I am having to pump the gas pedal 20+ times when it's cold to get it to start and that is with the choke on. It was like this with the original carburetor and with a rebuilt carb as well. Any ideas on how to fix this?
if you have points check them, worn rubbing blocks (common with the chinese and mec=xican sourced crap we get these days) will close your gap and change the dwell and timing. Find, read. and follow a good ignition trouble shooting chart. And remember the old axiom, 90% of all carburator problems are electrical, and 90% of all electrical problems a re fuel system related.
Seem to recall these engines having an issue with worn distributors. Many of them had only a single bushing down in the middle of the housing instead of a pair at the top and bottom. Probably saved GM a nickel a unit to build them this way but they didn't wear well. Pull the distributor and check for excessive side play in the shaft. If it's bad enough the points will barely open at cranking and idle speeds. If they do start, with a little more RPM, they mostly sorta kinda run OK. And since it might actually be a carb problem, when you hit the throttle are you getting a good accelerator pump shot?
Replaced point, condenser, cap, rotor, wires, checked the dwell and timing. The distributor has some wear but not bad and it still takes 3-4 trys with pumping the gas pedal 20+ times to get it to fire. It also likes to run with the choke cable pulled out a 1/2 inch or so.
Well that would indicate a lean mixture condition but more in the idle or main circuits. Closing the choke a bit fattens up the mixture a little. Cupping your hand loosely over the airhorn with the engine running will simulate the same condition. When you set the manual choke, is the choke valve closed completely? If so, it may be trying to start and then floding itself out. The choke needs to have maybe a 1/4" clearance between the upper edge of the choke valve and the airhorn, especially right after the engine starts at fast idle. That said, it's still hard to beat a working, properly adjusted, automatic choke. More stuff you can check: Sufficient accelerator pump shot. Good cranking compression. Look for vacuum leaks. Check cranking vacuum and idle and running vacuum. Check for good electrical grounds. What other work has been done recently, possibly just prior to the hard starting issues?
Changed the oil and took her on a 50 mile highway trip and she runs and starts great. The truck had been sitting for three plus years, so my guess is it just needed to be run.
Quote "changed the oil", I bet it had to do with the lifters not pumping up, or taking too long. thick oil would do that,,, New oil somehow got the lifters working again..
it did have some lifter noise before the oil change and it also has the wrong dipstick as it reads full at 2 quarts.
With five quarts of oil in the engine and after letting it run a few minutes and letting it sit a few minutes check the oil and mark the stick at where the oil level is and you should be good to go. that's nice when an oil change and a little road trip seems to cure the ailments of the rig.
Should it do this again after sitting for a week or so, look in the carb and see if your getting gas when pumping the throttle, if not it doesn't mean the acc pump is bad but here may not be any gas in the carb, I notice that on the toys sitting here the ones with manual fuel pumps after sitting for a week or two won't pickup gas, if I fill the float chamber thru the bowl vent they'll start right up and at a higher rpm the fuel pumps pick up the gas, they also have new fuel pumps,and will start normal every couple days, the other toys with electric fuel pumps start normal even after sitting for a month, I blame todays gas, we've also had problems with the pony motors on old cat diesels not starting, and the gas tank is above thew carb on those, take them apart and clean them and they run, it seems that there is something that screws them up like a schallic or coating that needs to be wiped off or fresh gas in them to disolve whatever is one them.
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