Holley Carb Issues

[dannystarr]

Thanx...That bad-boy looks pretty thick. Probably seal up well. Problem is, I already have a 1/4" Phenolic spacer to help prevent fuel in bowls from boiling. I am almost flush with thread height. I think I need one between the 2 that is not too solid. I don't want to install longer studs if I can help it. I better do some more research. Keep the ideas coming. D

[DuWayne Ladner]

Yep, gaskets now a days or simply not good quality gaskets, as my builder showed me metering block gaskets that were way out of place on most of the passages. Again I ‘m gonna jump this high horse, of most of the old faithful venders in our hobby is not getting good quality stuff from the far east! Believe me, as I know from a repair business that I was in for 30 years, last 10 to 15 years, raw products going far east and pure junk returning in the form of replacements parts. Dealt with a lot of brass and stainless steel, soldering the 2 together. I’ll stop.

[bertfam]

You really won't need the phenolic spacer if you go with the thick Holley 108-12 gasket.

Ed

[jdv69z]

What do the plugs look like? Too much fuel at idle will cause all kind of headaches. Plugs will be carbon black, will foul prematurely. I was thinking bad power valves, but you replaced them. Power valve is basically a switch turning on and off additional fuel under power. If the power valve diaphragm is ruptured, that additional fuel will be added all the time which would cause excessive fuel at idle. The diaphragms can be damaged by backfiring. High Vacuum at idle holds the power valve/switch closed. Just some ideas.

[dannystarr]

Ed,
 I didn't realize that thank you. I may pull that phenolic spacer and try the Holley one. If I can get some heat insulation AND better sealing, I am in!

 I pulled a couple plugs, and they were dry as a bone and light brownish. No sign of any fouling. My friend said set the carb on the intake with NO gasket and see if it rocks. I will check the base for flatness. I drilled/installed the backfire valve/ball to help things out if it does backfire. But no backfire issues even while trying to keep it running. It sure seemed like it wanted to backfire bad, but never did. That's why I feel it is a fuel idle circuit issue. And not an ignition issue. I am burned out on it for now. I'll get to it in the coming days. Meanwhile car #1 is still running good with car #2 carb. So I am going to just leave it be.

QUESTION... Should I run the 2 slot or 4 slot power valves?... Does it make a difference?... Also, do we know who make the best quality Valve? D

[1971ls6]

4 window are supported to be quicker, for the price difference, it’s worth it.

Remove your needle and seats, take a good look and clean it with brake cleaner

[lynnbilodeau]

Sounds like it is loading up with fuel.   Here is the clue:  "When you try to start it, it takes ALOT of turning over without giving it any gas and then finally it starts."
Classic sign of a carb letting in too much fuel.

Because you already changed the PVs, probably needle and seat.   May not even need replaced.  May just have a bit of junk in it not allowing it to shut off fuel.

[NAPA68]

Danny,

I'm a bit late to the party for this conversation. Am I safe to assume your carb is full rich at idle? If so, try this. With the carb off of the engine, place it on a carb stand (or some equal length 5/16 bolts that are secured to the base plate to suspend the carb). Fill the float bowls. Does the carb leak down while the carb is sitting there? That would only get exaggerated by engine vacuum at idle.

As you get it off of the idle circut......it runs fine. Of course, engine RPM can cover up some some fuel and ignition problems. If I were a betting man, I'd say the issue may exist with one of the metering blocks / gaskets / and or main body fit. It sounds like fuel is getting in where it does not belong when it's supposed to be working strictly on the idle circut.

That all having been said, I too would suggest reaching out to Eric @ Vintage Musclecar Parts. Eric does ground zero rebuilds above and beyond full restorations. So often, I found out how warped the main bodies are, to say nothing for the metering blocks. Eric recently helped me through an problem child 4150 that was on an LT-1 Corvette. It was an issue as I described above.

I can appreciate yoiu not wanting the bother anyone, nor laying the car up for a period of time. In my own humble suggestion, put a pro on it. You'll save time and aggrevation that you would not otherwise be able to put a price on.

Tim

[sixt9x33rs]

Danny I suppose you have no gas coming out of the vents or flooding anywhere?
I would check the needle and seat and confirm no trash has found it’s way on the seat.

[dannystarr]

Finally got some time. Pulled the carb. Pulled it apart part way. Cleaned it all up and sprayed it down with carb cleaner and blew it out. ALL the holes on both metering plates BOTH sides. Installed new blue gaskets. Set new gaskets with light greasing on intake. Starting hooking things up. Went to put the throttle rod C-Clip on with a screwdriver push and it went flying into the cowl vent. Found a small thin baby magnet and fished it out. Good Times!! Fired it up and had a couple bowl leaks. Tightened them up and a few seconds later... cha cha . cha... cha   chug   chug     chug      chug       chug   and dies. EXACTLY what the hell it did before. It ran approximately 35 to 40 seconds. Gave it a little gas and tried to start it, and it turned over like wildfire, all-the-time trying to start but didn't/wouldn't. I will pull it again and check the needle and seat, as I forgot to do that. After that I am sending it out? NOTE: The throttle rod dripped on the left side, but only while the car wasn't running. Never leaked a drop there before when it used to run great... D

[dannystarr]

I think I figured it out. I was cleaning the needle and seat and noticed 2 or 3 baby threads. I put a new one in and set it. Wouldn't start. I went back to check it and it was sticking up 1/4" past where I set it. I can move the needle and seat up and down in the bowl by hand. Female threads are stripped out! I need a bowl. I contacted Summit, Jeg's, classic car parts places no go. Even Holley won't have any until 8/04/23. They should have 100 available, ridiculous!! 

  Anybody have a front primary bowl for a List 4053 / 4150 Series 780cfm Vacuum Secondary? HELP!!! ... Danny

[dannystarr]

I think I found one... D

[dannystarr]

NOPE, still need one.. 134-103  D

[uscrichter]

Try Phillip at Custom Carburetors