89' Grand Prix Problem(Please help.)

[Dan789ca]

Well.. I hope this doesn't stump you car guys also.

I have an 89' Grand Prix Se. 3.1l V6


For about a month now it's been undriveable. The car starts with no problems and idles properly, but once you hit the gas the car chokes and either shutters and doesn't go or just stalles out.

Any ideas?

We have already ran the car into the computer's and we had 2 code violations come up and fixed them and alas it still didn't do anything.


the 2 Codes were: O2 sensor, Vacuum leak.


please im a College student who is running out of money!! Please give me some good suggestions

[GTP Dad]

Welcome to AF!!

Check the throttle position sensor to make sure it is working right and if you haven't already done so try unplugging the torque convertor solenoid on the top of the transmission. If the TCC solenoid is stuck it can cause the stalling you describe.

[maxwedge]

I'd also suggest checking the fuel pressure.

[richtazz]

I'm with Max, sounds like a fuel pressure issue to me too. Does it only die in gear, or does it die with throttle application in park/neutral too?

[Dan789ca]

It does it in park and Gear.

Fuel pump and everything is fine

[richtazz]

How did you determine the fuel pump is fine? What is the fuel pressure at the schrader valve on the rail?

[maxwedge]

Rich, just was going to ask the same thing! It's another "all the answers but the right ones"! Everything is fine???

[hallboy]

If you slowly apply the pedal does it rev or die?

How is your spark? Have you checked your plugs and or wires or even be sure they are firmly connected?

I just dropped $85 on a computer service check and the Goodyear place says "Take it to this electrical specialist we work with". Of course they want another $80+ just to check it again. I took it home checked all my plug wires and found one to be iffy. $25 bucks later it was the wires.

My point is it could be very simple. Don't pass up on any advise from these guys. Good luck.

[Dan789ca]

Yeah, all the plugs have been changed and wires were changed also. Still nothing. The idle will raise when you rev slowly but will not go past 2000rpm or it chokes and stales, unless you let go of the gas then it goes back down to the idling rpm.


We now have it at another shop putting it on there in-depth analsys machine.. 130$.. hope they come up with something

[Dan789ca]

Bump

[richtazz]

post your fuel pressure readings. We can't offer any other help until you do, as I still believe you have a fuel pressure problem.

[Dan789ca]

umm, I believe its 47psi.

[richtazz]

47 psi running, key on/engine off, or with/without fuel pressure regulator vacuum hooked up?

[Dan789ca]

key on my friend Hoses on

[richtazz]

ok, then next, take a reading with the car running and the regulator vacuum attached. the pressure should drop 3-7psi, no more. With the car still running disconeect and pinch/plug the vacuum hose (to prevent a vacuum leak) and the pressure should shoot up to near the original key on/engine off reading. If it fails either of these tests, the fuel pressure regulator is bad. If it passes these tests, you need to check spark and injector fire patterns as the vehicle begins to break up. A spark miss may indicate a cranks sensor or ignition module breaking down at higher RPM's. On the plugs and wires, what brands did you install?