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GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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Chevrolet Silverado 1500: I have an 05 chevy truck 4.3l The

Customer Question

I have an 05 chevy truck 4.3l The engine turns over, but will not start. Compression on all cylinders 140 to 150, plugs new, wires, rotor and cap good, icm tested good at autozone, coil new, have spark at plugs, when cranking if crank for along time (15sec or so) sounds like weakly trying to start like the timing is retarded. Truck was running fine prior to this issue.
Submitted: 2 years ago.
Category: Chevy
Expert:  Virtual Wrench replied 2 years ago.

Have you checked the fuel pressure with a gauge?
Customer: replied 2 years ago.

Yes fuel pressure 50psi and holds well when turn key off. Truck will not hit on starting fluid

Expert:  Virtual Wrench replied 2 years ago.

Well, if it wont hit on starting fluid and you are SURE it has spark at the plugs that leaves a real good possibility the cat convertor is plugged. Try removing the upstream O2 sensor before the cat and see if it starts..let me know please..
Customer: replied 2 years ago.

I think I am missing a starting sequence input, what controls or influences the startup ignition timing. This is the third time this no start condition has occurred in 2 weeks. After the third time it has refused to start. On the 2 prior times once it started the next day the other a few hours later. I did not do anything to the truck the first and second time but check for codes(there were none), confirm fuel pressure, and confirm spark. The truck just started when it was ready. I will check the cat and let you know in about 45min., but I suspect an electrical issue that I am missing.

Expert:  Virtual Wrench replied 2 years ago.

But if it has all the things you first posted, that is all an engine needs to run, except a way for the exhaust to get out..we sure replace a LOT of them for being restricted....let me know later when you plull the O2
Customer: replied 2 years ago.

Ok, pulled o2 on both banks upstream of converter still no start

Expert:  Virtual Wrench replied 2 years ago.
Everything seems to defy logic here if it has fuel, spark, timing, comppresion and air because thats all an engine needs to run. The only other thing i can think of is maybe the plugs are fuel fouled from so much cranking trying to start it.