Subfixer

New problem for me. 327 dressed as 365 with LT-1 cam, 461 intake and brandy new rebuilt 2818 Holley carb.

Starts right up first thing in the morning. Choke works exactly as it should. Fully opens when car is warmed up. Runs great all day, no overheating issues, no carb stumbing throughout the rpm range, timing is right on. Nice "lumpy" idle at 750-800. Runs smooth as silk.

Problem is when the car sits for more than 5 minutes, but less than 20 minutes. It just won't start.

First I thought it may be flooding due to misadjusted floats and gas heating up.... Floats are correctly adjusted (hot engine) and there are no obvious hot gas leaks into the carb. No hot gas smell. No gas leaking out of the throttle shafts. I can crank it almost till the battery gives up with my foot to the floor, but no start.

Then I thought, OK, maybe it's the opposite and I have no gas. Checked the accell pump nozzles while opening the throttle and I get a great shot of gas. (even with multiple pumps). So that's not it.

Tried the ignition system next. I had problems in the past with a bad coil when hot, so I tried another new one. Same problem.

If I wait about 20 minutes, the car starts right up and drives perfectly again. I have run out of ideas....

JohnZ

You're getting air and fuel, so lack of spark is the culprit; heat-soak is the other variable - first thing I'd suspect is the coil.

ctjackster

I would have guessed coil too (that was the solution to a only when hot problem I was having) but I think you have addressed the coil already, plus the car is not dying on you at temp, just a restarting problem.

gonna have to show you the room where we keep all the bad things about holleys hidden, right this way to the intake mani heat fuel perculation area, I fear . . .


this is a sample thread:

http://forums.corvetteforum.com/show...um_id=4&arch=1

Dave62

A suggestion to try is to bypass the ignition resistor and try to start.
The resistor is still hot and drops the voltage to the points. Your switch may be the problem. It should take the resistor out of the loop when starting. I have seen this fail.
Dave62

Subfixer

John, Tried a new coil, still no good.

Jack, I thought about fuel perculation, but there's plenty of gas when I pump the throttle. Since the accell pump get's it's gas from the bowl, I'm assuming there's some in there. These cars didn't do this when new, did they?

There is no exhaust heat riser valve in the exhaust. I'm using the F/I spacer. Passages in the intake are blocked also.

Dave, Getting full 12V to the coil from the starter when the ignition switch is in the start position. Then back through the ballast resistor in run.

Keep 'em coming....

JL66REDCPE

Paul -- are you using points or one of those breakerless systems like mallory unilite or pertronix ??? I had a problem in my BB with a Mallory unilite at heat soak. The wires were becoming so limp from the heat that they could no longer carry juice. As a fix, before I converted the car back to transistor ignition, I shielded the wires and the problem went away.

Subfixer

Still using the tried and true points and condenser.

K2

Have you tried holding the throttle wide open (no pumping of throttle) while cranking? This clears any flooding and would indicate if it is a fuel flooding problem.

ctjackster

Subf, you are not alone : http://www.ncrs.org/forum/tech.cgi/f...80682&expand/1

Hitch

How about did you replace the starter during your rebuild?? The "new" starters have a different spring and it's more prone to causing hard starting due to heat soak.. I'll have to dig into my archieves but I've had a discussion with my mentor and I know there is a difference.... He and I discussed it previously on email.. I think.. Boy the Bud Light is good this afternoon.. I have an early case of CRS..... Maybe this will jog someone else's memory though... Dave...

64roadster

Subfixer, I would have suspected starter but since you did not say the engine was turning over slowly, I have to presume it is cranking freely.

Subfixer

Starter spins quickly.....

I think I found it. I had to take the car back to the alignment place because one of the rear camber adjusters moved. While I was watching the guy try to start the car, I saw the "dreaded" black smoke when he finally got it running. So it IS a fuel perculation problem. It eventually started by keeping the throttle full open. I had attempted this before, but it wouldn't fire up for me. Guess I didn't try long enough.

I'm trying to figure out why this is happening, since I'm sure this was NOT normal in 1964, and besides the different gas mixtures we have to deal with today, I came up with a theory....

I'm running a drop base air cleaner, 66-67 style, instead of the "correct" air cleaner. Since the correct air cleaner base does not drop as far down as the one I have on there now, maybe the drop base is helping funnel and hold the heat right at the carb. That should be rectified once the correct air cleaner finally comes off backorder.

Also noticed today that my fan clutch is shot, so I'm not getting a good airflow across the engine, at temperature, while idling. New one on order.

Anyway, problem found, now I just have to figure out how to resolve it without changing the appearance of a stock engine.

Oh, stupid question here.... I've had Carter & Rochester carbs for years now, and I seem to remember that setting the idle mixture is reversed on a Holley. Is that right? Out for lean and in for rich, or is it opposite, just like the others?

Thanks.

RMBLROAR

What I recall about the starter spring is that it acts like a dying battery. The car may crank very slowly, crank like it has too much advance or not crank at all. Since none of those conditions were mentioned and it sounds like the starter is turning freely, the spring probably isn't the problem.
It really sounds like a coil to me but that's been addressed as well. How about the wiring to the coil? He didn't say if there was ignition shielding involved. I've had to replace the battery wire from the coil to the starter on my '66 due to it being fried sometime in its life before me. This happens when the top shield comes in contact with the battery coil terminal when trying to put it back on. I know the '66 top cover has an insulator but it can happen anyway if one isn't careful. It'd be easy enough to check by putting a wire directly from the solenoid to the coil, bypassing the one in the harness.... Frank

Subfixer

Frank, thanks for the input. My shielding has an insulator inside it, but I did take a look at the wiring anyway. Everything is good there. Have the same prob with the shielding on or off.

Pretty sure it's fuel perculation. Just got to fix that.....

Hitch

Glad you found it.... I was just trying to find a cause... I know sometimes I go off on a tangent... Dave...

Matt Gruber

try opening the hood

K2

Might need a different power valve.

Corbrastang

Try wraping the chrome fuel line on the front of the block with an insulating wrap. Summit sells a velcro type. I had the same problem. What is happening is that you are getting a Vapor lock when the car gets hot and sits. The sheathing doesnt look to bad and you can pull it right off for a show since it is velcro.

Joel 67

I have suffered this problem as well, and it seems to be more pronounced with Fuelies.

Another contributor might be the blend of fuel you have in your tank. In my experience (again, with FI) the winter blend of fuel is more suceptable to heat soak than the summer blends. If you have any old fuel in your tank, it might be worthwhile to drive it out and see if the issue gets better.

FRAC

Is there any chance that it is a compression issue, and when the car has cooled off enough, the oil thickens and it fires off again?

I had this problem too long ago to mention, and that is what the culprit was.

Frac GB