~Stingray

Hey Guys,

My 1980 has been starting to put out whitish exhaust smoke, but I don't notice oil missing.

I pulled a spark plug and the tip is white. I was told by a friend this means it's running lean and can also cause the white exhaust.

Suggestions of where to begin to get this running correctly again? Tune the carb?

Thanks.

gerry72

Sounds more like coolant in the cylinder(s). Does the exhaust has a sweetish odor (assuming you have antifreeze in the radiator)? Or does it have a noxious, eye watering odor? The sweet odor would be coolant turning to steam during the combustion process. The noxious odor would be unburned fuel, which is what you'd expect from a mixture lean enough to "white" a plug.

How do the other plugs look? Any other associated issues like overheating, coolant loss, poor engine performance?

~Stingray

Its definately a noxious odor. I have a one car garage that I share with a motorcycle and a grill. So when I park the vet someone stand at the back to direct me so I can pull as close to teh wall as possible on the passenger side.

Eyes water and burn, and smells like exhaust, not sweet.

cv67

sounds like its running real lean

like the above posted said ck the other plugs and compare
Is it stock, what changes have you made?

does it surge at all at cruise rpm or "trailer hitch"/feel real down on power?

https://www.summitracing.com/parts/a...SABEgL7WPD_BwE

These will tell you what your engine is doing so if its rich or lean very easy to troubleshoot many different versions. Uses an 02 bung just make sure there are 0 exhaust leaks upstream.

~Stingray

I haven't checked the other plugs. Just the one. But I can do that if you think it is necessary. I figured if I was seeing the exhaust and it was hurting my eyes, checking them all wasn't necessary as I know I have an issue.

No mods, its the original engine. Rebuilt 40k miles ago according to owner I bought it from.

No surging, but sometimes it idles high when I push in the clutch. And wont' stop without driving it for a bit.

I haven't really noticed it lacking in power, but it is a 1980. I thought it was a little sluggish since I bought it for a v8. Government regulations had these down to 180HP or something stupid like that.

bj1k

I would check the oil for a gasoline smell. Chevy engines were famous for defective fuel pumps that would let gasoline get into the oil pan when the seal goes bad . It thins the oil and can destroy the engine in a short period of time. You would see a lot of smoke coming out of the exhaust . If you smell gasoline , flush it and add clean oil and filter before starting the engine .

~Stingray

I will check it. But last time I checked I don't recall that. And the last time I had the oil changed the mechanic didn't say anything either.

REELAV8R

If this is a recent development and you factor in your high idle issue, it could be a vacuum line has broken or come off either contributing or causing your lean condition.

~Stingray

I started noting it last year. I was hoping to get to it as a winter project. That didn't happen. So I am pretty bummed that I haven't been able to drive it yet this year for fear of what might be happening.

A vacuum issue would cause this? I didn't realize the vacuum was part of the air flow for combustion.

REELAV8R

Vacuum for you cars systems comes from below the carb, basically the intake manifold.
So the more air that is allowed into the intake manifold without going through the carb makes the overall mixture leaner due to the fact that it didn't pass through the carb and pull fuel as it entered the manifold.

~Stingray

So you are saying the issue is not the carb letting in too much fuel but a broken hose or one that is disconnected letting air in someone along he line. Leading to more air than needed?

terry82

I would look at the cat .they were bad when new .replace with new better flowing .or you could open up what you have .then check to see what it smells like.

~Stingray

I have magflow exhaust....no cats.

terry82

coming back to the carb.i would check my vacuume and timing.Then I would rebuild carb .

bashcraft

I had a 1 ton pickup long ago that after I put a set of headers on it, the exhaust and plugs started burning white. I was told that the better flowing exhaust caused the mixture to go a little lean.

REELAV8R

It's just something to check.
If it was fine before and now it's not and you haven't changed anything then something has changed of it's own accord. A vacuum leak is something that can develop over time. It could be a hose or the actuator on an item.
If you have made a change and this started occurring, then that change is likely the cause of the condition.

Too little fuel for a lean condition

MelWff

concerning the white smoke, have you been keeping an eye on your coolant level to see if it is gradually going down. If it is get a a coolant hydrocarbon test kit to verify you have a possible internal leak, head gasket.