: Misfire/hesitation

07-12-04, 01:50 AM
Hi everyone. Rather new to this forum.

I have a 96 STS with 94,000 miles. Bought the car in March 03 with 54,000 miles. The car recently in the Candian Rockies started to misfire, and hesitate while going up a hill. Replaced plugs with factory AC delco plugs and replaced wires. All the ignition coils seem to be alright. Disconnected fuel injectors as well as plug wires one at a time to see if one did not change the way the engine ran, but no change. Did compression tests on all cylinders, came up with about 165. My dad will run a SCOPE test to try figure which cylinder is misfirng and narrow the problem down to one cylinder. Any thoughts?

Thanks in advance.

07-12-04, 10:46 PM
Could be an injector. I would get an OEM injector and replace one at a time and see if still misses, If it does go to the next injector. You didn't mention if you're getting any codes that might help.

Does it start OK cold? Does it start OK after warming up and setting for awhile?

08-10-04, 06:17 PM
turned out to be a leaking intake manifold gasket. Nutin' else.

08-10-04, 09:25 PM
How did you find the leak? Thanks for the info.

08-31-04, 01:56 AM
Took it to a shop called Tune Tech. They had it for two weeks and charged about $300 to diagnose and fix the problem.