OK, I'll try to keep this as short as I can...

Got the '69 out last week to drive it to work. Got on the interstate, car was running great. I was cruising along about 60 when all of a sudden it started sputtering badly. I checked my mirrors to see if I could get over to the emergency lane, and there was a huge cloud of smoke pouring out of the tailpipes. Never lost oil pressure, never made any unusual noises. Rollbacked her home.

Pulled the plugs, they were totally fouled. Compression check showed 180 - 195. Pulled the valve covers, everything appears to be fine. It would spin over, but wouldn't crank. Checked the ignition, and found that the wires running from the dist. to the Mallory box on the fenderwell had fallen onto the headers and melted a couple of them together. Thinking that it probably fried the electronics, we replaced it with a new Lectric Limited breakerless system and new coil. Finally got it to crank, but it is still running very rough, and pouring HUGE amounts of light grayish smoke out of both exhaust pipes.

Any ideas? No signs of water in the oil. BTW, it's a 350 with probably 20,000 miles on it. Edelbrock aluminum heads, roller rockers, gear drive, Holley 750, most all of the normal goodies. Help!!!

Thanks,
Jeff

 

something tells me youre not going to like the answer to your question...Im not totally sure so Ill leave it alone...good luck though kiddo, youll need it.

 

Where the plugs carbon or oil fouled? Also, did you change the plugs when you put the new dist in?

If it's oil it could the valve guides.

Dave

 

You did replace or at least clean all the plugs right?

Did you do a compression test on all cylinders?

This is definitely kind of a weird one, but I have a hunch that your ignition might have still been ok. I just can't fathom how your ignition dieing would suddenly make you belch out oil smoke. It might be time to pull the heads and have a look at the cylinders.

 

Check the carb. Betcha a float is stuck.

Brett

 

Dave, the plugs were oil fouled... but I can't imagine valve quides going out that quickly. This happened just really quick. One minute it was running great, the next minute it's puking all this smoke out the back.

81 Vette, give it up man! I'm a big boy, I can take it. What are you thinking?

 

wcsinx, yes we did a compression check - all cylinders were in the 180 - 195 range. You may be right, the ignition may have been ok...

Brett, I was wondering about the carb. If it was suddenly dumping too much gas, could that cause these symptoms?

 

Compression was 180+ on all eight?
I bet you have a dead cylinder .....

Equal smoke at both pipes probably rules out the bottom end, so make sure!!

All 8 plugs fouled?.....carb or even an intake vacuum leak.

BTW, I'm guessing like mad as I know Crap about engines!!
...but willing to learn out of the responses

 

Holleys are notorious for doing that. Sudden loss of adjustment or trash in fuel is most likely the culprit. Too high a fuel level will dump gas into the engine making it run rough and stall. Know how to check the float level?

Brett

 

Summerfun, yes all plugs fouled badly. Lots of smoke out of both pipes. Good news I took car of all the mosquitos in the neighborhood for a while!

Brett, you pull the sight plugs on the side of the bowl, right? I think my buddy who was helping me checked that, but I'll go back and look again.

 

Because you said things happened suddenly..........I suspect an ignition problem right away. If the thing ran fine before on the same carb......there is no reason to suspect a carb problem........let us know what you find........but I think it will be a quick fix with a new coil and possible distributer rebuild.

 

I am the last person you'd want to diagnosis your engine problem but.....Could the loss of ignition wires cause pre-ignition and throw your timing off? Also check the cams position for possible slipage. Just guessing, and these would be easy to check too.

 

Thanks for the suggestions guys. You've given me some good ideas of things to check. I'll keep you posted on what I find!

Jeff

 

If the float gets stuck on a Holley, gas is gonna be coming out of the breather tube when it does run. This happened to a friend of mine and he said the car would only run if he was running it pretty hard down the interstate. We pulled the front bowl and found it had specks of rust in it. We cleaned the bowl out real good and he has not had any problems again.

If the car is making black smoke, it is fuel.
If the car is making white smoke, it is coolant.
If if the car is making blue smoke, it is oil.

 

could be intake gasket leak(oil in side) there will be so time to burn the old oil out of the system even if it fixed

 

First of all I would look at what happened. Car was running fine and then all of a sudden it started smoking and died. With that said, you can basically rule out many things such as worn valve guides causing this issue. I am not stating that the valve guides are good or bad, but they did not cause this problem. I would be leaning more towards a carb problem. I would think that if it were the carb dumping too much fuel the smoke would be black in color. Looking at plugs that have 20,000 miles on them would not be the best thing to determine the problem. The good news is that the carb is a Holley. They are not that difficult or expensive to rebuild but like anything else, you want to be reasonably sure you are fixing a problem or it's time and money not well spent. The other important fact is that both banks are showing the same symptom of smoking. To me that means that it's not being caused by something that would only affect only one side. One thing that confuses me is when you say the engine spun but did not crank. They are essentially one in the same, although crank is generally associated with the spinning of the engine by use of the starter. I assumed you meant the engine spun/cranked but did not start/run.
Let us know when you find out .

 

If you have not done this yet, you need to first replace the plugs. Put new ones in there and go over the basics. The ignition got messed up from the burned/grounded wiring. The plugs got trashed during the ignition misfiring. You replaced the ingnition but has it been installed corectly? You need fuel, air, and spark at the right time.

The carb will need to be doing something obvious for it to be the culprit here. Raw fuel spouting out would be an example but otherwise it should run.

-Mark.

 

Is it running now? Still smoking? What color? Joe

 

I know very little about this, but if the wires burned on the manifold, is it not likely the cylnders fired and didn't fire several times as the wires could have been bouncing around and stuttering sorta before they went. This would cause raw fuel from one and not the other etc. Just thougts. I would start by trying to replace cheap stuff and go from there.

 

OK, where is that little red-faced icon when you need it? After many many hours spent tinkering with this thing, it turns out that the problem was..... are you ready for this.... are you sure you're ready for this.... well OK, but I warn you, the truth is really ugly.... it seems that SOMEBODY who shall remain nameless (but he looks an awful lot like me) pumped $12.00 worth of DIESEL fuel into his Corvette!!!! See, I told you it was ugly! We discovered it last night when we were putting my buddy's carburetor on to rule out that as the problem. Spilled some fuel on the floor of the garage, and my buddy realized when he was under the car checking the fuel pump that "hey, this doesn't smell like gas". I stopped by the gas station this morning to check it out, and sure enough, they have ONE pump out of about 30 that has diesel, and yes, that was the pump I bought my fuel at that day, and yes, the diesel nozzle is right next to the 93 octane.

So now that I've gotten my bonehead move for the century in, life should be good from here on! Thanks for all of the suggestions guys. Now I'll go find a big hole to crawl into until the jokes stop!

Jeff