Hot starting problem

[dandman]

Hi all ,
Am having a little issue with my b20 122 s . no problem starting in the morning, dont have to use the choke .but if after driving say 20 mins i stop and turn off the ignition the engine gives a couple of chugs before it dies . trying to start it when hot is fingers crossed time .turns over no problem ,might give a half hearted attempt to tease me and keep my hopes up but to no avail . at this stage i sulk , walk away and come back in 10 mins and it starts. would appreciate any help .
thanks
DAN

[ClassicVolvoShop]

- Fuel settings on carburettors are too fat..
- Leaking manifold?
- Heat shields?
- Ignition timing?
- ?
It's really a very open question - there can be 200 reasons - so a lot more symptoms and data is needed for a closer diagnose.. Sorry, but that's just fact..

[AidanC]

Have a look at the colour of your spark plugs - it'll give you some insight into whether its running too rich or not - if they're sooty you might need to lean the mixture properly and maybe check that you've got the right needles fitted. Also worth checking the workings of your choke cable to make sure that its not stuck partially on. The car shouldn't really start from cold without choke so its probably the area to look at first.

Are you happy that the timing's right? If its too advanced then the car'll start more easily when cold but you'll end up with other issues.

Probably no harm to give it a methodical checkup, through points, timing, mixture etc.

As CVS says, is the carb heatshield in place?

[dandman]

thanks for your suggestions , will work on them during the week .
DAN.

[tdz840]

Hi all ,
Am having a little issue with my b20 122 s . no problem starting in the morning, dont have to use the choke .but if after driving say 20 mins i stop and turn off the ignition the engine gives a couple of chugs before it dies . trying to start it when hot is fingers crossed time .turns over no problem ,might give a half hearted attempt to tease me and keep my hopes up but to no avail . at this stage i sulk , walk away and come back in 10 mins and it starts. would appreciate any help .
thanks
DAN

Sounds like you are running too rich especially as you dont need choke from cold. Perhaps the choke linkage isnt set up but more likely the mixture.
try lifting the carb piston pins about 3-4mm together and you should hear the engine rise then settle (once warm and no choke). If it dies straight away you are too lean and if it rises considerably then you are too rich.
HTH
All the details are in the Haynes and self explanatory
Russ

[dandman]

Many thanks russ ,had a chance to check the choke cables and they appear to be right .started up only to discover the oil light refused to go off . Any idea of the location of the oil pressure switch, i cant locate it . I hope thats all that is wrong .

[222s]

The oil pressure switch is on the side of the block, behind the exhaust downpipe. They do go wrong - the last two on my car have only lasted about three years each....

[tdz840]

Many thanks russ ,had a chance to check the choke cables and they appear to be right .started up only to discover the oil light refused to go off . Any idea of the location of the oil pressure switch, i cant locate it . I hope thats all that is wrong .


You should find the oil pressure switch behind the exhaust manifold about 2'o'clock to the oil filter.
Bit awkward to get at and obviously only when the engine is cold!
Russ

[Ron Kwas]

Dan;

Carburated vintage Volvos are pretty cold-blooded beasts which don't start easily after a hot-soak...and with even more difficulty if you are not using the "Hot Start Procedure" ...paraphrasing from owners manual: Depress throttle to the floor (no choke!), crank until motor starts, then modulate throttle to clear, and let idle.

Checking your mixture can't hurt, but please try the procedure, and report back on your results. Many owners are just not aware of it...

Cheers from Connecticut!

[Derek UK]

If the engine IS in a good state of tune i.e. plugs, points, timing, carb balance, mixture, tappets etc, the engine will, should, hot start with just a turn of they key. Just reaching through the window and clicking the key over should start it. If you can train yourself NOT to touch the throttle at all as you go to start the car when hot it will be the same thing. Stomping up and down on the pedal does very little with SU's and Strombergs as they have no accelerator pump, unlike the Zenith on the early B18A.
As Ron says, foot to the floor and bring it back up as it catches, works, but is often accompanied by lots of revs etc. Not cool! It's the procedure used when trying to start a flooded engine so not really a "normal" method IMO.

[dandman]

Thanks Derek for the help. it was a procedure i was unaware of. i found it on one of your old threads last night and have used it today on a couple of occasions and it worked perfectly .learning as i go along . thanks again
DAN