Thread: New engine...lots of smoke out the tailpipe

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Just put the first real miles in on a new engine, 350 mild port 230/230 .050 cam, edelbrock 1406.
It did fine the short trips testing and what not but today it started smoking real bad if you let off the gas after giving it more than half throttle, let it idle too long, or dont touch the throttle down hill. At all other times it does not smoke.
At first i thought its burning coolant but it wreaks of gas, i tried re tuning the carb back to completely stock and i tried running it just off the fuel bowl, both with no change.
I checked it over this morning and it Does not appear to be losing coolant but my oil level did rise, it is NOT murky like it has water in it.
I noticed my valve cover breather was also puffing a little smoke at idle, same white/blue color but it is not oily at all. It smells like gas.

Car following me says white smoke, looked like it had a blue haze in the mirror. It seems to have started missing at the same time, could this be a lot of excess fuel not getting burnt?

Its 90 and i drove over 50 miles with no temp issues

Any help is appreciated

Does this engine have a mech fuel pump? If so, is it new? I have seen them fail and pump fuel into the oil pan while still providing enough fuel to run the engine. I've seen it happen on 2 SBC's and a few air cooled VW's.

The rise in oil level with no loss of coolant is a clue. Has to be fuel, since that is the only other fluid in the engine.

If it's not the pump, then the carb is dumping way too much fuel in. Edelbrocks don't like more than 4-5 psi of fuel. It used to have that in the manual. The last "stock" AC pump I threw a gauge on put out 9 pounds and caused the Q-jet I was tuning to flood like crazy.

One more thing to check if you have power breaks check the fluid level I have had the m/c go bad and suck break fluid intp the intake it burns white also if it is auto trans pull the vacuum line at the modulator and see if it is wet with t-fluid

Originally Posted by Hotrod46

Does this engine have a mech fuel pump? If so, is it new? I have seen them fail and pump fuel into the oil pan while still providing enough fuel to run the engine. I've seen it happen on 2 SBC's and a few air cooled VW's.

The rise in oil level with no loss of coolant is a clue. Has to be fuel, since that is the only other fluid in the engine.

If it's not the pump, then the carb is dumping way too much fuel in. Edelbrocks don't like more than 4-5 psi of fuel. It used to have that in the manual. The last "stock" AC pump I threw a gauge on put out 9 pounds and caused the Q-jet I was tuning to flood like crazy.

I pulled a couple plugs and threw a timing light on it real quick.
#1 is still wet and wreaks. 3 looks relatively ok, maybe even lean.
#1 is cutting out after about 2k..no light at all. It was fine when i set the total timing.
I took the fuel line off after it started smoking to see if it was pressure and it smoked til it ran out the bowl but ill get a guage on it.
I think im losing spark and that cylinder is filling up with fuel, what do you guys think?

Originally Posted by ted dehaan

One more thing to check if you have power breaks check the fluid level I have had the m/c go bad and suck break fluid intp the intake it burns white also if it is auto trans pull the vacuum line at the modulator and see if it is wet with t-fluid

Interesting ill look into both. Thanks!

I'm not real fond of spark plug wires that have much more than 500 ohms resistance.

Originally Posted by ted dehaan

One more thing to check if you have power breaks check the fluid level I have had the m/c go bad and suck break fluid intp the intake it burns white also if it is auto trans pull the vacuum line at the modulator and see if it is wet with t-fluid

It was indeed leaking at the modulator, thats gotta be the clouds of white smoke. Thanks for the tip!

Originally Posted by NTFDAY

I'm not real fond of spark plug wires that have much more than 500 ohms resistance.

I was looking into getting some firecore50 wires

Originally Posted by 93F250

I was looking into getting some firecore50 wires

A little pricey for my taste. I prefer Taylor Spiral Core, but that is merely my opinion.

Lower fuel pressure at the carb inlet to 5 psi or less and replace all the spark plugs.
.

Well one fuel pump, a vaccuum modulator, pcv, oil change, and set of plugs later its running correctly. Still working on the tune, bogs when you mash on it (doesnt even really wanna run out my converter stall). Then its good when it picks up, plugs look great now

Accelerator pump.