AFTER OVER A YEAR OF WORK, I HAVE MY VETTE READY TO DRIVE AGAIN. PROBLEM IS, THE ENGINE DOES NOT WANT TO RUN CORRECTLY FOR ME (NO MATTER HOW SWEETLY I TRY TO TALK TO HER). I HAVE A 1965 327/350 WITH A 4BBL HOLLEY 2818 (RBEUILT "NEW" FROM CHICAGO CORVETTE). WHEN I FIRST PUT THE ENGINE ALL TOGETHER (NO ENGINE REBUILD-JUST DEGREASED AND PAINTED-INSTALLED CORRECT INTAKE MANIFOLD AND CARB ONLY) AND STARTED IT, IT HAD A VERY DIFFICULT TIME STARTING. THE PROBLEM TURNED OUT TO BE THE CHOKE LINKAGE HAD STUCK IN THE CLOSED POSTION. ONCE CORRETCED AND THE CARB JETS/FLOATS ADJUSTED THE ENGINE RAN LIKE A CHAMP. I WAS SO HAPPY I PUT THE INGNITION SHIELDING ON. TO DO THIS, I (PERHAPS MISTAKENLY) HAD TO ADD LENGTH TO THE WIRE COIL LEAD THAT COMES FROM THE ENGINE WIRE HARNESS AND HOOKS ON TO THE NEG POST OF THE COIL SO THAT THE IGNITION SHEILDING WOULD FIT OVER THE DIST CAP AND COIL. IN THE MEANTIME I ACCIDENTLY BROKE THE LEAD TO THE BALLAST RESISTOR (IT'S AN ORINGINAL) AND I REPLACED THE BALLAST RESITOR LEAD WITH A NEW CRIMP ON STYLE CONNECTOR. AFTER MAKING ALL THESE ADJUSTMENTS, I GO TO START THE CAR A WEEK LATER AND IT RUNS AS IF A COUPLE OF THE SPARK PLUGS WIRES WERE ON WRONG. I HAVE CHECKED AND RECHECKED UNTIL I AM BLUE IN THE FACE-THE WIRES ARE ON RIGHT. A MECHANIC I KNOW SUGGESTED THAT THE PROBLEM MAY BE WITH THE CARBORATOR-HE SAYS THAT HOLLEY'S WERE NOTORIOUS FOR THE VACUM DIAPHRAMS ON THE INSIDE FAILING, THUS MAKING THE CARB RUN VERY ROUGH. I PULLED THE PLUGS LAST NIGHT AND NOTED THAT THEY HAD SOME VISIBLE GAS ON THEM AND THEY WERE ALSO BLACK WITH CARBON (NOT OIL). I CLEANED THEM UP, CONFIRMED THE GAP AND PUT THE PLUGS BACK IN AND IT SEEMED THAT THE CAR RAN BETTER. I PULLED THE #1 PLUG OFF TO SEE IF IT HAD SOME GAS ON IT, THUS INDICATING A CARB DIAPHAM PROBLEM AND THERE WAS NO EVIDENCE OF GAS-BUT THE CARBON WAS BACK AGAIN. I CHECKED AND THE DWELL ANGLE WAS 30 AND IT SEEMED AS IF ALL THE CYLINDERS WERE HITTING. OH BTW A FEW DAYS AGO THE CAR STARTED UP FINE AND RAN GREAT AGAIN. THE NEXT WEEK (LAST NIGHT ACUTALLY) IT RUNS LIKE ITS DYING. LOTS OF BACK FIRING-LIMITED POWER ETC. BEFORE I TEAR THE CARB APART TO REPLACE THE VACUM DIAPHRAM SHOULD I LOOK FOR AN ELECTRICAL PROBLEM? IS THERE A POSSIBILITY THAT I AM NOT GETTING ENOUGH VOLTAGE TO THE POINTS? HOW DO I TEST THIS STUFF? PLEASE HELP AS I AM RAPIDLY LOSING WHAT LITTLE HAIR I HAVE LEFT (NOT TO MENTION THE FACT THAT I AM GETTING TRANSFERRED TO A NEW DUTY STATION IN JUNE). THANKS MUCH, KEITH
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith, A couple of simple things I may suggest are the negative lead is going to the distributor, another is change the condenser in the distributor. This may sound thivial but the condenser was Scott Sinclair's problem at the national two years ago. It's the little things that cause the most problems. If your vette has not been backfiring the power valve should be ok. There is the possibility that it is stuck from fuel varnish. My suggestion is use only a rectangular opening HOLLEY power valve (6.5 vacuum value, thank you Bill Clupper). Be sure to use the correct power valve gasket for this type power valve or it WILL LEAK. Let us know how you make out. -
Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith, A couple of simple things I may suggest are the negative lead is going to the distributor, another is change the condenser in the distributor. This may sound thivial but the condenser was Scott Sinclair's problem at the national two years ago. It's the little things that cause the most problems. If your vette has not been backfiring the power valve should be ok. There is the possibility that it is stuck from fuel varnish. My suggestion is use only a rectangular opening HOLLEY power valve (6.5 vacuum value, thank you Bill Clupper). Be sure to use the correct power valve gasket for this type power valve or it WILL LEAK. Let us know how you make out.Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith,
This might sound dumb. The problem you have is probably the plugs. New plugs or not they can foul out permently due to excessive gas. This has happened to me a few times. The carb is probably fine . Having choke stuck for awhile would cause plugs to get quite wet and might create a gas fouled plug. Cleaning a gas fouled plug won't fix the plug . With engine running you can pull one wire off at a time, from distributor cap, to determine which plug(s) are not firing. Use a good pair of insulated pliers. If engine stumbles when wire is removed it is a good guess that that plug is firing. No change would cause further investigation. Good luck.Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith,
This might sound dumb. The problem you have is probably the plugs. New plugs or not they can foul out permently due to excessive gas. This has happened to me a few times. The carb is probably fine . Having choke stuck for awhile would cause plugs to get quite wet and might create a gas fouled plug. Cleaning a gas fouled plug won't fix the plug . With engine running you can pull one wire off at a time, from distributor cap, to determine which plug(s) are not firing. Use a good pair of insulated pliers. If engine stumbles when wire is removed it is a good guess that that plug is firing. No change would cause further investigation. Good luck.Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith: You mention back firing in your post. If you are back firing through the carburator this very likely have blown the power valves. If you are going to replace them, as others have suggested, you might also want to take an additional preventative step and install blowout protection. Theese are little check valves which install on the bottom of the carb and prevent power valve damage during backfire. I have not done this myself, but read about them and when jerry Luck redid my carb he installed them for me. As long as you are going to be in there anyway it sure seems worth the effort.Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith: You mention back firing in your post. If you are back firing through the carburator this very likely have blown the power valves. If you are going to replace them, as others have suggested, you might also want to take an additional preventative step and install blowout protection. Theese are little check valves which install on the bottom of the carb and prevent power valve damage during backfire. I have not done this myself, but read about them and when jerry Luck redid my carb he installed them for me. As long as you are going to be in there anyway it sure seems worth the effort.Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Many good suggestions are provided by others, but I'll add my two cents. Why not use science instead of guestimation? Put the car on an engine analyzer and SEE what's going on with your ignition system....Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Many good suggestions are provided by others, but I'll add my two cents. Why not use science instead of guestimation? Put the car on an engine analyzer and SEE what's going on with your ignition system....Comment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith-I have a 66 300 hp with a Holley that i thought was causing my rough running,fouling plugs and just general misery.The kicker was that it would come and go without warning.I rebuilt the carb,checked for vacuum leaks all to no avail.I pulled my distributor cap and went to check the points and found the breaker plate was loose on the bushing.I could move it around quite freely.Upon removing the distributor i also found the shaft and bushings to be worn and fairly sloppy.After rebuilding all my intermitent problems disappeared.You didn't mention the distributor condition so i thought i suggest checking it.I missed the first Bloomington Gold Route 66 road trip because of this!Actually i used my 25th annv. Trans Am with a picture of my 66 in the glovebox to go and boy did i get the ribbing!!!Hope you get it straigtened out,Best Regards LouComment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Keith-I have a 66 300 hp with a Holley that i thought was causing my rough running,fouling plugs and just general misery.The kicker was that it would come and go without warning.I rebuilt the carb,checked for vacuum leaks all to no avail.I pulled my distributor cap and went to check the points and found the breaker plate was loose on the bushing.I could move it around quite freely.Upon removing the distributor i also found the shaft and bushings to be worn and fairly sloppy.After rebuilding all my intermitent problems disappeared.You didn't mention the distributor condition so i thought i suggest checking it.I missed the first Bloomington Gold Route 66 road trip because of this!Actually i used my 25th annv. Trans Am with a picture of my 66 in the glovebox to go and boy did i get the ribbing!!!Hope you get it straigtened out,Best Regards LouComment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Gents, I just wanted to say thanks to all for the outstanding advice received through this forum. The problem was solved with a new power valve located in the metering plate. I put in a new set of plugs to elimiate the potential of damage as a result of gas/carbon fouling. I will install a new set of spark plug wires just to ensure I have all my bases covered. I will also check out the distributor to see if the breaker plate and/or the dist in general is in need of rebuild. The engine still seems to be running a little rich. After a popower vac diaphram replacement, should I re adjust the jet/floats/idle etc.? Any simple tips? Again, thanks to all. KASComment
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Re: HOLLEY CARB PROBLEM FOR 65 VETTE
Gents, I just wanted to say thanks to all for the outstanding advice received through this forum. The problem was solved with a new power valve located in the metering plate. I put in a new set of plugs to elimiate the potential of damage as a result of gas/carbon fouling. I will install a new set of spark plug wires just to ensure I have all my bases covered. I will also check out the distributor to see if the breaker plate and/or the dist in general is in need of rebuild. The engine still seems to be running a little rich. After a popower vac diaphram replacement, should I re adjust the jet/floats/idle etc.? Any simple tips? Again, thanks to all. KASComment
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