1999 5.2L
Plugs and wires less than 1 year
Battery less than 2 years
TPS - Less than 1 yr

Truck had a rough idle as long as I've driven it (Oct 2011). But it never threw a code until last summer. When I had it checked out, came back misfire on a cylinder, so I changed the plugs and wires. It ran great for about a month, then same thing happened. Rough idle, but no issues once you step on the gas. I talked to an uncle who was in town and he said TPS. Same thing, ran great for a couple weeks and then back to the rough idle. Now the truck will not start. It started hard the day before and the next day, I wore the battery down trying to crank it. It seemed like it would want to fire and stumble, but never start. Now it just turns over, but nothing!

I'm not a good diagnostition, but am a fairly competent parts swapper. I just dont want to spend a fortune buying all the parts I've seen people swap out just to have the same problem crop up.

Any advise will be greatly appreciated.

 

Do you know if you have spark? and fuel pressure? If you do, i would start with a compression test. If you don't have spark or fuel pressure, then that would be the place to start at.

 

Gonna sound like dumb questions, but what are the best ways to do that in the driveway? Take a plug out and hold it? Never had to do that before. I have fuel in the injector rails cause I just took them off, but I don't know if the injectors were working.

Any advice for the shade tree novice?

 

if you try cranking it and pull a plug and its wet, and smells like fuel, you are getting fuel thru the injectors, also check the fuel pressure at the rail as you could have fuel but not enough, as for checking spark, yes thats the best way, just dont hold it too close to the open plug port as you dont want any of the fumes to ignite

 

Just like sharp said. If you have any questions, everyone is here to help.

 

Replaced injectors and IAC. Now idles like a hot rod. Is that just until the ECM learns the new parts? I left the battery disconnected during the swap. Is it something that will resolve itself?