When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
ok, i installed the filter, set the timing.... problem still exists. advance timing, retard timing, same problem.... set it again, let the choke plate loose, problem got worse, tied the plate back to WOT, and now it's back to where i started. Tried the vacuum test, checks out fine. going to limp it home for a ten mile crawl.
does my carb have a power valve and could that be it?
anyone think i could have a burnt exhaust valve?
i'm trying everything i can, and taking every one of your sugestions. should I dump some seafoam in and pray?
now it idles a bit rough, in gear it wants to die. half throttle it still idles, WOT kills it, dead. won't go anywhere. i'm bout to take it to a mechanic, throw a few hundred bucks in front of his face, and leave.
everything is set to manufacturer spec. Fires up quicker than it ever has, just won't go.
I HAVE had a power valve go bad, but on an older carb it's more likely an accelerator pump diaphragm. Is it leaking at all on the front of the carb where the plunger goes in? A carb rebuild isn't really hard, and a heck of a lot cheaper than a new one (about $15 vs. $200). That APD is a VERY thin membrane, almost like a latex glove. All it takes is a pinhole to mess one up. Fixing the choke should be first priority, though.
i don't think it's the accelerator pump.... in park and neutral, it revs up to about 5k rpm fine..... it's the drive that kills it. having the choke wide open shouldn't kill it either. no leaks on the carb, gaskets are good. there is an exhaust leak due to warped headers. was about to put exhaust manifolds on it till this came up.
Generally if it has ever backfired through the carb is what will blow the power valve. Very thin diaphram. Not recomended for birth control. HAAA Try droping yer exaust at the Header collector and see if it runs better, This will tell if the cats or other exaust restrition is the problem. I'm still thinking vacuum leak or timing. Pull the cap off the Dizzy and rock the engine back and forth by hand to see how much the crank moves before the Rotor in the Dizzy does. Then bring the timing mark to TDC on the power stroke for # 1 and see if the rotor is pointing at the # 1 plug on the cap. This will tell us if the timing chain has to much play and or if it has jumped time.
Tried the carb kit... turned out the needle was completely rounded off, almost flat. swap the needle and runs great!! then got back in there and replaced everything else.
Thanx for all the help!! It made these repairs quite the adventure, and taught me an awful lot about my truck! Good work everyone!