1998 Chevy Silverado Timing issue

1998 CHEVROLET SILVERADO
163,000 MILES • V8 • 2WD • AUTOMATIC
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IAMI2760
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This truck has been fantastic, no trouble at all for many years. She's showing her age finally: Last year she misfired, code was #5 cylinder misfire. Replaced plug, no luck. Replaced plug wires, no luck. Replaced the injector on #5, no luck. Replaced fuel pressure regulator, no luck. Same #5 misfire code and rough idle. Finally I started smelling anti-freeze from the exhaust, so I knew it must be the head gasket. I replaced the head gasket, was sure it was set to TDC before pulling the distributor, and marked it accordingly. On reassembly, the #5 cylinder misfire code is not there, but truck runs VERY rough, and has two codes: 301 #1 plug misfire, and 1345. The timing some how is off, and I cannot dial in the timing no matter how much I turn the distributor. There is no vacuum leaks that I could see, and I looked very close. Any ideas on a direction to go? I'm beating my head against the wall now that it runs worse then before the head gasket change.


I've checked what you have suggested, air escaped the #1 plug, and the rotor pointed to the #1 point. I got to thinking though, when I replaced the intake manifold, the gasket kit came with the two lower intake manifold gaskets, but there was nothing to cover the front and back portions of the lower intake manifold. I remembered scraping/cleaning away material from these areas when breaking the heads down, would I need to apply a liquid gasket again? And would this induce a sort of vacuum leak?
May 3, 2009 at 8:28 PM
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MMPRINCE4000
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Remove plugs, rotate engine by hand (ratchet on balancer), place finger over #1 spark plug hole, air should escape (compression). Rotate until timing mark on balancer is aligned.
Check dist. rotor, should be pointing at #1 plug wire, if not, remove dist. and rotate until it does.

If above check out, then run a compression test to see if headgasket problem or valve issue.
May 4, 2009 at 7:21 AM