Engine now wont idle!!

[chris71920]

Im running a Weber carb and its been fine the whole time Ive had the truck, but after playing about in the mud today it just will not idle!

Ive tried turning the speed up a little and cleaning out ICV valve but if I let my foot off for more than 3 seconds it just dies. Doesnt matter if its @ 1k rpm or 2k rpm. Ive checked all the obvious things but nothing helps
Could it be an ignition problem instead? Or muddy dirty coil? The distributor is free from moisture inside and I sprayed WD over the leads etc It seems pretty chuggy now too and wont hold a smooth rpm even keeping the throttle steady.

[ScottieJ]

Maybe try changing the fuel filter? is it the first time you've taken it offroad? Might've shacken up any crap that was in the bottom of the fuel tank and blocked it?

Is it definetly firing on all 4 cylinders? While its running with some insulated pliers remove a single ht lead at a time and listen to see if it changes how the engine is running, if when you remove a certain lead nothing changes then you have a duff lead.

[chris71920]

The first proper time off road yes, only done a bit of green laning up until then.

It drives fine and revs up as normal, it just trys to drop off a couple of seconds after it starts to idle. It could be a lead, I'll try them in the way you said.

[ScottieJ]

Not sure if webers have a fuel stop solenoid, if so check that this still has power and is working, I've had the earth break on mine before causing the same sort of problem, the carb could get enough fuel through when revving but as soon as it drops to idle it cut out.

[Edweird]

Not sure if webers have a fuel stop solenoid, if so check that this still has power and is working, I've had the earth break on mine before causing the same sort of problem, the carb could get enough fuel through when revving but as soon as it drops to idle it cut out.

Speaking of fuel stop solenoids, when I unplug mine, nothing happens.

[ScottieJ]

It obviously doesn't work then

[Edweird]

It obviously doesn't work then

Aye, but apparently the solenoid cuts the fuel on over-run, which would be nice. Sill, at least it hasn't jammed the other way and permanently cut the fuel off.

[chris71920]

Come to think of it, I'm sure I noticed it backfiring from the exhaust on the way home several times when on overrun :s

[ScottieJ]

It obviously doesn't work then

Aye, but apparently the solenoid cuts the fuel on over-run, which would be nice. Sill, at least it hasn't jammed the other way and permanently cut the fuel off.

I could be wrong but I'm not sure that it does on UK carb'd SJs it just has a constant live feed from the ignition, it would need something to cut the power to shut it down to stop the fuel, on US models it is controlled by the ecm that they have fitted for emissions.

[Edweird]

It obviously doesn't work then

Aye, but apparently the solenoid cuts the fuel on over-run, which would be nice. Sill, at least it hasn't jammed the other way and permanently cut the fuel off.

I could be wrong but I'm not sure that it does on UK carb'd SJs it just has a constant live feed from the ignition, it would need something to cut the power to shut it down to stop the fuel, on US models it is controlled by the ecm that they have fitted for emissions.

Oh, well that's alright then.

If it's firing in the exhaust, that would tell me you've got a dead cylinder that is letting fuel and air into the exhaust.