Little bit of grey smoke during idle....

[Mrturner1]

So I've been working out of town and I got back yesterday and wanted to take a drive in the old C10 see'ins how I finally got it dialed in. I'm letting it warm up and my wife comes out and says it's burning her eyes in the house, and I can see the air is a little hazy around the back of the truck. I drove it today and pulled over to check it out, and at an idle I can barely see the smoke coming from the tail pipes, but what was weird is it was sunny outside and I could see the shadow of it on the ground right after the tailpipes by the rear tire. Weird. Not sure what that means, but I'm really hoping my bottom end its going out especially because I finally got the truck dialed (mostly) so I can drive it now and not worry about reliability.

Motor is 10.3-1 355cid, RHS 170 heads, Comp 280H, 1.5 roller tips, Edelbrock performer rpm manifold, 1" phenolic spacer under a Holley 750dp that has 71's in front and 77's out back, 6.5 power valve and stock pump cam and pump cam position. I'm certainly no expert on jetting, and my hunch tells me that 71/77 is too much, it came with 75/76 jets. Timing is 32* total, with 18 initial and all in at 3000 rpms. TH400 with 3000rpm stall, 3.73 mini spool rear

[Grumpy old man]

It's the hot fuel you've been dumping in the tank , run it out and use premium unleaded .

[Mrturner1]

Originally Posted by Grumpy old man

It's the hot fuel you've been dumping in the tank , run it out and use premium unleaded .

Can you explain just so I understand what you mean? That stuff can make grey smoke? It started right after I fattened up the a/f mixture screws on the carb too. I turned those in a half turn and that off idle stumble went away, I may have over done it though I suppose. I hope you're right, I was so bummed havin just got the thing running good finally

[Grumpy old man]

hot fuel is famous for burning eyes

[Mrturner1]

Originally Posted by Grumpy old man

hot fuel is famous for burning eyes

Well ya I get that part, but could it be causing the smoke I'm getting while its idling?

[Grumpy old man]

Stop looking for things to fix and just drive the dang thing . move on to brakes and suspension and lock the hood down .its running good LEAVE IT ALONE !

[davepl]

Running lean can make it burn the eyes. But so can rich. Without a exhaust gas analyzer you're unlikely to diagnose why your wife doesn't like it.

I think the correct answer is "Because it's old and doesn't have catalytic converters so I'm going to go drive the damn thing so it's not sitting at home making bad smells and causing me to want to take it apart again!"

[Mrturner1]

It definetly smokes it's not just her saying that lol it's never smoked before, and smoke usually means something bad is going on, especially if it just started for the first time since I got it. Do you guys drive yours around if they start to smoke or do you typically figure out what it is? I'm not so much worried about the burning eyes, it's got a gallon of 110 and probably way too big a jet in the primary, I can deal with that. But it goes from never even a puff of smoke to making the front yard hazy and a visible smoke at idle is a little concerning.

[Mrturner1]

Ok so I went to take a video and I'll post that up shortly, but I noticed something while J was down there, the smoke is DEFINETLY black.

[Grumpy old man]

Originally Posted by Mrturner1

Ok so I went to take a video and I'll post that up shortly, but I noticed something while J was down there, the smoke is DEFINETLY black.

If it's black it's running rich a mixture fouling issue , too much fuel .