lights and idling problems

[ermie571]

ok, 2.1 running carb and LPG.

initial problem - running on three cylinders. Fixed by replacement leads. Now running on four.
Starts on the key in the morning, idling on choke at 1000 or just over. Then the peculiarities start as the choke comes off.
No draw (radio off, wipers off etc etc) and it is more likely to idle at 800 revs. But at night, with the lights and the wipers off, pull up to a halt, and it mainly will try and idle, and then drop away. I can turn things off, and the idle MAY creep up.
BUT>>only requires the lightest of tickles to keep revs at 800.

Noticed last couple of days when I have been trying to replicate the problem that even when warm, with nowt electrical on, the rev needle wasn't steady at idle. Although it averaged 800 when stationary, it was fluctuating just above and below. But not all the time.

so, what is on the way out? Would loose battery connections affect this....i ask as I had a flat the other day, and had it out to charge it up - perhaps I haven't got the connections tight enough?

Sorry - haven't tested on petrol - mainly because he runs better and more smoothly on the lpg.

Em
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[toomanytoys]

A few items to check
Dizzy not loose. no air leaks? dizzy cap and rotor arm all good? vac advance on dizzy good and working?
Air filter clean and dry?
try on petrol and see if idle low.. if it is then 1/4 turn clockwise on the idle ajuster on the carb.. (might still need to do this eve if on petrol is ok to get the lpg side rpm up..
Might be worth a 1/8th turn out on the idle bleed on the vaporiser.. (what vaporiser do you have?)

Is it doing normal mpg? gradual decline or all of a sudden? anything changed/serviced/etc

[ermie571]

Hi Si - thanks for the tips!

mpg fine - just done 300 mile round trip to Brum - ran like a dream, picking up when I needed it to, but generally cruising at 60-65.
nothing changed other than the leads to sort out the running on three issue.
Going to engine re-builders for final service, so will mention to them if I can't sort.
Vapouriser is a silver one!! Gasure installation if that helps.
Will try on petrol tomorrow and report back
will have a wiggle of dizzy and see if owt moves. What interested me was the fact that putting more electrical stuff on made the idle fail - why would the dizzy affect this?
thanks
Em
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[toomanytoys]

putting more electrical items on creates load on the engine.. if the engine cant cope with the load, then something is wrong..

if the dizzy has moved timing will be out and idle will drop and not support the extra load.. as will too weak a mixture as will any other ignition/fuel related issues.... switching on the lights etc will not affect the dizzy...

get them to give it check over.. time it up etc etc...

[kevtherev]

mine idles at 1500 from cold Em
drops to 950 when warmed up.

the alternator will rob power from the engine as Si says.. wipers are heavy amps

[Ian Hulley]

Our DJ (set at 5 degree BTDC) on DG carb & lpg does 2000rpm on full choke, gentle tap takes that to 1500 and when fully off sits at 800 steady.

Ian.

[ermie571]

Wow.....Mine never revs that high.....christ, if it gets to 1200 on cold I am amazed!!

right, this morning turned key, 1100 idle and steady, no electrical, not even radio.
Down road, idle ok. Watching it like a hawk...fine and more fine....grrrr. got to lights at top of hill....and nearly lost it, revs dropped. Blipped throttle (it will recover with a quick blip from 200 revs and battery light flashing), then fine. Got to dual carriageway, went to petrol. Switch over fine, power present. got to roundabout, the idle on petrol is high at 1100 revs, so need to get that checked out at the service next week. Will hold the idle on petrol, but still small fluctuations on the needle. Put the lights on, and again the revs dropped, but nowhere near as much, and the engine supported it just fine. Stab in the dark here - but as the idle is lower on gas, when I put the lights etc on, the idle just can't support the load.

Glad its going for service - at least I know there is nothing seriously wrong. Have got a new set of plugs for them to change too. They do the works on the timing, on the gas analyser and timing gun.

Thanks for the tips

Em
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[toomanytoys]

Stab in the dark here - but as the idle is lower on gas, when I put the lights etc on, the idle just can't support the load.



Em
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Thats what I said Em...

ANd as I also said, sounds like the LPG is running weak.. maybe 1/8th turn out on the "power valve" will help..

[ermie571]

Thanks folks, and by the way, I was wrong about my idle from cold - it is up around 1500 when I fire it up! But doesn't stay there very long, which is why I hadn't noticed it

Will get the mixture checked. Si, sorry I just wanted to make it absolutely clear that it was a mixture fault and not an alternator or other ancillary/engine fault.


Cheers all,

Happy Motoring

Em
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