Engine stalls when slowing down from

MATTSTER88

MEMBER
1993 PONTIAC GRAND AM
4 CYL
FWD
AUTOMATIC
67,000 MILES

Here is the problem - after I have driven for a while (30 - 40 minutes) at a higher speed (60-70 mph), I will slow down and attempt to stop. However, when I hit about 20 mph my engine will begin to run really rough. As I slow down more, it runs rougher and rougher and as I come to a stop it will die. If I attempt to go faster and give it more gas, it will not speed up and continue to run rough. It will start up fine, but it will occasionally stall as soon as I put it in gear (immediately after the initial stall - it always starts fine when cold), although it has always taken off and worked just fine eventually.

This has never happened when I drive 10-15 miles around town, only after driving a more significant distance. Any ideas? Thanks so much in advance!

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

When this happens, does it feel as though the engine and transmission are not disengaging? Has the check engine light turned on or flashed during this problem?

Since it is only happening after driving at highway speeds, I question if it is related to the converter clutch lockup solenoid. If it doesn't release, it would be like trying to stop a vehicle with a manual transmission without pressing the clutch.

Here is what I suggest. First, we need to check for diagnostic trouble codes which may lead us in the right direction. This vehicle has an OBD 1 system which doesn't require a scan tool to retrieve codes. All that is needed is a short jumper wire or even a paper clip. Follow the directions in the following link and let me know if and what codes are found.

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Also, I attached the diagnostics to test the solenoid specific to your vehicle.

Let me know if this helps or if you have other questions.

Take care,

Joe

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