engine cuts out when i slow down or idle.

[djhammy]

Engine cuts out when i slow down or idle.

HI Folks this is an old problem i have asked about before but i thought it had solved it's self.

A few months back i was about to buy a new carb as it looked like the throttle spindles were leaking in air. All of a sudden the engine started running perfectly again and that's been the case for a long while until today that is and the problem is back again.
This has happened a few times now and it's driving me nuts!! it runs terrible and then it suddenly fixes its' self. I can't go on like this so do i bite the bullet and get another webber 1889090700. The bizzare thing is i purchased the same carb from JK around 3 years back so it shouldn't wear that quickly but when WD 40 is sprayed on the throttle spindle the engine pick up? I'm totally baffled. Could it be plugging itself buy sucking dirt in the leak??

Must say also i realise i can send the current carb off to sorted but i need my van to work so that's why i am looking at a replacement so it can be quickly swapped over and hopefully i'm back in business.

I need a stiff whiskey.

Cheers

Dave.

[CovKid]

Its not throttle flap wear if its not a consistent problem although that may contribute. Don't swap to a Webber either - better to find the fault. The dying at idle is likely to be muck ending up in your carb, a clogged air or fuel filter or an intermittent air leak via a gasket.

You need to start by checking and if required, cleaning the carb out and make sure that no parts of the fuel delivery after the fuel filter are breaking down (ie the inside of hoses), sending bits into the float chamber. If the fuel lines are old, replace them.

If you were a bit nearer, I'd come and sort it for you but consider the things I've suggested and you should nail it. You may still have throttle wear but this may not be causing the bulk of your problems. If air filter hasn't been changed in a long while, DO change it. I had similar symptoms and it turned out the air filter was so clogged, the engine was effectively sucking through a straw - oxygen starvation.

For the engine to run satisfactorily it needs a predictable and predetermined air/fuel mixture at varying throttle openings, any degredation will impact on idling. Too little air (oxygen starvation) and it won't idle, too much air (leaks) and it won't idle. Weak mixture (ie carb settings) will also cause poor or non existent idling, but NEVER touch the mixture screws until all other avenues have been explored - particularly if sometimes it runs fine.

[djhammy]

HI Cov cheers for excellent advice as always.

Yes it's cutting out the minute i start slowing down or idle. I have to keep the revs up or thats it. Last two times this has gone on for a week or two and then hey ho just like magic it suddenly works fine again. it has then be fine for a month or so and then it just happens again. I had noticed a slight loss of performance in the past week it had been noticeably more sluggish. As i say had been running better than i can ever remember so if it was the throttle spindle surely it would be all of the time but hence my theory it was plugging it's own leak..
I already have a Webber conversion in place i replaced my old Pierburg with it that's why i was looking a a new Webber as it would be a straight forward swap.
When running it sort of dies on every 4th stroke if you get my drift then whirs along then dips again.

Any way shall get to work and thanks.
Dave

[djhammy]

HI Cov just sprayed the carb with carb cleaner to see if that makes any difference before i take it any further. Hasn't yet. The air filter was pretty dirty but if that was the reason am i right in thinking when i ran the engine with the carb cover off it would then run properly again?
Cheers

Dave

[CovKid]

Yes if filter was clogged and you ran without and it still won't idle, its not the air filter. Is the fuel shut-off valve (if it has one) connected and working? Is there any much in bottom of float chamber?

[djhammy]

HI Cov is the fuel cut of valve the solenoid the gold covered part bottom right of this photo of the carb.

I have heard this isn't actually used any more on the newest version of this carb as it's caused problems.

http://www.justkampers.com/shop/type_25 ... 13646.html" onclick="window.open(this.href);return false;

[CovKid]

Thats the one. It shuts off fuel when theres no power to it. Try connecting to a live 12v in engine bay - may just sort your problem

[djhammy]

Cheers i'll try that after dinner. Is strange they don't have this now on the carb. Wonder if it had been a problem?

[CovKid]

They may not have it on more recent models, allowing fuel straight through but if yours actually has one fitted, it needs wiring up.

[djhammy]

HI Cov definitely electric signal in the red lead attached to the solenoid. I don't seem to get any clicking noise others speak about though. The solenoid was loose so unscrewed it to check its condition. The plunger moved freely so I put it back in and ran it plugged in and unplugged. Didn't make any difference.
Of course it could be its getting the signal but not working though would i get any fuel through if it wasn't opening to let fuel through?
I suppose its a strip down now.
The braded hose to the servo looks well frayed so i'll try and replace that though i believe they are difficult to get.

Hope you had a good weekend.