Help - it's conked out 2 days before our hols!

[mr_nunn]

Hello,

After several months of more or less behaving, the van has conked out with impeccable timing just a couple of days before we're meant to be driving to France for our long-awaited holiday on Tuesday..

We were driving around locally on Friday and were going down a hill on a residential street; I put the clutch in and came out of gear...and the van stalled. Since then it won't idle, and can only be kept going by keeping the revs up. At the moment I can get it running by screwing out the dashpot to keep it above idle, but this is just a sticking plaster really.

We had this problem before and it was the carbs so I've had them out, checked for crud, cleaned up and blown through with air. Checked the pilot and air cutoff solenoids and they're clicking and screwed in tight. Linkages all seem ok; needle valves (not long ago replaced) seem fine; checked the nuts around the inlet manifold, put everything back... still the same. The carbs were tuned just a few weeks ago by Campershack. I wondered if the idle speed screw had gone out of adjustment but even turning this out, it is impossible to get the revs up enough to hold idle; it seems bogged down at around 500rpm.
I've checked the timing and it's spot on at 5degATDC with everything connected.

I have looked around the pipe work and can't find any air leaks.

Then I came to the ignition system. Pulling the leads, they all seem to sparking. I haven't yet checked/changed the spark plugs. But I checked the coil (early) and finally found a possible problem: the resistances measure as 3.8Ohms and 8.2kOhms; Haynes says it should be (0.52-0.76) and (2.4-3.5k).

So could it be the coil causing the problem?

(Incidentally, the van has recently been taking a few goes to get started... so I am now wondering if this might have been a dying coil??)

Or any other ideas please? Help save our holiday my kids are desperate to use their passports for the first time!!

Thanks

[scottbott]

have you checked the 'cone' shaped filter in the carb body?,they can crud up quite a bit

[mr_nunn]

Thanks - yeah carbs have been out and de-crudded and fuel seems to be getting in..so thinking this time maybe it isn't the carbs..

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[bigherb]

I take it you still have the standard Solex carbs?
Then check the two idle solenoids and cut off solenoid are working.
Switch the ignition on then remove the wire the solenoids should have an audible click when you disconnect and reconnect the wires.

And yes if you still have the original electronic ignition you have the wrong coil.

[StefG]

I had a similar problem a couple of years ago. Manifesting itself with all the symptoms as fuel starvation at low revs/ idle. It turned out to be weak spark due to failing leads and plugs. Did you know that wbx will run on 2 cylinders quite smoothly? Solution for me was plugs, leads, cap and arm. Worth a try

[mr_nunn]

Thanks for the replies so far.

BH, yes it's the standard Solex carbs but I have already checked the two idle solenoids and they're clicking consistently and seem fine.

I will try a new coil, new plugs and check the leads/cap/arm.

[bigherb]

I have already checked the two idle solenoids and they're clicking consistently and seem fine.

What about the bypass solenoid?

Then remove the idle solenoids and check the end hole in the nozzle is not blocked.

[mr_nunn]

Thanks Herb, yes checked all 3 solenoids and had the 2 pilot ones out to check the ends too. And when i get the engine running by increasing the revs with the dashpot, disconnecting either pilot cutoff solenoid kills the engine suggesting they are both allowing fuel through when connected...

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[ajsimmo]

Is the plunger in the idle cutoff solenoid actually opening? With the air hose pulled off the top you should hear it sucking quite loudly at idle. If it's not opening it won't suck and would give exactly the symptoms you describe.

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[mr_nunn]

Thanks Andrew. Bur yep the idle air circuit is definitely hissing loudly...

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[ajsimmo]

Then it may be the idle fuel screw is blocked. Try squirting a little carb cleaner or brake cleaner into the idle air intake and see if the revs pick up.

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[mr_nunn]

Thanks Andrew I'll try that, i didn't take the screws out when cleaning up the carb so as not to mess up the tuning, so it could be blocked i guess. Will try your carb cleaner check when i get back (am currently out on a mission to get a coil)...

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[mr_nunn]

I think the holiday is saved!

Thanks to everyone for the replies.

Andrew, I think you nailed it - I did your test with the carb cleaner and the revs picked up like you said. So I took the LH carb off again, and took both the idle mixture and speed screws completely out, and the air bypass solenoid, and blasted everything with air, and then put it back together, and this time it seems to be back to normal. Phew! Next time the van is with you in Grantham take a large beer out the fridge as I owe you one!!

The only annoyance was that I spent half the day driving to the JK warehouse and back to get an emergency coil, which wasn't the problem after all... but I guess if my coil is dodgy/the wrong one then it may be worth changing it anyway... though I might leave that till we get back as I am reluctant to rock the boat now it's behaving again.

Thanks again to everyone for helping - it's really appreciated; what a great forum.

Krishnan

[ajsimmo]

Great news! Glad to help, Krishnan. Have a fantastic holiday.