Quote:
Originally Posted by Bandit130
I would think more about fuel pump, fuel filter in carb. Just spitballing here could be something else. Just a thought.
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I did start considering the fuel pump thinking of it more.... Going to pull the line and see if it's got a good stream when cranking (I don't have a gauge to put on it).
Quote:
Originally Posted by Matt Man
Is the vacuum advance working? should be about 34-36 degrees around 3,000 rpm.
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Yep. When I rev the engine the timing mark moves right up to the 30deg/+ area.
Quote:
Originally Posted by Dead Parrot
Possible vacuum leak around intake gasket or carb base gasket. Do the spray with carb cleaner test.
Does it still have the exhaust riser valve? Those can stick shut and force half the exhaust through the intake crossover which kills higher rpm performance and can overheat the carb.
Does it still has the original Y pipe? Some of those had double walls and the inner wall would collapse, mostly blocking the exhaust, Also killing performance.
Check the rubber lines from the tank(s) to the frame. If those are original, they are probably crumbling away and letting air into the fuel system. Same for rubber lines from dual tank valve to frame if equipped. Even if hoses recently replaced, mice sometimes like to sample taste the hoses, also letting air in.
Nice looking service truck.
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Thanks Parrot. Good idea, I'll check the intake for vacuum leaks. The passenger side around the intake manifold does look a bit iffy, so I wouldn't be surprised if it's sucking air. If it means anything, this can be hard to start too when hot. Sometimes cranking for a bit and when it catches, it won't idle well... or catch then die again... have to keep the throttle cracked... I suppose that could signify a vacuum leak?
Riser valve is still there, though I think the PO cut the butterfly out because you can almost make a full turn with the bell-crank.
Y-pipe is gone. Currently has dual straight pipes with glass packs, no crossover pipe.
Gas tank lines have all been re-done too (and filter).
Quote:
Originally Posted by geezer#99
Thinking more on it, might not be cam.
Could be fuel pressure problem.
Too much pressure in your case.
Who rebuilt the carb?
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It's only happened twice, but when starting this, the float has stuck. Couple taps to the side of the carb and it stopped. Not sure if the float hung, or if the pump was pushing fuel past.
I rebuilt it. Very familiar with carburetors, but this was my first time rebuilding a Q-jet, so wouldn't be surprised if something didn't turn out right...
Going to check for vacuum leaks and fuel pump functionality today...