i got an 87 that did the same thing and i replaced the fuel pump and come to find out that it was the fuel pump relay so check your relays.

 

Great Info.........I have a 1985 chevy s10 Pup 2.8l v5, 2wd ,2 bll carb...I'm having the same problems rough idling, backfire through the intake,spits and sputters and stumbles on accelleration at around 30-35 mphBut I've been noticing latel that if I pump the gas pedal enough time it will clear up and run good until I have to stop ..Then it sarts all over again..I was wondering if I have a sock filter sense I couldnt find an inlline filter anywheres..Does anyone know??..and do I have to drop the tank all the way out to change the filter ?

thanks alot

 

You should have both a sock and an inline. The sock filter is inside the tank on the end of the fuel pump. There should be an inline on the frame about middle of truck.

 

Thanks for response
Come to find out I did a carb. kit install and my accellerator pump was shot plus a few needle valves and both valves in the 5 cyl. so I'm down to just a rough idle and I think most of that is an intake leak around the carb I gonna have to redo the gasket and btw ..I have a sock filter and a filter inside the carb

thanks again
knyte.

 

Hey, sorry I haven't been on the site in a while, just saw your post. Actually I'd gone ahead and subscribed to alldatadiy.com. For the 5 year subscription it was only like 30 or 35 bucks as a I recall and has been pretty helpful for a lot of things.