Hello,

I have a pristine 1990 Pontiac Grand Prix with all the bells and whistles (HUD, ABS,Turbo, etc.). Recently, I was accelerating to get on a freeway when suddenly, at 3000 RPM, the car simply stopped. Now, I rarely have to go over 3000 RPM for anything, however, I nearly got hit in the butt by the guy behind me, who instantly relayed to me how happy he was with my car'* performance with a series of Hand Signals...! I know the car has a rev limiter for Park and Neutral, but it is not supposed to be engaged in drive (I thought). So.......where is this thing and how do I fix it. Many Thanks, Pat

Did it rev limit by jumping up and down in RPM, or did it cut out? A cut out might have been a electrical problem such as loose battery cable.

Thank you for replying Dan...No, it stops at 3000 but does not shut off or stall. It simply drops out. The indication is the same as when you sit in park, as on a Calif. Smog test, and rev the engine in park too high, and the needle "bounces" in and out as the engine revs to 3000K and then falls off; then repeats the problem with each new rev. I would look for a governor, but I do not know how this rev limiter works, or perhaps its part of the computer system? Don't know,,,that'* why I am here. I appreciate any ideas. Thanks..Pat

It'* part of the computer. Odd, I would check the nutral safety switch. Can you start in gear?

I was thinking neutral safety switch too.

Do you have an ASC/Mclaren Turbo Grand Prix?

No, it will not start in gear. As stated, it seems to have all the same indications that it is doing the same thing that it is designed to do in Park or Neutral with regard to over reving, but it does it in drive. As a computer programmer, I do not understand how the computer could suddenly start sending a wrong signal. I could understand it not working at all, but never sometimes. Things like this (I feel) are limited to failures of sensors feeding inaccurate information to the computer or mechanical devices that malfunction, but if you feel confident that it is the computer, I will get one. Let me know your thoughts. Thanks again for your time and input....Pat

PS: I just went out and double checked it to be sure. The car will not crank unless it is in Park or Neutral.

Take the car out and drive about 10mph... then put it in neutral and try to rev the engine to 5500. If it stops at 3k, the computer'* probably not getting a speed signal.

Thank you Jon...I will try that right now...but I am confused. I thought that the car should NOT be able to rev over 3000 when it is in neutral, and so I thought that the this would be an expected result....unless the sensor is controlled by the speed indicator rather than the transmission function selection. I guess it'* bad for me to "presume" since I do not know (and that'* why I do not have the answer and I need you, right.... In any event, I will do that right now...THANK you for the advice. I will post here within 30 minutes....Pat

Im my Turbo Grand Prix, As long as the car is going over ~5mph, you can put it in neutral and rev all the way. I have a diagram of the ecm harness in my garage. If it doesn't work then I can tell you what pin to test for continuity.

Wow, Jon (et al)

Some very interesting results. In Park and Neutral, the rev limiter works as it is supposed to. At under 10 MPH...same thing, rev limiter is engaged. Get This; in Manual 1 OVER 10 MPH, the revs will go smoothly to 5K with no problem...BUT in Manual 2 or 3 or 4(Normal Drive mode), the rev limiter kicks in and stops the car from going over 3K even when the car speed is over 10 mph. I am sure that this points to something definite, but I am not sure what. Perhaps there is some kind of speed sensor that is sending inaccurate (or missing) info to the computer? Or ??? Then why does it work correctly in Man1? What the heck, I'm just guessing. What do you think? Thanks, Pat