1996 Silverado idling and running issues

[Bentzenracing]

Have a 1996 Silverado with a 305 Vortec and a 5 speed tranny. The problem I am having is it is really hard to start and when it does it blows black smoke that looks like a cummins starting up. When driving it it cuts out like someone is shutting the key off and turning it back on and will not idle. Have changed the ear valve and the throttle position switch. I am all out of ideas and so is my mechanic. Any ideas or someone that had similar issues?

[Dirtautoguy]

when was the last time you did a tune up?? I know its a simple thing but it gets overlooked sometimes. my truck had some similar issues and all it needed was a good ignition tune up. cap, rotor,air filter, plugs and wires. it sounds like it is getting plenty of fuel but not enough air or not enough spark. or the fuel pump and injectors arent supplying the fuel consistent enough for it to start. but I kind of doupt that. I would check your ignition and air first.

 

have you checked your O2 sensors? they could be telling your computer to add fuel like crazy.

 

does it blow smoke continuously after you get it started like its constantly getting to much gas? or just shortly after?

 

a little more info on what you have tried would help us help you but we will do the best we can.