Stumble, hesitation on a '97 SC2

[alrich]

My 1997 Saturn SC2 hesitates when the temp guage reaches around 1/2 way mark in stop and go traffic. It will accelerate from a stop and around 1900-2000 rpm hesitate for a second and then keep on going. New plug wires, spark plugs around 12,000 miles. estc sensor changed around 5 years old, cleaned egr valve-not that dirty. The car has 133,000 miles on it. Any suggestions what causes that? No service lights have come on. Anybody else have this problem? Thanks for any help
Al Rich
Charlotte, N.C.

[MikeH]

Make sure your ECTS is one with a brass tip inside. The ones with plastic don't last long.

[plastic torpedo]

Dirty EGR will cause your engine to run lean and stumble. Disconnect the EGR and see if it runs better, it will if EGR is the problem.

[cheapybob]

Originally Posted by alrich

My 1997 Saturn SC2 hesitates when the temp guage reaches around 1/2 way mark in stop and go traffic. It will accelerate from a stop and around 1900-2000 rpm hesitate for a second and then keep on going. New plug wires, spark plugs around 12,000 miles. estc sensor changed around 5 years old, cleaned egr valve-not that dirty. The car has 133,000 miles on it. Any suggestions what causes that? No service lights have come on. Anybody else have this problem? Thanks for any help
Al Rich
Charlotte, N.C.

At night, in the dark, open the hood with it running and rev it to 2000. See if you see any sparks near the wires or coil towers. Also inspect the wires for burn spots and make sure they connect well. On my SC2, there were 2 wires too close to each other and it was arcing causing similar hesitation. Also, put an VOM on the plug wires and check resistance. Look for less than 1000 ohms on each or replace.

[plastic torpedo]

Originally Posted by cheapybob

At night, in the dark, open the hood with it running and rev it to 2000. See if you see any sparks near the wires or coil towers.

Yes, by the way, I have seen horrible things happen due to bad spark plug wires! And this test definitely works. It would help if somebody could start the car while you're looking under the hood at night.