My truck sat up most of winter. It starts and won't idle until it gets hot. It reeves way up then falls off and stops. As I try to drive it..in first gear it will lurch and reeve up then die off and bog down? Can't keep it running without paddling the pedal. Replaced the fuel filter. added new gas to tank, replaced plugs, looked for fuel leaks(none), and now I can hear the fuel pump running for about 30 sec and turning off. Cked for varmit nests, cked air filter ....nothing there. When I finally get it to idle roughly it cycles up high then down low then eventually dies. As I drive it it races up and then bogs down???help!! It has always idled fine and no problem until past winter.???

 

Might be fouled injectors. I'd run some Techron Complete down the gas tank, and take it out for an "Italian tune-up". Sounds like you might have a bad fuel pump as well.

 

Would the fuel pump just go bad sitting there? thx!!

 

Well, it's a 1989 Chevy so his fuel pump is old. It's never a good idea to allow a vehicle to just sit for long periods of time.

 

Exactly what happened to my '90 5.7. Filter located driver side behind rocker panel.

 

I replaced fuel filter on drivers side but it did not help? It idles up and down until it dies. If I give it gas it chokes and bogs and dies. If I run it as hard as I can it feels like a bucking horse!!

 

Ignition systems can break down under load and produce the symptoms you describe.
Might be a good move to look there.

 

Do you mean....plugs?????? ignition system???

 

Are you talking rotor caps? etc???

 

I'd start with plug wires, how old?