howzatt

Does anyone have any advice to pinpoint or diagnose a problem I have been having with my '65? It cranks up fine and runs great when cold. Once it is hot and after I have shut the car off it has a hard time restarting. That and once it re-starts it has on occasion stalled (with no warning, driving on a busy street of course), it stalls ONLY after I have driven it somewhere, shut it off and re-started. Thanks for your help.

richbopp

Without lots more information I might suggest that it sounds like it could be a carb problem. It runs OK cold and then when the chock shuts off (down to normal idle RPMs) there's not enough fuel to the engine to keep it running. Needle valves dirty, chock float stuck, or something all together different.

Did it just start happening?

ctjackster

I'd be guessing carb - related too, but you might want to advise what engine you have and what carb currently sits on top of it (telling us the year is good, just need much more than that). Is the ignition ystem stock?

howzatt

It is a 65 with original 327/350 HP, has the original Holley carb, it is a pretty stock car, I do believe the ignition system is stock. It runs ok cold and seems to run ok until I shut it off, I can drive it around town for awhile and it is fine until I shut it off. Once I shut it off it has the trouble restarting and then stalling. It comes out of the higher RPM choke on startup fine and idles at about 700 rpm just fine. It is driving it for 20-30 minutes and shutting it down where it seems to have the trouble. Thanks for your replies!

richbopp

Now I think I have it.

Had a similar problem on my original 65 and my Dad (auto mechanic) told me the carb was perculating - as in the gas begins to almost boil. He rebuilt the carb and the problem went away. Turned out the float was sticky and kept dumping fuel when the engine was hot and not running. Couldn''t get it to start without holding the gas pedal all the way to the floor and even then had to crank and crank.

It's the same concept as flooding the engine with fuel by pumping the accelrator too many times. But that's my uneducated guess.

ctjackster

I am shocked, SHOCKED to learn it was a Holley causing you problems . . .

might want to search the archives on Holley percolation, Holley vapor lock, Holley hot start, etc. Suprisingly, yours is not the first instance of this issue

signed,

a fellow Holley 2818 owner

richbopp

I've got a rebuilt Carter AFB on the shelf in the shop if you want to replace the whole Holley horror show with something else.

howzatt

OK, it seems that we are narrowing things down a good bit. I have noticed too that when I go to restart the car (when hot) I have to press the gas pedal once or twice. On occasion I have to depress it and hold it to the floor when cranking to get it started. Hey my 65 is milano maroon as well, looks a lot like your photo ctjackster. Thanks again for the help!!!

ghostrider20

My 327/365 with the same Holley carb, as per the owners operating handbook says 1-2 priming pumps for a cold start, and for a hot start, you should just turn the key. If it is flooding, you can hold the pedal to the floor when cranking, but this will only identify the problem, and get you going.

Check to make sure the choke is releasing after the initial running of the car. IE on your second start after operating temp is reached. The chock defaults to a closed position, albeit only partial way when hot. The choke should quickly come come off, or "OFF" when started hot.

Now, is the engine having a hard time starting after a brief rest, or does this happen if you turn the engine off, then immediately try and re-start it.

Mark

howzatt

It seems to have the hard starting problem after it has been turned off and sat for a 20-30 minutes (for instance the last time was after I stopped to eat lunch). That may be a bit of anecdotal evidence though as I tend to stop and have it sit for 15-30 mins before restarting. I have not shut it off and then tried to restart immediately after it got hot, except after it stalled in the middle of the road with 45 mph traffic breathing down my neck.

JohnZ

When this occurs, does it crank real slow, or crank OK but doesn't fire?

howzatt

It cranks fine, it just won't fire off, plenty of juice for it to crank.

ctjackster

just had to eliminate starter heat soak as a possible cause, part of the process of elimination . . . . by the way, does your car run hot, or are you seeing this in the summer and winter, no matter what, running at a 180 - 200 temp?

JohnZ

Next time you drive it and park it for 20-30 minutes, before you try and start it, pull the air cleaner lid and move the throttle linkage to see if you get a pump shot of fuel from the accelerator pump squirters; if not, it's fuel percolation. Also, when you pull the lid, before pulling on the linkage, look down on the throttle plates for signs of raw fuel - if you see any, that's another sign of percolation.

howzatt

It usually runs in the 180-190 range on temps, particularly if I am moving. If I park it and it sits and idles it can get around 200 or slightly higher. I have only had the car since the beginning of summer and it is still hot where I live (I think it is upper 80s today), so no clue as to the response under winter temps. Any fix for the percolation or vapor lock? I have read that insulating the fuel line may help. Is the Holley carb that bad? I had a '72 and '73 that I believe had Rochester carbs and never gave me much trouble.

ctjackster

run the tests JohnZ describes (you have the assistance of one of the hobby's most respected guys right there helping you) and if this does seem to be a fuel perc problem, some have had success with a thicker gasket between carb and manifold (I take it you are running the original '44461 aluminum manifold) but others have even tried crafting a heat shield between the crab and manifold. The blend of gas you are seeing in your area in this season might also contribute to the prob

MikeM

" Is the Holley carb that bad? I had a '72 and '73 that I believe had Rochester carbs and never gave me much trouble.[/QUOTE]


Any Holley that has been run with no fuel filter and filled the needle/seat with dirt, has had the fuel bowl screws cranked down too tight and warped the main body and metering plate and had the base plate nuts overtorqued to the point that it is warped will definitley cause problems. They will even exhibit symptoms similar to yours.

The biggest thing wrong with those old Holleys is the people who work/worked on them. They are made out of soft, weak metals and require a certain amount of finess to avoid damage to them. Some people lack the touch. Others claim engine heat warps the same parts. I've seen no evidence of that being true.

If your carb is leaking externally/internally, flooding or otherwise not running right, I suggest you take it/send it to someone who knows how to check and straighten the main body and metering plates and true up the base.

I ran Holleys for tens of thousands of miles in years past and the ONLY problem I had with any of them was the metering plate and bowl gaskets would dry out after they set dry for many months.

I read a number of forums. Holley bashing seems expecially strong on the Corvette boards for some reason.

howzatt

OK I just drove the car around for about 20 minutes, have it parked in the garage and am waiting about a half hour to go try John Z's recommendation (thanks by the way). I have also noticed (mainly because I have been paying closer attention) additional symptoms as to the stalling. The car will run great as long as it is being given some gas. It has trouble idling. It will basically "drop" a few hundred rpms for a second or two and then bump back up to 750 or so. The rpms sort of occilate back and forth until the engine stalls, getting less and less rpms per occilation (always bumping back up to 750 but then occilating down to a lower amount). I have noticed the interior lights dim and bright with the occilation.

howzatt

OK I just did the check John Z recommended and both tests were neg for percolation (appears fine). Of course it is about 60-65 degrees outside and was about 85 when the problem occurred.

ctjackster

Mike - I have had NO problems with my Holleys either, but the chorus of Holley haters will surely raise up their voices . . . .