Holley Carburator Issues

Cougar Community Classic Cougar Maintenance Restoration and Repair
1

I put the engine back in the GT-E last week and fired it up over the weekend. It fired right up and ran real good. I had a few water leaks where the tower clamps were not sealing on the bypass hose at the waterpump.
I drove back home and put some new style clamps on to stop the bleeding. I went for another test drive once the leaks were fixed, about 5 miles in the car started to run poorly especially at steady speeds or idle.

I drained the gas tank and put in 5 gallons of VP 110 octane since the car had been sitting for a while. I also used carburetor cleaner. It ran better but not perfect and then got bad again upon the next start up.

Turns out it is steadily leaking gas into the intake. I adjusted the front float down and got the car to idle and then started adjusting the float upward but before I saw gas it seemed to start running poorly again. I backed it back down a little and locked it (rain is on the way and it was late, had to get it put away). It ran better on the way to the shop but now it seems to starve for gas on acceleration and its still not perfect on steady speeds but is much better than it was and no more gas running into the intake.

I’m going to work on it more tomorrow and wanted some input since I know little about setting a carb properly. This carb has been on the car the 10 years I’ve had it. It may just need rebuilt.

To make things worse when I went to put my correct and restored GT-E carb on it one of the bowl inlets was stripped and that carb is inoperable until I can find another rear bowl to replace it. So I guess that when it rains it pours as the saying goes.

2

Dirt in the needle valve (most likely the back one). Scourge of the Holleys.

3

Thanks, I’m going to the speed shop today to see if they have some gaskets on hand. When I looked into the carburetor this morning the back barrels still seemed wet where the front were dry.

4

The rubber o ring on the outside of the needle assembly gets eaten by the methanol in modern gas. The leak can be slow enough that you can drive the car and it just seems rich, all the way up to gas comes out of the vent on top of the carb.

5

The O ring was not present when I went to put it back together. It ran just Ok when I took it to the shop to put it up. It just seems to be bleeding gas from everywhere. The next morning I took the carb back off and when I dumped the gas out the front bowl was empty. The back had plenty of gas in it. There is a diaphragm in the front metering block that must be leaking.

I took the back bowl of the C9AF U that I’ve been running and put it on the back of the restored C8AF AD that has the bad threads in the fuel inlet. They were exactly the same. The car runs absolutely fantastic now. I had no idea the power this car has in it. I found a station with non ethanol 93 octane and mixed 10 gallons of that to the VP 110 octane that I had put in it earlier, that along with some exhaust restrictions that I took care of has really made a difference in the performance of this Cat!

I’ll be putting some miles on her this weekend!

6

It never ceases to amaze me that these cars can run with missing carb parts.