90 Cutlass Suprm runs like crap when warm

90 Cutlass sprm 3.1 (I think) runs like crap when I drive somewhere far enough to make the car heat all the way up, then shut if off for 30 to 90 minutes. Start it back up and it barely runs. I have to consistently pump the gas to keep it running. After about 2 min. of keeping it runing it runs fine. My guess is something ignition or coolant temp sensor. I don't know anything about these motors.

Any info is greatly appreciated

This problem is hard to search for and I read through a bunch of posts without finding a similar problem. Hope this isn't something that gets posted all the time.

90 Cutlass sprm 3.1 (I think) runs like crap when I drive somewhere far enough to make the car heat all the way up, then shut if off for 30 to 90 minutes. Start it back up and it barely runs. I have to consistently pump the gas to keep it running. After about 2 min. of keeping it runing it runs fine. My guess is something ignition or coolant temp sensor. I don't know anything about these motors.

Any info is greatly appreciated

This problem is hard to search for and I read through a bunch of posts without finding a similar problem. Hope this isn't something that gets posted all the time.


check for trouble codes go to advance or auto zone free scan, may be crank position sensor.

I took it to an autozone and the bastard told me he couldn't do it because their scanner didn't do cars under 96. I told him to pull a scanner off the wall to do it, but he wasn't cooperating. I'll have to try a different autozone.

These carsd are EASY to scan for codes on your own. Here's how.
1. Get a paper clip.

2. Bend the clip into a U shape with the prongs about 1/8 inch apart.

3. Find the diagnostic connector, under the dash.

4. Stick the clip in the two right side pins in the connector on the upper row only. This will connect these two pins.

5. While these two are connected, switch the ignition on, but do not start the engine.

6. The check engine light will flash twice, quickly. This flash will be repeated twice more.
This is a code 11, and tells you the ECM is in its diagnostic mode.
If there are any other codes, they will be displayed after the code 11.

You must count the flashes to determine what the code is. For example, a code "34" is a series of three flashes followed by four more flashes.

Each code is repeated three times before the next code is displayed.
Try this and let us know what codes are displayed.

Or go here for more info:
http://www.troublecodes.net/GM/

Check and clean the EGR valve. The key here is the fact that it runs like crap when it is warm. That is when the EGR valve usually starts to work and can cause issues. The valve itself may be bad but it could be the passageways into the plenum are clogged with carbon and need cleaned. If the valve is bad get one from a wrecking yard, they are very expensive.

EGR might be right on. I pulled the codes last night

32 The ECM opens each EGR control valve during deceleration and monitors the change in manifold vacuum. The code sets when the change in manifold vacuum is outside the normal range.

33 MAP sensor voltage was too high for 4.8 seconds when throttle angle was less than 2%

35 MAP sensor voltage was too low for 1 second when engine speed was under 600 RPM, or MAP sensor voltage was too low for 1 second when engine speed was over 600 RPM and throttle angle was above 20%.

Big Thanks to everyone that is helping out!!!