when you put it in gear... also when u do put it in gear does the car jolt forward? i would get this fixed before you drive the car or you are going to kill the tranny or rear end eventualy putting it into gear at that high of an rpm man... if you dont know alot id say you should just take it to a respectable mechanic and watch then find out the problem and watch what they do.

 

Then yea, the noise is not abnormal. Engines get louder as RPM increases.

What is the RPM in drive?

 

yes, car jolted forward when I put into gear.
I thought that happens because of bad U joint.

actually, my mechanic noticed this high rpm problem, but he could not fix it.
I am living in Korea. Mechanics here do not have much experience with this car.

I have not checked rpm at drive mode.

 

what is tranny?

 

Tranny= transmission

 

tranny is short for transmittion... find a good mechanic and have them fix it for you there has to be a good mechanic some ware there. dont keep driving it much if u have to put it in gear at 2400 rpm you are going to kill your transmittion or rear end eventually by doing that.

when u put it in gear does the car want to take off on its own with out you puching the gas also?

 

when I turn the key, rpm soars 2400.
Rpm drops under 1000 as I put it in gear(actually just passing through R mode).
Car jolt forward as i put it in gear, but does not take off.
Even after releasing the brake, car move forward very slowly.

 

So, car jot forwaard because of high rpm, not bad U Joint?

 

yes the car is jolting forword because it being put into gear at 2400 rpm and on a normal running engine it should only be running at 500-700 rpm when you put it into gear... but u will eventualy kill the u-joints in it by putting it into gear at that high of an rpm... this problem def needs to be fixed... does the check engine light come on while you are driving the car?

 

when I turn the key, rpm soars 2400.
Rpm drops under 1000 as I put it in gear(actually just passing through R mode).
Car jolt forward as i put it in gear, but does not take off.
Even after releasing the brake, car move forward very slowly.

No engine sign comes on( I am not sure engine sign system works on my car)

 

that is weird that the rpm drops back down when its put into gear and the car doesnt try to take off after you let off of the break even though it revs at 2400 rpm while in N..

 

car jolt forward only when I put it in D mode.

 

SOUNDS TO ME YOU MIGHT NEED TO RESET THE MINIMAL AIR CONTROL SO YOUR ECM CAN CONTROL YOUR IDLE AND I BELIVE YOU HAVE AN 91 2.8 YOU MAY ALSO HAVE TO ADJUST YOUR TPS VOLTAGE. JUST SIMPLY IT NEEDS A GOOD TUNE UP.

 

91 is the 3.1 V6.... First, the TPS voltage on these, unlike on a lot of other cars AND unlike the 2.8's, is nonadjustable. No way to set it on the 3.1 motors.

The idle speed is adjusted by a stop screw for the throttle blade. Look near the the throttle blade and find the screw that it rests against where it cannot possibly close anymore. Follow to the screw head...can you see the screw head, or is there a small plate covering it? If you can see the head, the idle has been adjusted manually...factory they put a plate in to prevent you from adjusting the idle.

If it HAS NOT been adjusted and the rpms are still high, see if the throttle blade is resting against it, or if it is open past it.

You might possibly have a vacuum leak, giving the motor unmetered airflow which is leaning it out and drastically raising your idle rpms. Checking the engine vacuum may be a good idea while you're at it. It's been a while since I've had my car but I believe you want between 18 and 22 hg's of vacuum at idle...although since your idle is so high that number will be much lower. Might want to have somebody put the car in gear, then pull the e-brake (if you can) enough that it won't move forward, and check the vacuum then at a normal idle without a vacuum-related accessory being used (such as normal brake...which is why I suggested e-brake use)

If none of this makes sense, that's because I'm drunk.

 

Thank you for your response.
I'll show your comment to my mechanic.
I hope your suggestion solve this problem.