White smoke / pools of gas in intake

[nellis003]

Hi all,

I just bought my first C4 - I've had C3s before but found a 1984 Crossfire Corvette project and thought I'd try to get it running.

The car sat for six years before I bought it, and when I got it started there was a lot of white smoke coming out the tailpipe. I figured it was a bad head gasket, because the smoke looked like coolant smoke. But when I did a compression test, I got around 140 in each cylinder. Most of the sparkplugs were wet, black, and smelled like gas.

So I removed the crossfire setup, and found pools of gas sitting in the intake. Raw gas is getting in there somehow.

My questions are:

Is there a way to diagnose where the leak is? I'm not sure if I should try replacing the seals on the throttle bodies or the injectors themselves.

Could this be causing the white smoke, or is that a separate issue?

Thanks for any input.

Nick

 

[catbert]

White smoke on start-up - valve guides?

 

[KANE]

Hi all,

I just bought my first C4 - I've had C3s before but found a 1984 Crossfire Corvette project and thought I'd try to get it running.

The car sat for six years before I bought it, and when I got it started there was a lot of white smoke coming out the tailpipe. I figured it was a bad head gasket, because the smoke looked like coolant smoke. But when I did a compression test, I got around 140 in each cylinder. Most of the sparkplugs were wet, black, and smelled like gas.

White smoke- perhaps those are valve guides.

If you have pools of gasoline and your plugs smell like it too... sounds like you have a bad- or two bad- injectors. Have you tried watching it run and checked the spray pattern? If it drips or doesn't look like a nice, fanned out mist- you could have a leaky injector.

I'd expect some thin amount of gas to line the walls- that's what is called AE or pump shot. Pools are different... they are the result of either way too much fuel being delivered (bad programming for fuel maps) or the injectors malfunctioning/wrong size.

 

[nellis003]

Update

Hi all,

Well, I kind of went all out in chasing down this issue. The compression test was good on all cylinders, but since I had a gasket set and some time, I tore the engine down and put in new head gaskets. I also replaced both injectors, and when changing one out noticed that the nozzle end had been smashed pretty good. And one of the injector wires was hanging together by one single strand.

Long story short, I put in all new gaskets, new injectors, buttoned up some wiring issues, and got it all back together... only to have it smoke just as bad as before.

I'm convinced this is a fuel issue. I drained all the old fuel out before engine disassembly and put in fresh gas, so I don't think old gas is the problem, but it does look like the injectors are DUMPING gas into the throttle bodies. Both have a nice-looking cone sized spray, but a ton of gas comes through while cranking. So much that I can disconnect the injectors from the harness and the car will start right up and run for a few seconds with no gas coming in. With the injectors connected, she's VERY hard to start.

So, what would cause the injectors to throw that much fuel? In comparing my engine to photos and diagrams from the net, I can see that the EGR solenoid is gone. Just completely missing, and the hoses have been plugged up. Would this cause problems like I'm having?

Also, does anyone want to buy a 1984 Corvette? Fun father/son project, REAL cheap.

Thanks,
Nick

 

[nellis003]

Anyone have any suggestions?

 

[Antz81]

I'm no expert on the crossfires, but your EGR being removed and plugged up shouldn't give you any troubles.
Have you checked your fuel pressure?

 

[KANE]

Anyone have any suggestions?

Do you have a video of it that you could share where we could see how thick it is and we could hear how it is running?