Club 80-90 Forums

2.1 carb running LPG and petrol

Idle fluctuating. Some days fine. Somedays revving its little wotsits off!!

Got to work car park today......idle high on LPG. Switched to petrol, idle fluctuated....came back high. Back to gas....small fluctuations, then high.

Not fiddled/touched/turned owt in the engine bay.

Have got a rev counter in cab....all mounted but not wired in yet, but that is a seperate issue.

Thinking that it may be
a vacuum hose? (does the 2.1 have them?)
Sucking air from somewhere else (any prime contenders)
Sommat to do with my dizzy being 180 degrees out
Sommat else entirely!

running fine.
pulling very well

thanks for advice

Em

Just started doing it?

sounds like fast idle cam of carb maybe sticking.. or throttle cable not returning fully.. if you "blip" the throttle, will it settle?
if there was an air leak then on lpg would generally run slower.. (less vac= less gas..)

Dizzy advance mech sticking?

Hi Simon,
thanks for the reply.

No - been doing it a little while.

Blipping the throttle doesn't help. Don't think it is an issue with the throttle cable - I should have mentioned it doesn't do it from cold....the engine needs to be warm before it plays up. But had a long run last weekend....didn't notice it much then. Temp stayed nicely in first third of the normal range (about 5 to on the clock I suppose)

then the shorter run to work as soon as the needle came out of the cold section, the idle picked up?

idle cam of carb....do I spray carb with wd40????
Dizzy advance.....how do I check???

thanks again
Emma

edited to add.....think I will have to keep a record of what it is doing and when!! Intermittent faults are the worst devils to sort!

ok.. wd on the springs etc..

Dizzy, pop the cap off and see if the rotor arm can move freely and easily backwards and forwards a few degrees..
If you have a timing light, you could check the timing moves smoothly while running.. disconnect the vac and from idle increase the rpm so you can see the timing mark move...

Many thanks Si

Gives me somewhere to start!