Hot starting problems 3500

Barten

Active Member
My thrusty Rover 3500 1971 has developed a problem when hot. It can take more than 1/2 hour for her to ignite again after a stop. Very inconvenient at petrolstations and other places I choose to stop. I have checked she has spark and also petrol to the carbs. When she is cold she starts and run beutifully. Today I have changed the condenser, that did not make a difference. So I hope you can give me adwise on how to proceed.
Regards, Barten
 
Does your carb to carb fuel pipe loop down low close to the inlet manifold ? If so loosen the unions and have the loop toward the front of the car, higher up.
 
sounds like vapour lock in fuel lines and carbs. is heat shield in place under carb to inlet manifold? have we tried insulating fuel lines as they do pickup a lot of heat once past sump. had quiet a few issues with stalling after stopping poor restoring even with choke! and found was vapour in carbs and fuel line. wondering if our fuel breathing system is OK? modern high ethanol fuel can give significant issues with high temps we get under bonnet. I am now using an in 'tank' fuel additive (metal pellets ). supposedly increasing octane levels. Must admit it does seem to work! have we tried a squirt of fuel directly into air intake when we have this issue ? we may have a weak fuel mixture too? ideally try a Gunsons fuel mixture that check colour of flame in a cylinder. check hot and cold both banks. look at spark plug colours too as good indicator for running rich/lean. an very annoying fault that ought to be solvable.
 
If it also tends to stall when idling in traffic (though we in Australia are more likely to have 30C + days on a regular basis than you will in Norway) it would certainly be fuel vaporisation for which a good fix is changing to an electric fuel pump.
If you already run an electric fuel pump perhaps check that is functioning properly.

Good luck.
 
Hi guys, I have an electric fuel pump in it. I also tested the fuel supply to the carbs, and it was a steady stream. So I am thinking it can be vapor lock within the carburetors ? She has got hs6 carbs, are they more prone to vapor lock than the never hif6 carbs? I shall start by checking the cooling tube that runs through the intake manifold.
regards, Barten
 
Hi, Where is your electric fuel pump situated? If it's down near the mechanical one it could still have vaporised fuel in it, which it can't pump, so the fuel at the carbs is sitting on a 'cushion' of vapour. Either try re-routing the fuel lines away from the heat of the engine ie. not over the bell housing and along the side of the block. Or have the pump at the back of the car so that it's pumping liquid fuel to push the vapour through in front of it.

Colin
 
Hi Colin,
The pump is sitting in front of the engine about where the mech pumps have sat. IT has been there since 2002 and have not
given me problems earlier. And when testing it provided a good flow of petrol to the carb inlet.
 
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