Thomas Moore
Newbie
Hi all. I need some help. I have a 1993 GMC Sierra 1500 SLE 5.7 Automatic with316k on the clock. The truck was missing but ran pretty good and reliably. An experienced mechanic friend offered to help me replace my leaking radiator, do a tune up and clean up the grease and oil from leaking valve covers as well as replace the gaskets. One that day we did the following:
I took the cap off and let it dry for a couple days but it didn’t help.
I then replaced the cap and rotor but that did nothing.
I drove back down to my friend and tested the timing. We determined that the timing chain does have slack and I will be replacing it but in my head this shouldn’t be the cause of the problem because it would not explain being so much worse after the tune up.
I used the timing gun to see if the coil was cutting out, testing each wire. Cylinder 1 does cut out, but the rest seem not to. My thought was if the coil is going bad it would affect all cylinders the same.
After some research we decided to replace the electronic spark control module in the distributor but again it did nothing.
I am at a complete loss at this point. Anyone have any suggestions?
Thanks so much,
Tom
- Cleaned the entire top side of engine with simple green and water from garden hose with fairly low pressure.
- Replaced valve cover gaskets.
- Replaced all spark plugs and spark plug wires.
- Replaced radiator, hoses, and thermostat.
- Cleaned up wiring (bare sections, bad routing, etc)
- Replaced cracked vacuum lines.
- Replace PCV valve.
I took the cap off and let it dry for a couple days but it didn’t help.
I then replaced the cap and rotor but that did nothing.
I drove back down to my friend and tested the timing. We determined that the timing chain does have slack and I will be replacing it but in my head this shouldn’t be the cause of the problem because it would not explain being so much worse after the tune up.
I used the timing gun to see if the coil was cutting out, testing each wire. Cylinder 1 does cut out, but the rest seem not to. My thought was if the coil is going bad it would affect all cylinders the same.
After some research we decided to replace the electronic spark control module in the distributor but again it did nothing.
I am at a complete loss at this point. Anyone have any suggestions?
Thanks so much,
Tom