Engine dies

[CW4B]

70 C20. She’s very rough, never run well/smooth since I’ve had her but today engine kept stumbling, spitting & sputtering then dying. Particularly when more loaded like going uphill and more so when it shifted into 2nd. Like it was running out of gas. After stopping and putting in park, she would start right up but run rough and sputter again and die after a bit of driving.

She’s been sitting for awhile, maybe a year without much operation, but I did originally drain tank and put fresh gas (1.5 yrs) and recently filled it up (only 4 gal) and she has a remanufactured but original carb that I “tuned” IAW instructions using a vacuum gauge. I also had installed a new fuel pump and replaced all rubber hoses in fuel line. Haven’t checked fuel filter but it came inside remanufactured carb. Also have installed EFI in lieu of points, new distro cap, wires and plugs.

Not sure how the begin troubleshooting. Seems like many overlapping sytems it could be. Fuel? Carb tune? Spark? Timing? Distro (vacuum) Timing chain?

Help? I plan to rebuild the engine & rewire everything, but hoping I could drive it in town for awhile for now.

[Stocker]

Originally Posted by CW4B

I did originally drain tank and put fresh gas (1.5 yrs).... Haven’t checked fuel filter but it came inside remanufactured carb.

Could be any number of things (I am no mechanic) but I'd look at fuel first. Am I reading that you put in fresh gas 1 1/2 years ago? If so, it could be bad and may have even fouled the carb. Check that filter in the carb also.... I had a pleated filter fail and I will only use a bronze one now.

[dmjlambert]

I agree with Stocker and I'm not a mechanic either, but I'm learning and successfully done a lot of stuff on my truck with help from you guys here on the forum, so here is my advice. I suggest check the things you mention you haven't already, like timing and fuel filter. But first check and recheck and then check again that you have the firing order correct on your new spark plug wires, since you changed out that distributor cap and wires.

The fuel filter is something easy to check and inexpensive to change. I suggest replace the fuel inlet gasket every other time you change the fuel filter. The fuel inlet gaskets are also inexpensive but not all car parts stores carry them in my area, so I order mine on eBay. Be careful to not cross thread or over tighten the fuel inlet fitting when re-installing the fuel filter, and do not over tighten the fuel line connection to the inlet fitting.
Here is a thread with my adventures in that area:
http://67-72chevytrucks.com/vboard/s....php?p=8242862

Here's the thread with my adventures in setting the timing and using a timing light.
http://67-72chevytrucks.com/vboard/s...d.php?t=753416
I suggest explore timing a little.

[maverickmk]

My money is on a stuck choke.

[LockDoc]

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My money is on a plugged or missing sock filter on the end of the pickup tube, inside the tank. Once it falls apart the pump will suck the pieces into the pickup tube and plug it up tight. After it quits or you shut it off the pieces will float away and it will start again.

LockDoc

[truckster]

Originally Posted by LockDoc

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My money is on a plugged or missing sock filter on the end of the pickup tube, inside the tank. Once it falls apart the pump will suck the pieces into the pickup tube and plug it up tight. After it quits or you shut it off the pieces will float away and it will start again.

LockDoc

That's also the first thing that comes to mind for me.