Why are both my series 2 trucks hard to start hot??

[1961 109 WAGON]

Both trucks. One with a solex the others a zenith. Starts perfect when cold. Once the engine gets hot they both seem to vapor lock and takes around ten seconds of cranking before they will fire.. Any ideas???

[I Leak Oil]

How about your fuel lines? Are they routed in a way that keeps them warm or cool? How's your timing? Any smoke on start up? Color?

[tmckeon88]

It might be a vapor lock issue, which I had on my series IIA a few years ago. I drilled a couple of holes in the underside of the gas cap to allow air to get into gas tank as it emptied, and it cleared right up. In the meantime, when it's hard to start maybe just loosen the gas cap to allow air in.

The holes were drilled on the inside, not all the way through the cap.

Good luck.

Tom

[1961 109 WAGON]

The fuel line is routed just like they came from the factory. I timed both trucks a year ago. And they were in spec when I checked them. And no smoke upon start up.
I will try the gas cap trick as well thanks!!

[73series88]

Mine does the exact same thing
Aaron

[mongoswede]

You might try running heavier battery and ground cables to help boost the cranking speed. You might try putting a check valve in the fuel line just before the carb to keep fuel from draining back. Also you could try insulating the fuel line.


I should have also mentioned that the better battery cables can improve spark performance. You could also install a hotter coil....are you running points or electronic ignition?

[bkreutz]

Mine's done this for a long time, I figured it was fuel peculating over into the intake putting it in a flooded condition, I'm too lazy to fix it so I just put the gas pedal to the floor when it's a hot restart situation (and keep it there) while I'm cranking, fires right up. I'd call myself a procrastinator but I don't want to rush into anything so I'll make that decision later.

[yorker]

6.2.2 Hot Operation
When gasoline vaporises prematurely in the fuel system, i.e., upstream of the
carburettor jets or fuel injectors, operability problems may occur. The
likelihood of the gasoline vaporising will depend on engine design, ambient
temperature, ambient pressure and fuel volatility. Due to the higher vapour
pressure of ethanol-blended fuels, the incidence of vapour formation in the
fuel system is more likely than for gasoline fuels. http://www.environment.gov.au/atmosphere/fuelquality/publications/review-non-automotive/pubs/review.pdf

[1961 109 WAGON]

I'm running points on both trucks.

[antichrist]

I should have also mentioned that the better battery cables can improve spark performance.Not unless the existing ones are in really crappy condition, to the point of the engine not cranking.