not idling

[81 rangie]

My efi engine doesn't idle at all, it just dies, on petrol but other than that it runs fine. On gas i have no trouble with idling. Does anyone have any ideas to fix my problem
Thanks

[up2nogood]

Air flow meter, they're shits of things.

Or a number of other bits, but these are common.

The LPG is a completely different system, the only bit they share is ignition, so you know that ain't the problem.

[Philip A]

There are so many areas that it could be, caused by not using the petrol enough or a poor gas installation, or a fault with the gas installation
Injection is by itself very reliable.
I sold my old injectors to a guy in Melbourne, who found every one of his injectors seized from dry running. Maybe a relay in the gas system had stuck.
One gas backfire is enough to destroy a flapper air flow meter.

If it only will not idle but runs well otherwise, iI would first clean around the throttle butterfly and the oil vent input with carby cleaner. If it is a 3.9 I would then clean the stepper Motor,(IACV valve).
Regards Philip A

[81 rangie]

might try that Philip, but first i need to know what an oil vent input and a stepper motor is. The car doesn't have a standard AFM, custom made little tube with a plug in it. Also since putting it on gas it has never backfired

[RaginRover]

unplug you afm and see if it runs differently - what AFM do you have? do you have a Lucas 3AM or 5AM hotwire (written on the top of it) or a big old lucas flapper like out of a BMW/Rangie etc ?

In the flappers the flap gets stuck forward and needs pushing back into place (gently) that is usuallly why the stop running on petrol in a dual fuel setup.

I will try and find a pic of a plenium chamber so we can point out what is what

Tom

[Philip A]

It sounds like a 3.9 with a MAF.
The oil vent is the pipe that runs from the RH rocker (from the oil separator) to near the throttle on the casting that sticks out the LH side of the plenum chamber. It enters the throttle body just after the throttle blade .

The stepper is an air valve on the RH rear of the Plenum. It has a number of wires sticking out of it. disconnect the plug and unscrew the "bolt" which is the stepper. It will have a conical end on it with a spring behind it. Clean this with carby cleaner but do not push or pull the conical end. Clean inside the housing it screws into also.
Does your gas enter upstream of downstream of the MAF.
If upstream, the pitch/oil in the gas may have fouled the MAF. Spray" No residue contact cleaner" into the small hole in the MAF, and let it dry out fully before restart.
Regards Philip A

[81 rangie]

I have been told it's a vitesse AFM, as they stroked it to a 4.2