1986 C10 dies when accelerator pressed

[Tioga651]

I have an 1986 C10 with a newly rebuilt carb. For a long time I was experiencing intermittant power loss, followed by an increase in engine temp and a change in the engine and exhaust sound. The transmission would not shift right during these episodes. Now, after a few minutes of warmup, the engines dies under load. So I can't even drive it out of the driveway. I suspect one or more of the thermal vacuum switches that control the egr, distributor vaccum advance and all the other functions now controlled by a computer.

The engine itself is in good shape and idles perfectly. Is there some way to diagnose which of the several TVS's that may be responsible? I thought about bypassing them by jumpering around them with a piece of hose or blocking existing hose as necessary. The problem is they seem to interact with each other dynamically changing the configuration depending on emgine temp. I have been having trouble figuring out just what ports should be open, closed or vented at a particular time.

Thanks for your help. I would like to restore the truck, but a good running engine is required.

[skipr]

Did you rebuild the carb yourself? Almost sounds like your accelerator pump is flat.Meaning when you give it throttle, the pump isn't forceing fuel down the venturi but a mass of air is.

[my85c10]

Hey skipper, if the mass of air is his problem, how do you solve that?

[taco85]

easy solution: get a holley or edelbrock carb brand new. easy fix.
tried rebuilding a quadrabog, screw it. not worth it

[bigj-dog]

If you want to check for vaccum issues, you should be able to block off every vaccum port except the ones that go to the power brake booster, the distributor vaccum advance, and the transmission modulator (if you have an automatic). All of the others you should be able to live without, at least temporarily. If your dist. is not a vaccum advance model, then you'll have to trace back and keep hooked up whatever runs that. If it were me and you have an electronic dist. and a carb that has wires off the air horn in the front, I'd ditch them and find a vaccum advance dist. and an older quadrajet and use them instead. Those mid 80's setups never seemed to work very well.