Club 80-90 Forums

I know the 'stalling at idle' question has been done to death but .....

.... I have a situation where, once engine is warmed up so its off the choke, the engine will stall at idle;
But, here is the odd thing; if I restart without touching the throttle it will idle nicely but as soon as I touch the throttle, then let the revs die down again it stalls; start up with no throttle and it's nice again, dab the throttle and the engine revs (as you'd expect) then as the revs die away again it stalls;
Anyone got any ideas??
What would be the difference in the carb state (assuming it's carb related) between a start with no throttle, and the state after the throttle has been slightly opened, then closed again (ie a dab of throttle)??

(This situation just happened again while I was out just now and eventually, after me sitting in a carpark playing around with different starting, throttle ideas, it self-healed and ran just fine all the way home - so it's an intermittent problem (which doesn't make it any easier to solve)?!?)

Ideas?
Tests?

Could just be a sticky throttle thats set a bit too low on the throttle stop screw.

try starting then in engine bay push throttle home to the stop ( not open)

I suppose air leak may also do it, lean on revs falling more likely to stall than lean on steady idle.

Thanks - interesting thoughts.
I would have assumed it was a vacuum leak somewhere but it seems to be intermittent and varies on that throttle blip which would suggest that it's something else - although I like your idea that decaying revs are more likely to 'stall' than steady revs ....... don't understand it ..... but like the idea!!

I would check the throttle stop screw also, but it could also be an idle mixture... I only say that because I fixed a similar problem on an old mini that way. If I just gave the mini a gentle quick rev at idle as it settled to idle it would drop just below tick over speed, however, if cold it used to drop a bit too low before settling and stall or almost stall!

dunno if that made sense? Anyway, give the card a bit of a clean and the van decent blast. Might sort it out!

Timing is also on the move when you blip the throttle, the vacuum advance is reduced if it's working.
do you know what your idle revs are?

itchyfeet wrote:Timing is also on the move when you blip the throttle, the vacuum advance is reduced if it's working.
do you know what your idle revs are?

Nope - don't have a rev counter unfortunately
But when I blip the throttle (which makes it stall) I'm giving it the lightest touch so can't imagine that timing would move much if at all???

Smosh wrote:Anyway, give the card a bit of a clean and the van decent blast. Might sort it out!

The rest of your post made sense - but I don't understand this bit - did your spellcheck go crazy?!?!

Haha! I was meant to say give the carb a clean and take the van for a blast. I.e. drive the van and once warm Sit at mid to high revs for a few minutes, accelerate hard up through the gears. I'm not convinced where that actually helps, but living on a small island the van is always better after a nice run in the UK!

If you have a fancy multimeter you can do it in the from the engine bay. Someone else will have to explain that though, I can never remember which wire to connect to!

Smosh wrote:Anyway, give the card a bit of a clean and the van decent blast. Might sort it out!

Well, I gave the card a bit of a clean and the van decent blast and it all seems to be ok at the moment - possibly just a bit of dirt/debris in the idle systems but only time will tell!! I'm holding my breath - thanks for the ideas/advice everyone (however cryptic!!)

It read like a blocked idle jet to me too.
A partially functioning anti dieseling valve will have the same effect

kevtherev wrote:It read like a blocked idle jet to me too.
A partially functioning anti dieseling valve will have the same effect

Yeah - I thought I'd got it sussed at one point when I discovered that the wiring to the anti-dieseling valve was pretty dodgy (old partially broken wiring) but I repaired that and the problem didn't seem to go away ....

MidLifeCrisis wrote:

kevtherev wrote:It read like a blocked idle jet to me too.
A partially functioning anti dieseling valve will have the same effect l

Yeah - I thought I'd got it sussed at one point when I discovered that the wiring to the anti-dieseling valve was pretty dodgy (old partially broken wiring) but I repaired that and the problem didn't seem to go away ....

ok at least you eliminated it

kevtherev wrote:

MidLifeCrisis wrote:

kevtherev wrote:It read like a blocked idle jet to me too.
A partially functioning anti dieseling valve will have the same effect l

Yeah - I thought I'd got it sussed at one point when I discovered that the wiring to the anti-dieseling valve was pretty dodgy (old partially broken wiring) but I repaired that and the problem didn't seem to go away ....

ok at least you eliminated it

Well - I eliminated the last several inches where it separates out to feed the coolant temp switch and then the idle-cutoff solenoid - I suppose it could be dodgy in the single wire that runs from there into the black box of tricks - but that seems healthier (it's in a plastic ducting for a start!!

Have a feeling this one will return in the future!! Fingers crossed (that it won't)

MidLifeCrisis wrote:

Smosh wrote:Anyway, give the card a bit of a clean and the van decent blast. Might sort it out!

Well, I gave the card a bit of a clean and the van decent blast and it all seems to be ok at the moment - possibly just a bit of dirt/debris in the idle systems but only time will tell!! I'm holding my breath - thanks for the ideas/advice everyone (however cryptic!!)

You saying my advice wasn't clear and concise? Haha! Pleased it is sorted, may be worth scheduling in a proper carb clean down the line!