7 replies to this topic

[SminkyBazzA]

Hello, I think I've done something stupid :/

I have a 93 Rio, 1275, carb, standard electric ignition.

I've had trouble in the past with the engine dying on the M5 (always the M5) in excessively wet weather, easily fixed with a can of WD40 on the hard shoulder but not much fun.

So I bought a can of Holts Damp Start to seal the ignition system, sprayed it around the distributor cap, and both ends of the 5 leads. I was liberal, but not excessive, in my opinion.

I started it immediately afterwards just fine (in hindsight it sounded a bit rough, but it was idling OK), but now this morning it won't stay running for more than a few seconds and is very lumpy before it dies.

I've taken all the leads off, and the distributer cap, replaced the sparks plugs, all with no effect. There doesn't seem to be any sign of sealant where there shouldn't be.

Any thoughts what I've done? Could I have got some sealant inside the distributor? I'm not very knowledgeable about the various parts of it.

Thanks for your help

Barry

[dklawson]

While the application of sealant and the non-starting issue may be related, they also may not be.  It could just be a coincidence.

 

 

Test for spark.  Mark and remove the plug wires (1-2-3-4) and plugs, then put the plugs back in the wires.  Rest the plugs on the engine block and have a friend crank the engine while you watch the plugs for sparks.  After this test remove the center lead from the distributor cap and hold its metal terminal about 3mm from the engine block while a friend turns the engine over on the starter... again, look for a spark between the wire terminal and the engine block.  If you found spark directly at the plugs, the problem could be timing (unlikely) or is fuel related.  If you found no spark at the plugs but did find spark at the disconnected plug wire, look for problems with the cap, rotor, plug wires, and plugs.  If you found no spark at either location, look for problems with the ignition module, coil, and low tension (small wires) supplying the ignition module.  There is always the possibility that the problem is more serious but let's not dive into those until you have made these simple spark tests.

[SminkyBazzA]

Thanks, I'll work my way through these tests when I'm back home on Tuesday (was supposed to be driving the mini up to Staffordshire today).

I did test the sparks using some inline spark testers (between plug and lead, they flash a light), and this seemed fine while the engine was running, though I'll check the plugs directly.

Thanks

[dklawson]

If inline spark checkers showed high-voltage to the plugs... I would not be looking further at ignition problems except to confirm that the the timing is still correct.  Where points are fitted I would consider fitting a new set along with a condenser just to rule out those relatively inexpensive components.

[SminkyBazzA]

Apologies for the delay, turns out it's darker than I thought in the evenings now. I don't have points, so I'll have a go at checking the timing tomorrow evening if my flatmate stays in. I've got a timing lamp, but given how poorly the engine runs (and for only a few seconds at a time), is there anything I should bear in mind?

 

Assuming the timing is OK, what would be next?

 

Thanks for your help!

[jaydee]

Ok you've changed spark plugs, but did you try a different set of HT leads?

Did you spray the stuff over coil connections? If so remove the LT connections and clean them thoroughly.

If still running rough, then move to the ignition module, but do the above first.

[SminkyBazzA]

Thanks for your help dklawson and jaydee, the problem is solved! I replaced the HT leads and distributor cap, but I think the problem was a probably a slightly loose crimp in one of the LT connectors. There was a fair amount of gunk over this, so I guess I either knocked it or the stuff got in there an insulated it. Ran nice and smooth for the whole three hours I drove home this evening :) 

 

Have great weekends!

 

/edit OK, can't pick both answers to mark as solved, sorry

Edited by SminkyBazzA, 25 October 2014 - 12:18 AM.

[dklawson]

That's great news!  Thanks for posting what you found and have a good weekend with lots of driving.