Distributor?

[davidvincent]

Hi All,

I hope all is well..... We had a motorway breakdown yesterday and after a good few hours spent with the RAC we concluded that a tow truck was in order.

Its our 1980 Petrol 2ltr twin carb van.

The engine failed and then gave a big old backfire, it wouldn't start again although it was really trying. The RAC said the coil and amplifier were operating properly so was probably the dizzy as there was no spark.

Would you guys be inclined to agree? If so would it just be the cap that needs replacing, in your experience?

Many thanks
David

[CovKid]

Impossible to guess Dave. You need to work your way through. Treat it as if the breakdown told you nothing and eliminate each part in turn. I'd check rotor for starters though.

[davidvincent]

Yeah I thought that too, I've never tackled a dizzy before but I've got some books

first of all i need to get home and look up the part numbers i guess, I'd like to know what I'm looking at in the worst case scenario

Thanks
Dave

[VWCamperfan]

Was it coughing and spluttering for a few hundred yards before it finally gave up?

[davidvincent]

Was it coughing and spluttering for a few hundred yards before it finally gave up?

Hi Mark,

Thanks - No, it all happened very quickly, I was moving at about 65mph and it seemed like one big backfire then the dash lit up, what are you thinking?

Dave

[VWCamperfan]

Hall-effect sensor in dizzy. Usually the symptoms of this packing up is a very sluggish misfiring engine that struggles to do anything for about 300 yards and then packs up!
They can go quicker though.....
Here's a test. Get someone to crank over the engine as if you were going to start it on any other day. Now, while its cranking over, unplug the connector on the side of the distributor and plug it back on again. Do this a few times very quickly while the engine is being cranked. If the engine fires into life for just a split second, I would say it's the hall sensor in the distributor.

First thing to check though is probably your HT circuit. Unplug the coil lead from the middle of the dizzy and using something insulated, hold the metal inner of the lead near some metalwork on the engine but not quite touching. Get a willing assistant to turn over engine again and if you have a spark here then it could well be the rotor arm giving you troubles.
Plug it back in and try the same thing but this time with a plug lead pulled off a spark plug. Again, turn over engine and check for a spark. If you have a spark here as well, it could well be a fuel problem but it did die a bit quickly for this!
If you have no spark at the plug leads but have a spark on the coil lead then this is probably a rotor arm problem.
For me it died a bit to quickly to be a distributor cap problem. Those problems normally sneak up on you and get progressively worse!

Have a play and see what you find!

[davidvincent]

Cheers Mark, that is really helpfull, I'll crack on!

[davidvincent]

Hall-effect sensor in dizzy. Usually the symptoms of this packing up is a very sluggish misfiring engine that struggles to do anything for about 300 yards and then packs up!
They can go quicker though.....
Here's a test....

Hi again,

Ok - so I did the test with the lead on the side of the dizzy - pulling it on and off, this seemed to make no difference so I moved on.

I couldn't get any spark at all from the coil lead. On the off chance I popped in to volkspares and picked up a cap and rotor arm - they seemed to make no difference either (although the new rotor is a lot smaller than the old one - I wonder if the old one was the rev limiter type??)

So I'm thinking perhaps a new coil? And perhaps a new spark amplifier thing attached to the engine bay wall (forget the actual name??) and HT leads as I just managed to snap 2 of mine! cant have been very good quality I guess!

Aaargg, I hate it when a plan doesn't come together.

Dave

[davidvincent]

I also just realised that the tail pipe is now hanging on for dear life! Must have happened when it backfired on the motorway

[VWCamperfan]

I had a backbox open up on me like an old tin of beans when mine was backfiring due to carb problems!
A good test for HT leads is to try to hold them upright... Like the ol' Indian rope trick. If you can then its time to get new ones! The old ones have gone hard and will be breaking down.
Your plan will come together. Just depends on what letter of the alphabet your plan stops on... Plan A, Plan B, Plan...
Good luck tracking it down too.

[davidvincent]

Ha ha, I know - I get the feeling that the plan may need a few new letters adding, just to be safe

[VWCamperfan]

Just having another look through the posts here and noticed nothing has been mentioned about the idle stabilizing unit. Have you tried unplugging the two round connectors from underneath it and then connecting them together? Could be a problem with that with any luck.

[davidvincent]

Just having another look through the posts here and noticed nothing has been mentioned about the idle stabilizing unit. Have you tried unplugging the two round connectors from underneath it and then connecting them together? Could be a problem with that with any luck.

well I was thinking about that - I wasn't sure what those two connectors actually did, if i disconnect them what should I hope for?

Dve

[VWCamperfan]

You have to disconnect them and then plug them together, bypassing the idle stabilising unit. If you leave them apart then engine won't start (even if it could!).
Hopefully if thats the problem it will fire into life!