Chevy Nova Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
268 Posts
Discussion Starter #1
So fuel is shooting into my carb after I shut the engine off, and its causing it to flood and making it hard to start. I adjusted the floats to about an 1/8" off the sight plug so I don't think theres an issue there. So my latest theory is that the gas is boiling from the heat of the engine and spitting into the carb. So I guess Holley makes a heat sheild to combat this problem but I have a few questions that someone might know the answer to. DOes this sheild work ? Are these 4150 & 4160 carb notrious for this problem?? Are they closer to the Intake or something??
 

·
Registered
Joined
·
1,150 Posts
check you needle and seats, could be trash in there holding them up from seating all the way.....just pull the needle part out and look at it....
 

·
Premium Member
Joined
·
269 Posts
I use a 1" wood spacer. No boiling issues. Mine did flood before w/ the 1/2" plastic one. I would check your needle and seat too. I found some plastic chip in mine before!
 

·
Registered
Joined
·
268 Posts
Discussion Starter #5
Ok, I finally got around to addressing this problem and I still havent solved it, so my steps went like this .... #1. Bought a heat sheild, installed it, and the fuel still spit out. # 2. Swapped the sheild for a 1 in wood spacer...... fuel still spit out and flooded. # 3. Adjusted the floats to 1/8" below the sight holes, this did not work. #4 Took out the needle checked for blockage, none present, reinstalled it....didn't work. As far as the heat riser suggestion, I don't have heat risers as I run headers. So I don't know where to go next.....any suggestions?? FYI, Fuel pump is mechanical, running 7lbs pressure, inline filter looks clean, I have a rubber hose line running to the carb and the fuel is bubling out of the shooter nozzle. Fuel line runs by the water pump and the heater core return line, I don't think the fuel would be boiling becasue of this. HELP
 

·
Premium Member
Joined
·
630 Posts
Ok, I finally got around to addressing this problem and I still havent solved it, so my steps went like this .... #1. Bought a heat sheild, installed it, and the fuel still spit out. # 2. Swapped the sheild for a 1 in wood spacer...... fuel still spit out and flooded. # 3. Adjusted the floats to 1/8" below the sight holes, this did not work. #4 Took out the needle checked for blockage, none present, reinstalled it....didn't work. As far as the heat riser suggestion, I don't have heat risers as I run headers. So I don't know where to go next.....any suggestions?? FYI, Fuel pump is mechanical, running 7lbs pressure, inline filter looks clean, I have a rubber hose line running to the carb and the fuel is bubling out of the shooter nozzle. Fuel line runs by the water pump and the heater core return line, I don't think the fuel would be boiling becasue of this. HELP
The Heat risers in the heads where the intake manifold heat crossover would be. Are those blocked off? Or do your heads even have heat risers? would be the question. I was going to suggest a fuel pressure issue also.
 

·
Registered
Joined
·
1,272 Posts
Check the vent on your fuel tank. I had a carb do the exact same thing one time. It was brand new and built by a very reputable company. As a matter of fact we purchased two carbs at the same time from them. I tried everything to no avail. I sent the carb back to them a couple of times and they could not duplicate the problem on a dyno engine. I tried the other carb we bought from them on me engine and it worked just fine. They changed different items out on the carb each time, but could never get it right. They supposedly even changed the main body. They ended up refunding my money and I bought a carb from someone else and have had no trouble out of it. I actually think the car ran better with the fist carb other than the fuel problem after shutting it off. The other carb we ran our drag car for years with no problems it was an excellent carb. My first one was a 650 dp also that had the trouble.
 

·
Registered
Joined
·
268 Posts
Discussion Starter #10
Ok, I will try the regualtor next. I have camel hump heads, so I suppose I do have heat risers (wasn't familiar with them), if it requires me to take the intake off though I think that might be my last resort. Where would the gas tank vent be? I think it might be a pressure issue due to the fact the metering blocks were so cold when it was doing this I could put my hand on them. Literally, i can sit there and watch the needle on the pressure guage go down from 7 1/2lbs to zero as it spits fuel in the carb.
 
1 - 10 of 10 Posts
Top