Volvo 240 with a weak spark, won't run! Help please :)

[DW42]

A quick look at the Bosch online catalog shows that the coils have different part numbers: 940 B230FK coil part number: 0 221 118 351; 240 B200E 0 221 122 334.

If changing the coil doesn't fix the weak spark, the ignition module would be the next potential culprit, as julianps's experience suggests. If this failed I would be surprised that the engine would run at all, as it controls the spark timing. Maybe someone on this forum has experience with this?

[Bugjam1999]

ok, thanks for that...

bought a second hand coil from someone here on the forum, easy way of testing if it's at fault.

I think the rotor and distributor cap could be replaced at the same time, does anyone have a recommendation of a volvo parts supplier? i've been using a local motor spares place, but it's not like i'm especially loyal to them...

thanks,

Bugjam

[Antz]

Your local dealer is the best parts suopplier for your Volvo.

Theya rent like Ford who bin everything after 10 years and charge you a fortune for motorfactor grade aprts.

Volvo stuff is very good and even now, they can get a good 90% of everything for a 240. The way they see it is, if the cars are on the road then they ened spares and they can supply them.

[Bugjam1999]

Ok, home for the weekend and have been doing some tinkering.

Spark from coil is yellow, but appears strong... replacement 2nd hand coil hasn't arrived yet, so can't swap that out to test it.

Spark after the distributor is same strength as spark off the coil, so i don't think the distributor is at fault.

Hot wired both pumps and both make noise - in tank pump is much more distinctive pump noise than the main pump, but the main pump is buried more than the in tank pump... presume it wouldn't make any noise if it wasn't working?

fuel pump relay closes.

Interesitng bit - the car starts and runs for a few seconds and appears to run fine, then it cuts out and no amount of churning it over will get it to start again. But, leave it for a few minutes and it'll start for a few seconds and quit again. Because it appears to run fine when it's running for those few seconds, i'm leaning towards thinking the ignition system is fine and the fuel system is at fault? it had exactly the same symptoms a while back when i was working on the car and tried to start it forgetting i'd removed the fuel pump relay.

Assuming that the fuel system is at fault, i'll follow the instructions of Julianps and measure the flow rate of the fuel tomorrow as a first step.

I presume that if i remove the leads to the coil (so that the ignition system is completely de-energised) and then disconnect the fuel line after the filer, i can measure the flow rate of fuel to the engine and check that the electrical system to run the pumps is working as intended in one go?

Thanks again for help so far...

Bugjam

[Antz]

Coil it on its way. Fear not Went in the post yesterday

[Bugjam1999]

Cool, thanks

Will tinker tomorrow, looking at the fuel system to start with, and report back.

Bugjam

[Bugjam1999]

Ok, where's the instructions for hot to hotwaire the pumps again...? I can't find them on the net - lots of posts say things like 'hotwire the pumps' but I can't find the actual instructions.

Something like fuse 3 and 6... err...

Thanks

[Bugjam1999]

and of course then i find it...

http://cleanflametrap.com/transferPump.htm

[Bugjam1999]

Ok, some more tinkering.

Hotwire both pumps and the car doesn't run- same as before.

Hotwire both pumps and after the filter produces nearly 600ml in 15 seconds- looks clean.

Hotwire both pumps and at the union in front of the wiper in the return line produces 200ml in 15 seconds...?! Did this twice to make sure I wasn't doing it incorrectly.

Not sure what the solid return line within the filler cap is. There's the filler neck and then there's a little drain hole in the bottom of the filler neck rubber surround. Can't produce sounds of bubbles by blow

[Bugjam1999]

... Damn phone...

By blowing down this hole, but not sure where that goes anyway? I thought that was just an overflow drain to the floor in case fuel was spilt whilst withdrawing the petrol pump after filling.

Not sure how to progress... Suggestions?

Thanks,

Bugjam