1996

mooseye · May 5, 2009

I am trying to help a friend with his new to him truck.

It is a 96 silverado with the 5.7 auto.

The truck looks and runs great until you drive it a few miles. It seems to be starving for gas after that and will die completely sometimes.

My friend has replaced the fuel pump and filter. We have checked all things listed in the book for the fuel and emmision system as well as the ignition and most all sensors.

Any ideas? Has anyone had a simular problem?

Thanks,

Randy

VR021302 · May 5, 2009

clogged cats?

mooseye · May 6, 2009

clogged cats?

Nope, he gutted them also, first thing some one suggested.

grampadirt · May 6, 2009

You didn't mention codes.Are there any? You'd think with it dieing like that there'd be one..Maybe the ignition module is getting hot and shutting down...it's happened to me

Mike G · May 6, 2009

I would also suggest a look at the fuel pressure regulator.

--Mike

Draenor · May 6, 2009

I would also suggest a look at the fuel pressure regulator.
--Mike

+1 and inspecting the injectors.

mooseye · May 6, 2009

You didn't mention codes.Are there any? You'd think with it dieing like that there'd be one..Maybe the ignition module is getting hot and shutting down...it's happened to me

The only time the check engine light came on was when he had an O2 sensor out. He took it to auto parts and the guy told him their readers don't work on 96, hmm??. He has a guy coming that has a code scanner that will and hopfully that will show up something. I am thinking it won't since the message center is not showing anything.

Draenor · May 6, 2009

You didn't mention codes.Are there any? You'd think with it dieing like that there'd be one..Maybe the ignition module is getting hot and shutting down...it's happened to me

The only time the check engine light came on was when he had an O2 sensor out. He took it to auto parts and the guy told him their readers don't work on 96, hmm??.

They're Lying.

You didn't mention codes.Are there any? You'd think with it dieing like that there'd be one..Maybe the ignition module is getting hot and shutting down...it's happened to me

He has a guy coming that has a code scanner that will and hopfully that will show up something. I am thinking it won't since the message center is not showing anything.

It should not, unless the CEL is busted.

mooseye · May 6, 2009

He did take the ignition module in and it checked good. Of course that dosen't mean it is when hot. It doesn't really have to be warmed up. It will not rev above 3000 rpm when driving. It will go up to about 4500 in park or nuteral. I suggested the fuel pressure regulator today, but I think that would be more of a starting problem. I could be wrong. I thought I was once till I found out I was mistaken.

It has the central SFI but Ii don't see how they could run ok and then not if they were clogged.

I have been leaning toward the ignition mod from the start, but you can't check it hot and running, and it is expensive to throw electrical parts at it to test.

Lets make stuff so complicated in order to prevent pollution so that no one can fix it so now it will pollute more. Go figure??

cowboybinkz71 · May 6, 2009

Just a shot in the dark, but did ya'll check for a crimped fuel line somewhere. I'd also go through and check the wiring harness for a loose connection somewhere. Also, the MAF sensor may be going out (can't remember if my old '96 had one or not.) Oh and maybe a bad cam sensor too getting too hot.

pennzoil29 · May 6, 2009

Has he cleaned the throttle body, EGR valve, pcv, and the IAC. I know what you mean about throwing parts at it to try and figure crap out. Good luck with the scanner. I hope it tells you something.

mooseye · May 7, 2009

Fuel pressure checked good. It does have a MAF which needs a scanner to check.

He has cleaned the IAC and I think the EGR valve may need checked with a scanner also. New plugs and cap, full tank of 93 and a couple of bottles of injector cleaner. Not really any change since he drove it home. The cam sensor is nearly impossible to check while running.

mooseye · May 7, 2009

Here's one thing I may not have mentioned; When it begins to die or does die, you can restart it with no problem and then go again for about the same amount till it does it again. Now that does make me think fuel restriction at speed.

mooseye · May 7, 2009

I just talked to him. He has checked the fuel line and said it looks good but there is a slight kink in the return line. Might that cause a problem if it created back pressure on something?