[66GMC]

Hmmm ... I'm not as familiar with the Carter AFB (Edelbrock) carbs as I am with Holleys, but Holleys DO have a gasket or o-ring where the choke control housing bolts to the carb.

Many carbs (i.e. Holley, Motorcraft, Rochester) used a black phenolic choke cap with a bi-metal spring inside. Some of them were electrically heated, but some of them used a hot-air "choke stove" that was mounted in the intake manifold exhaust cross-over. A tube ran from this choke stove to a fitting on the back side of the choke housing, and hot air was drawn into the choke housing using a small amount of vacuum.




When I checked Edelbrock's on-line parts catalog, I am seeing a lot of "choke block-off plates" ... which I surmise to mean that Eddy carbs do not have this provision? You only have the choice of converting to manual or electric? Perhaps someone with some experience with AFB / Eddy carbs will chime in?

Lastly ... you have already had a couple of suggestions to install a new carb kit (and float?). You've said that the carb hadn't been used much for something like 8 years ... and I suspect that the accelerator pump, gaskets, and any other componenst made of rubber, cork, paper, nitrophyl or even brass (i.e. floats) may have deteriorated.

Good luck ... sounds like you're on the right track with the diagnostics ...

[chevyrestore]

thanks yeah, im just going to have it rebuilt by a professional so I have a warranty on it and see if that does the trick. Atleast I found some sort of a problem with it to justify spending the money on it

[chevyrestore]

alright everyone. I had the carb rebuilt, put it on, same problem. How would I check for flat spots on the cam? At this point what should I do? Im at a loss.

[chevyrestore]

I went at the intake again with another can of brake cleaner and I found a couple spots where the idle fluctuated when I sprayed it but it barely fluctuated (you had to really really be listening). Do you think that would cause it or would it have to be a bigger leak? I did notice also that there was an oily breathing around the intake as well, not sure if that helps for diagnostics at all or not but just something to note.

[454C10]

pull off the valve covers and start the engine. Look for rockers not moving as much as the others. The rocker that aren't moving as much are the flat lobes. Also the push rods should be spinning.

[chevyrestore]

I think I finally figured this crap out. After seeing that spray affect the motor slightly I taped off the edge of the intake and edge of the valve cover and sprayed the edges of the intake with the gasket sealant spray (copper stuff) to temporarily goop up any leaks, torqued the hell out of the intake bolts, and test drove it. 99.99% better.

With that being said I will get some new intake gaskets and give that a try. I put on the stock fel-pro ones about 2 years ago so this surprised me, any suggestions on a better gasket that might seal and last a little while longer? Im skeptical about using the pepboys junk performance intake gaskets or going back to felpro stocks again.

[66GMC]

IMO, Felpro make a good quality gasket.

I've re-read (skimmed) through the thread looking to see if the intake is the stock cast one, or an aftermarket aluminum one ... and didn't find the answer.

I used the Felpro intake gasket designed for a stock 454 with cast intake and cast heads on mine, and had issues with the "china wall" gaskets getting pushed out.

A couple of recommendations from the membership here were to use the Felpro Performance gasket with an aluminum intake, and to disard the china wall gaskets and use Permatex "Ultra Black" silicone instead.

No, I haven't swapped out that intake gasket as of yet.

[chevyrestore]

awesome thanks for the info, ill go with the felpro performance set then. I work for Toyota and have the FIPG silicone which kicks ***...best silicone ive ever seen in my life, ill use that for the front and back instead of the rubbers they give. Would you guys also recommend the spray on copper gasket spray to seal it a little better also or just run the gaskets dry?

[chevyrestore]

alright geez talk about one thing after another. I was about to do the intake gaskets but I started it first to move it into a shady place to work on. I noticed a misfire. Found now that the number 8 cylinder plug wire cracked and was misfiring-replaced ALL plug wires, Found bad vacuum advance (I think it misfired and backfired once and destroyed the advance, I had a few extras-replaced the advance, working good now.


slight popping out of passenger side pipe.


pulled all plugs- I replaced them about 100 miles ago, still look new and good, put them back, out of no where the popping was gone but now at the driver side. Now I get to pull the driver plugs and check those...so weird. After new wires, synching down the original intake gaskets, rebuilding the carb its almost completely gone but still have a little misfire under acceleration and small popping out of the driver pipe under a power brake.


Ill keep you updated but this one is weird and stressful haha

[chevyrestore]

ok guys I got it going nicely! turns out it was mainly the ignition causing the problem. Im sure fixing the leaking car and intake manifold did help though also. I do have one question though...

after rebuilding the carb I ran it for a couple minutes, ran OK but not great because of the bad coil but when I shut the motor off I saw fuel dripping from the nozzles (indicating a stuck float am I right?) that happened 3 or 4 times in a row and all of a sudden its fine again, is that just a fluke or should I take it back to the rebuilder so he can say "it all looks fine to me I dont know what your talking about"?

[chevyrestore]

Originally Posted by chevyrestore

ok guys I got it going nicely! turns out it was mainly the ignition causing the problem. Im sure fixing the leaking car and intake manifold did help though also. I do have one question though...

after rebuilding the carb I ran it for a couple minutes, ran OK but not great because of the bad coil but when I shut the motor off I saw fuel dripping from the nozzles (indicating a stuck float am I right?) that happened 3 or 4 times in a row and all of a sudden its fine again, is that just a fluke or should I take it back to the rebuilder so he can say "it all looks fine to me I dont know what your talking about"?

Sorry ignition coil to be more specific on the cause of the problem, forgot to type that