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5.7 SBC Surging on acceleration and under load in gear only.

11896 Views 60 Replies 5 Participants Last post by  junktrucker
Ok, so I am new here, but I am not new to this truck. I have a 1985 Chevy Scottsdale C30. This thing is a pig, and acts accordingly. I've been all over this truck since I got it a year ago and my head has been itching over it so much that I've developed a balled spot. That said, the title explains it. I can't get this thing to surge here in the driveway, at all... period. and the only way I can test my "fixes" is to drive outa my subdivision to the local stretch and romp on her, which is where she decides to conform to her true nature; a no good, fumbling, bucking, squealing pig that wants to do anything BUT what I ask from her. Here's what I've done so far.
-New Mechanical fuel pump
-Cleaned out the gas tank
-Rebuilt Carburetor
-plug wires, and plugs
-oil change
-checked timing.... over and over again.
**cant find a true VIN CODE M Emmisions label for this truck.
-New coil, cap, rotor, ignition module
-Tested pick up coil... Checks out ok.... hmmm...
-Checked timing slack by watching rotor when turning crank by hand... no sign of significant slack.
-Drilled out fuel mixture screw covers... adjusted and adjusted... and adjusted.
-Checked vacuum advance mechanism for operation... yeah, it does.
-egr... oh yeah, the egr is there, but all ALL other emission stuff removed by previous owner.... pfft, fool.
-A/C system removed as well
-Cheap reman 63amp alternator put in place. tested yesterday at local dumbnut parts store... they say its fine.
-New PCV valve... yeah, I went there.
Now, my thing is, when I stomp the gas. it acts like it starts to rev up, the rev disappears and reappears several times, but not consistenty. the harder I push the gas the more pronounced it is. but it doesn't change a bit. It just does not like more than half throttle at all. and I'm lucky to get half throttle most of the time.
Please get me outa the pig farm. it stinks in here!
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Sorry bud, you got lost in shuffle, glad some other boys stepped in...yes, they can be that cheap, parts quality is terrible these days...and I'm glad to see just a hair of positive pressure on both sides of rocker covers...that's what we want...too much usually indicates something like blow by...vacuum usually indicates something like intake leak... Try another wire could try to hunt down a set of Packard wires for the truck...they are OE, and seem to work nicely, or go high quality.... Porcelain... You could also run shields...basically... Just make the leaks go away lol... Also they have little "help" kits with wire separators... A decent investment in my book. When you get the leaks gone...dial that ol girl in on the road dyno with the screwdriver in your pocket :D
I'll check out the Packard set and Porcelain and "shields". Or lather the things up with Dielectric grease and call it a day haha! Thanks for catching back up with me, Knowing what the pressure at the valve covers means is nice, and good to know we're in the green on that too. I think my Saturn has blow by... That vacuum gauge is very helpful.
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