i have a 1976 C10 hd with a sb350, th350, 2wd, sigle cab long bed. bought truck with mostly original parts. did a complete tune up and now it has trouble starting and wont idle for more than 2-5 mins. after it dies it wont start with out cranking it for nearly a min. the carb was replaced with a 1405 edelbrock. adjusted properly and engine timing adjusted to the factory specs. will run some times for two days flawlessly then wont start at all. ??? driving me crazy. please help. if more info need just ask.

 

Could be plug wires. Are these carbon fiber? When it runs either crappy or good, jiggling the plug wires does it affect the rpm? Also could be something in the tank the pump is picking up on ocasion, or water in the fuel tank. Does this have hei or distributor? I am NOT leaning toward ignition other than plug wires based on your statement of runs for two days, this is intermittent.

 

im not sure if the plug wires are carbon fiber. there just some duralast wires and i havent tried jiggling them. i will check out the tank for contaminates. it is an hei system as far as i know the distributor looks the same as the one that was in my 84' c10. also i have an inline fuel filter before the fuel pump. is this ok and should it stay full or is it normal to bleed back to the tank?
thank you for your info so far. will be back after some more testing.

 

Inline is fine, and it is normal for the bowl to not be full.If it's hei I doubt carbon fiber plug wires, however they are still suspect. It has to be something fuel related in my mind, or something external ignition related. That means plug wires or connection, not the distributor, modules ect.

 

Have you checked your Fuel Pressure ?

 

mine did this after my carb swap. turned out it was the fuel pump and dirty plugs.

 

Sounds like a problem with the ignition module...... They can act up like that especially when original and the silicone is gone and they suck up the heat they get cranky