Volvo V6 Hot Starting Problems

[markrolf]

Hi Guys, I'm having problems with our Volvo / GM 4.3V6. Model is 431A (Carb) and it's fitted in a larson san marino (1991).<br /><br />The engine starts very well when cold, but given 5 minutes of warm up it will not restart.<br /><br />Basically, it seems to turn but not fire. The plugs are getting spark. It does seem to turn slower than when cold.<br /><br />I've already replaced spark plugs, leads, cap, rotor, ignition coil and condensor. Timing and gaps are all checked and correct.<br /><br />I'm not sure what else to try, any help would be appreciated.<br /><br />Thanks<br /><br />Mark

 

[Dunaruna]

Re: Volvo V6 Hot Starting Problems

Hi Mark, welcome to iboats!!!!<br /><br />If you are getting a nice clean bluish spark when the motor has warmed up, and it runs o/k when cold - me thinks the choke is is the culprit. may even be time for a carby once over.<br /><br />The "turning slower" points towards a timing issue, but you said that is o/k. What fuel are you running?<br /><br />Aldo

 

[Bondo]

Re: Volvo V6 Hot Starting Problems

Ayuh,.........<br /><br />I Agree with Aldo,......<br /><br />It Sounds like the Carb is Flooding out..... Probably the Choke,... But it Could be time for a General Rebuild of the Carb.......<br /><br />And,.... you might try cutting the timing back a degree or 2 to help it Spin Quicker.........

 

[markrolf]

Re: Volvo V6 Hot Starting Problems

Thanks guys, She starts perfectly from cold and runs perfectly all day! It's just the restart.<br /><br />I was thinking about overhauling the carb anyway. I guess this is the next thing to do so I'll get on with that.<br /><br />Thanks again

 

[Don S]

Re: Volvo V6 Hot Starting Problems

A carb overhaul isn't going to fix the choke. The choke coil on the 431's is electric. If the choke coil is not working, overhauling the carb isn't going to fix it, and if you didn't notice it wasn't working you will have the same problem.<br />To test it, just remove the flame arrestor, and turn the ignition switch to on. The choke should open fully within a minute. If not, make sure you are getting power to it and the ground wire is hooked up. <br />If you read the manual on setting the choke, it will also be way too tight for most summer running. With a cold eng, just turn the choke coil until it just closes (Open throttle just off idle when adjusting).

 

[markrolf]

Re: Volvo V6 Hot Starting Problems

Thanks Don,<br /><br />Understand about the carb overhaul, and will point efforts at the choke!<br /><br />There is only one wire coming off the choke (sorry haven't traced where it goes yet), does it earth through the carb, or should there be another wire connected somewhere?<br /><br />So, when turning the ignition on, I should be able to see the flaps close in the carb? Sorry to be vague, not exactly my expertise!!<br /><br />Cheers,<br /><br />Mark

 

[rodbolt]

Re: Volvo V6 Hot Starting Problems

some choke coils ground through the carb body and others had a seperate ground wire. the key is do you have 12V avalible to the choke coil and does it have a ground path. the choke coil is a bimettalic coil. when you pass a current through it the coil unwinds due to the differing expansion rates of the bi-metaic strip. if the coil opens internally,common, or fails to have a contiuos current path it wont open the choke shutters and creates a difficult to imposible warm restart.<br /> next time you attempt a warm restart look at the choke shutter and note its position.

 

[markrolf]

Re: Volvo V6 Hot Starting Problems

Thanks for that, should be back in the water next weekend so I'll check the positions.<br /><br />Many thanks

 

[Don S]

Re: Volvo V6 Hot Starting Problems

Why don't you fix the problem BEFORE you go to the water ?????<br />On a COLD ENGINE, Remove the flame arrestor and open the throttle about 1/4 throttle, the choke should be closed completely. Without starting the engine, turn the ignition to on (run) position and watch the choke plate. IT should slowly start opening and be fully open after a few minutes.<br />If not, that is why it's so hard to start when the engine is warm. It's flooding.

 

[markrolf]

Re: Volvo V6 Hot Starting Problems

Don,<br /><br />That's exactly the advice I needed. I'll try this as soon as I can get over.<br /><br />Thanks again.<br /><br />Mark

 

[markrolf]

Re: Volvo V6 Hot Starting Problems

Right, I checked this at the weekend. There is current to the choke, but it won't open. I took it off and put power directly to it but nothing.<br /><br />Problem is sourcing a new one. I've tried my local Volvo dealer who tell me it's near impossible to get in the UK. The Volvo part number is 841612. Does anyone have any ideas where I can order one of these from?<br /><br />Thanks for all your help!<br /><br />Mark

 

[cmyers_uk]

Re: Volvo V6 Hot Starting Problems

Yes try , www.volspec.co.uk. They got me one no problem. I also found that in our climate the choke was not needed. I manually adjusted the choke to fully open and it started no problem even when cold and obviously ran fine hot. But then again I only boat during summer.<br /><br />Regards<br /><br />Chris