hot starting

[mountain]

My 1979 240, starts first time every time from cold, runs well, however, if i leave it for 10-15 mins, it is very hard to start, have to crank and crank, until it finally goes.
Had points and plugs replaced a few weeks ago, had problem before that, and if anything it seems worse now,
any pointers for fixing this?

[dingov70]

Does your car have fuel injection or a carburettor ? In both cases , i would suspect that it was fuel pump related . If it is injection it may be possible your injection pump relay is breaking down when hot & not pressurising the system . Another & more likely fault could be cured by simply turning every fuse in the fuse box . Due to the very small contact area of the fuse they ar prone to corrosion affecting current & voltage flow through them .

If you have a carb fitted , it may be possible that the float valve is sticking due to heat & the float bowl has emptied of fuel for that reason . Cleaning the pivot pin for the float & wiping clean the valve face could cure that problem .

Hot starts can usually be traced back to lack of fuel , do you / can you smell fuel when trying to hot start the car ?

Start with these & let us know more if you still have problems


Steve

[Davey240]

I had a 1979 244DL many years ago that was fitted with a carb ( stromberg if memory serves ). I had the same problem for ages and there was an article in the Volvo Driver magazine which described a remedy as i think it was a common problem at the time. Basically it was due to the fuel vapourizing when the engine was warm resulting in difficult starting. The remedy was to take a length of 8mm copper pipe which was connected through the plastic air intake pipe and into an existing hole in the side of the carb. The other end was just taken down into the engine bay and vented to air. Once i did this i never had a problem again. Hope this helps and sorry if my description is a bit vague but it was 27 years ago. Cheers Dave

[140]

I seem to remember a problem on the 79 model year carburettor with hot starting. The factory fitted a small pipe from a connection inside the plastic air filter pipe face plate which ran inside the air filter pipe to the bottom of the air filter. However this small pipe softened after a short while and fell off and in a few cases was sucked into the carb and jammed the piston and butterfly open. A factory service bulletin was issued to drill though the rubber pipe and plastic connection and fit a split pin.
I would take a look and check whether the small pipe is there.

[CaptainAhab]

If this is a Pierburg carb (or similar) there is a hot start valve on the engine bay bulkhead. If this is faulty or has lost it's 12v supply it may be the culprit.

See yellow circled item in picture.

[mountain]

thanks for all the suggestions,
will look at them soon, its a little embarrassing having to crank and crank and crank, esp when the car goes so well otherwise.