Hard Starting When Hot?

Fred A

Fred A

Well-known member
Still driving my '47 while waiting to fix other problems but as the weather heats up the engine can't be left idling or it will die. As it gets hot it may stumble and barely start by three guys pushing. When turned off hot it doesn't want to restart. When cold in the morning below 60 degrees, the Holley 92(yes on a 239) will not need any choke to start immediately from idle position and will not die if the throttle is tickled to keep it going, again without choke, until it is warmed up some. I earlier had trouble with a bad repop condenser and the present one is from a 6v Porsche, 30 years old, probably VW. On the long list of needed fixes, the right carb is there but the new 92 serves temporarily. Still have not had the distributor done. Seems like enrichment problems. The power valve on the 92 is ancient however new. Is it originally under a 7? Think I'' get out the books. Any Ideas? Fred A
 
Have you tried replacing the coil? If you had a known good coil you could use temporarily,it would solve or eliminate that problem possibly.
 
Coil is New

This latest stall on the street, preceded by rough acceleration, the engine then stumbled and quit, then no start. But it gets pretty hot to the feel, and after cooling off some, the car starts again. This is the third coil in a month, mostly trying to get a correct looking coil that won't ooze brown tar, but this is a conventional cylindrical one, from CW Moss with no resistor specified like for a Model A. The weather is only going to get hotter and coils are suspect when it warms up. I need to take along my infrared thermometer to check. Doesn't need to be calibrated to give good relative readings. The transitition from seldom driven to often stirs up rust from the tank, but having gone through a couple of tanks, it's time to empty the sediment bowl and look again at the ignition. Thanks: Fred A
 
Maybe check fuel delivery. I had trouble with a new fuel pump on a 36. I was not able to find the problem with a vacume/pressure guage. I ultimately waited for the engine to die, and then hooked up a special can I made. It was a metal brake fluid can with a hook welded to one side, and a hole drilled in the bottom with a piece of metal line welded to the hole to form a spout on which a flexible line could be attatched. The can hung from the radiator suport rod, and the piece of flexible fuel line ran from the can to the carb. I made a short stump end peice of metal fuel line to screw into the brass fitting.

The engine ran, got hot, and died. I filled the can with gas, and the engine started right up and ran as long as there was gas in the can. I put a kit in another fuel pump I had, blew out all the lines, and checked the float and needle valve. I think it was a bad repop fuel pump.

Thanks
 
FRED A .............................
Go with the advice from GM and send your coil to SKIP. That should really fix your problem.
MIKE :)
 
Questions, do you have a 12v conversion? If so, are you using a 12v coil and what is the voltage to the coil after it's warmed up?
 
Fred A said:
Still driving my '47 while waiting to fix other problems but as the weather heats up the engine can't be left idling or it will die. As it gets hot it may stumble and barely start by three guys pushing. When turned off hot it doesn't want to restart. When cold in the morning below 60 degrees, the Holley 92(yes on a 239) will not need any choke to start immediately from idle position and will not die if the throttle is tickled to keep it going, again without choke, until it is warmed up some. I earlier had trouble with a bad repop condenser and the present one is from a 6v Porsche, 30 years old, probably VW. On the long list of needed fixes, the right carb is there but the new 92 serves temporarily. Still have not had the distributor done. Seems like enrichment problems. The power valve on the 92 is ancient however new. Is it originally under a 7? Think I'' get out the books. Any Ideas? Fred A
Click to expand...
OMO but i think that 92 is a little small for a 239 ci. . Try a #59 with .049 MJ's and a 5.5 power valve and i think you will be a happy camper. ken ct.:)
 
Fred A ............................
You say that you are cooking coils. Do you have that ignition resistor ? Running without a resistor will cook your coil. Did you ever leave your ignition ON, without running, for any length of time ? That too, will cook your coil, if the points happen to be closed.
MIKE :)
 
next time it dies pull a spark plug wire and turn engine over with the starter and see if you have spark at the plug, a bad power valve will leak gas into the manifold and flood engine, also it will drain the carb,its also possible if your engine is running hot it can boil the gsas out of carb, next time the engine is running look down the venturi so if you you see any gas dripping into the manifold, check spark then fuel for the problem
 
FL&WVMIKE said:
Fred A ............................
You say that you are cooking coils. Do you have that ignition resistor ? Running without a resistor will cook your coil. Did you ever leave your ignition ON, without running, for any length of time ? That too, will cook your coil, if the points happen to be closed.
MIKE :)
Click to expand...

Yeah, this is what I was poking at when asking about voltage to the coil above.
 
Fred,
I certainly agree ,you need one of Skips coils and try a IH 200 condenser. How-
ever if your motor starts on a cold day with no choke you may have an internal fuel
leak in the carburetor....any black exhaust any time or odor of gas?
Charlie ny
 
Went out to Pomona for both days of the LA Roadster show, driving the '47 both days. Mostly for the swap, not for the street rod event that seemed so cool to me 45 years ago. Slickest trick was buying a clutch and flywheel then walking 100ft and dropping them off with Mario the clutch man. I was reluctant to do any tearing down beyond superficial adjustments just to get this event behind me. The clutch work will set me up to be ready. Sure sucked down the fuel at 40 miles each way twice getting under 10 MPG. After turning up the idle and adjusting the idle mix with a vacuum gage, the dying seems to have stopped but still will not start when hot. Makes it tough to fuel up on a hot day. The temp is not however excessive. Years ago I would have hosed down the coil and condenser with refrigerant to isolate problems. Getting that V8-60 carb off of there is very high on the list. As said earlier, that engine is coming out at the end of summer to change heads, clutch and drop the pan for a look. Its a must, couldn't even sell it with a cracked head and chattering clutch, not to mention the lack of reliability. Sure miss the simplicity of the Model As. This car makes me feel retarded. Thanks for the comments which really help. Fred A
 
had trouble with my 40 with 2 Holleys changed to to 97's put a insulator plate under both carbs solve problems in 95 degree heat
 
As In Vapor Lock?

Years ago my '51 Merc' with dual pipes would vapor lock on long grades in summer. The fix was an "Autopulse" fuel pump. I guess sitting on that hot engine could vaporize the fuel and put me out of business, but then upon cooling the pump might need a moment cranking to fill up the bowl again with the fuel pump starting by sucking vapor, not fluid. The pump is a new Chinese/NAPA. It wouldn't be too tough to insulate the fuel lines. Couldn't Houit! I picked up a distributor cap at the roadster show and have a wire set. Jamming wires into that 59A cap is always a buggar. Having to catch up on a bunch of real world chores before wrestling this car anothe round. Thanks again: Fred A
 
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