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Old 10-19-2009, 02:42 AM   #1
HookNBook81
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Having problem with My 85 C-30 Need help...

Ok , heres the story , got the truck about a month ago 350 chevy HD 4 bolt block 30 over , quadrajet carb is stock, stock everything else as well, timing was way off..
I set it 8 degrees btdc, ran Ok from the original setting of 4 btdc...

I recently rebuilt the carb as well I was having a stalling problem when I stopped which turned out to be a combo of the carb and a leaky return line on the fuel pump...but I put it back at 4 btdc for some reason ,cant remember why..lol


swapped in new plugs about a week ago, It ran ok.

I pulled the plugs and # 2 was oily , I mean caked in oil...hmmn I thought to myself probably rings

I readvanced the timing to 8 btdc today it ran good , turns over fast and everything , no over heating at all...a few miles into my trip it started acting like it was missing and lack some power
I get home and pulled the # 2 plug again and its clean as a whistle and matches the rest with a cocoa brown color , ...wtf is goin on here ..lol

Before all this I hooked my timing light to each individual wire and all where firing great except # 2 which was intermittent like a misfire ...

the vacuum can on the dizzy is hooked to manifold vacuum and the carb mix screws are 3 1/8 turns out rpm is 750 ...

I assume Im having a random misfire from a bad plug wire on # 2 and thats what caused the plug to load up with oil/gas.... any things I can check otherwise?...

it still doesnt explain why it started runnin like butt again though when the plug was firing..

Last edited by HookNBook81; 10-19-2009 at 02:52 AM.
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Old 10-19-2009, 08:18 PM   #2
rfmaster
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Re: Having problem with My 85 C-30 Need help...

You may have intake manifold leak which sucks in oil from lifter valley. Rare, but it does happen. Another possibility is a worn intake valve guide and a tired PC seal. Both will introduce plenty of oil into combustion chamber.

Before ripping intake manifold of - check cylinder compression or better perform cylinder leak down test. This way you can be certain that you do not have worn rings.

//RF
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