Smoking Like A Diesel

[383mrollg]

Hey Sweptline forum it's been a minute.

I revived the truck after sitting 10 years, then life happens and it sat for another year...or two

pulled the carb again, cleaned everything out, siphoned old gas out of the tank that was left in it (still some in the lines), new gas with stabilizer, new plugs, fixed some broken wiring yada yada...start her up and she is smoking like crazy out the exhaust! When I first got it running two years ago this was not occurring, I was able to drive it around.

Pulled all 8 plugs and did dry compression test with engine cold. 155-160 on all 8. Weird thing was happening though on cylinder 6 fuel was spraying out of the carb hole. Ok so I am flooding the engine, but why only cylinder 6?

did some research and stuck needle can be culprit or floats are set way high. pull sight plugs and rock truck back and forth and it trickles out so float level is good. Pull the needles out and the gaskets are deteriorated on both primary and secondary. Replace those, problem persists as I pulled cylinder 6 plug and fuel still sprays out. Brand new plugs are dark black after running for 10 minutes except for cylinder 6 which is wet from fuel.

Oil is clean and full put in full synthetic when I did it last, coolant green and full.

Any help on where to look next for the issue? I am about to throw money at a new carb but figured I'd check here first.

70 d100, 383 727 I've attached pics, link below to video

https://photos.app.goo.gl/W8EfKSnh32kXQ3t29

Thanks

Chris

[Wildergarten]

did some research and stuck needle can be culprit or floats are set way high.

Metering blocks on Holley carburetors can be very sensitive to contaminants and are VERY difficult to get clean. If you think your problem is carburetion and you can get another, I'd go there.

Next time you let it sit like that, drain the carb and blow it out.

[nutz]

would think 6 is lowest , closest to the leak might be stuck float valve
would be careful it doesn't hydro lock

[383mrollg]

I replaced both needles, primary and secondary. The bowl vents are not pushing gas through them. When the truck was running I pulled both sight plugs out and gas is not pouring out of there either. The engine is not starting now but is turning over. I pulled #6 plug again and turned it over and fuel still spraying out of the plug hole. not sure if the cylinder is just full of fuel or what is going on. Someone on another forum mentioned to replace the engine oil too in case fuel got mixed in? Does that make sense would the fuel be able to seep past the rings?

I just pulled all of the plugs and a few were wet, few were black carbon and a few clean.

I also hooked up fuel pressure gage and checked in while turning over (not running) and saw fluctuation between 5-10psi...hard to actually tell without the engine running what true fuel pressure is.

I'm scratching my head here on how its flooding without the normal indicators of flooding. when I look down the carb after turning it over for 5 seconds I can see everything is clearly wet with fuel.

Going to do a leak down test next to see if anything going on with rings/valves.. compression test showed 155-160 on all 8.

Thanks,

Chris

[nutz]

oh yes change the oil
think at this point once the carb is full of fuel
just unbolt the carb and carefully lift straight up and see if fuel is leaking out the bottom ....

[PwrWgnDrvr]

Yes, fuel in the cylinder will leak past the rings.
Every holley on a vehicle Ive acquired has leaked fuel like that. After engine shutoff they would drain into the manifold. Not a fan of holleys.

[383mrollg]

Replaced the carb with a summit 750. The truck is eating it up loves it. Problems all gone