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two cylinder delight - intermittent
aggri1 - April 1st, 2004 at 10:34 AM

Well, I thought I had figured the problem out, but evidently I either got it wrong or replaced a faulty part with an identical faulty part.

Every now and then, usually only once per drive, but almost with 100% regularity after getting fuel (after a few minutes), my poor old blue bus suddenly slows down. It feels like the driver just stepped off the accelerator completely and suddenly, when he/she did no such thing. The engine runs extremely rough and kombi has very little energy - she can't get above 40 usually, on the flat!

I normally 'fix' the problem by shutting the engine off. After a moment start it up again. Sometimes this fixes it straight away, other times I repeat the procedure several times. After that she's great again.

Now a volksy mech in Springvale (VIC) told me that it was likely the cut-off valve on one carby. This seemed reasonable - during playing up, two cylinders weren't working, but _were_ sparking. So those two weren't getting fuel thanks to the silly cut-off-valve cutting off. Seemed reasonable, although why they put such a valve on, I can't imagine - and only on one carby? Why oh why?

Anyway, I thought I knew which one (valve) the mech was talking about - on the carby, there are three electrical leads, and he meant the one closest to the front of the car right? Right?!! Well, I found another 1800 motor, and pillaged that little valve from it's carby, and put it on mine. "That'll fix her. How do you feel now old girl?"

Evidently she didn't feel better. :-( Yesterday after getting fuel (BP Premium of course), she did the same as she always does after getting fuel: couple of minutes OK, then splutter-splutter-sloww..... And I only got 3litres, as the fuel stopped coming out after that - apparently they'd run out (ooh, hope I didn't get a whole lot of bottom-of-the-barrel crud).

Well, if someone could tell me I'm incompetent, that I changed the wrong thing, I'd be grateful; or, if you've heard of similar problems, then too.

Oh man, well, she's always fun to drive, that's for sure.

Cheers,
Aurel.


modulus - April 1st, 2004 at 11:19 AM

If your diagnostic tests are accurate, then you might want to look at how you fuel cap seals. You might be trying to pull a vacuum in the tank, due to lack of breathing (especially difficult after filling up, and will solve itself with a five-minute rest, as air slowly leaks into the tank).

hth


AdrianH - April 1st, 2004 at 11:48 AM

The cut off valve is the idle jet right ?, it was designed to prevent over run, as soon as there is no power the little ball inside stops any fuel flow. If you pull that jet/valve out and hook it up to a 12v power supply there should be an audible click, no click then its knackered. Also check your wiring, gets a bit crusty in the engine bay, might be a dry joint.

The only other thing you should do is check your fuel lines, make sure they arent close to any sources of heat, this does strange things sometimes.


aggri1 - April 1st, 2004 at 04:09 PM

Yeah, I'll check and see if I get a click.

Hot fuel lines hey? Well, come to think of it, one line DOES go from the pump up to the t-piece right in front of a piece of tin/ducting which is not in place correctly - and what's behind there? The cylider heads! Hmm, I guess I could look into that also. But then, why would two cylinders work OK (the ones on the side with the "weeny" carby).

Thanks folks
Aurel.


Che Castro - April 2nd, 2004 at 12:24 PM

like others said check the fuel cutoff solenoids.

If fuel gets too hot it tends to boil and vapourise which is what is known as vapour lock. This tends to happen after driving for a while and then trying to start again after a while.

Check that too - its also a fire danger to have fuel so close to heat


aggri1 - April 14th, 2004 at 03:18 PM

The little cut-off thing makes a click OK. The original one that's now no longer in the car slides it's little stem in and out seemingly OK when I give it power. Bummer.

Still chuggin'
Aurel