I have a Discovery 1 V8 and TVR Chimaera both with similar problems. The Discovery has only just started with it in the last few days, but now is the worst of the two, especially on LPG.

With the TVR I start it, let it warm up, idle is a little erratic, reverse out of drive and when I stop to select 1st the engine dies and won't start. It usually take 2-3 tries and a couple of minutes wait until it will start. Sometimes the next junction it stalls again. After then its fine and idles fine.

Little different with the Discovery as its parked on the road. I start the car fine, let it warm up a little, idle is a little erratic, drive down the road and at the first junction the engine stalls. It then takes 2-3 tries to start it, but today it took about 5, only starting with the throttle fully open (flooded I think). It drove fine for 5 miles, idling great, until I stopped in town to let oncoming traffic pass parked cars, then it stalled and refused to start. I must have tried 10 times at least to start it. Decided it may be a job for the AA and as I was 2ft from the kerb selected reverse and used the starter to drive me back into a parking space, during which the engine decided to start. Form then on it idled fine and didn't do it again.

I've a feeling its the same problem with both cars. The TVR has had new plugs, leads, dizzy, stepper motor cleaned and confirmed working and a service. I've not tried anything with the Discovery yet.

Any Ideas?

could be a fuel quality/contamination problem

I notice you live in the middle of nowhere - speak to someone else locally who drives a petrol car and see if they have been having problems

Ignoring the LPG on th eDisco I would have said you might have a couple of issues there. First I would remove and clean the plenum and ram housing and then check and set the throttle disc.

Next I think I would want to be checking the throttle potentiometer, check base voltage and then check scaling.

The other possibility with stalling coming off the throttle is a vacuum leak that causes the mixture to go extra lean when throttle closes and the ECU can't react quickly enough to keep it alive. Check the vac advance unit and connecting hose. Check your ignition timing, if it is retarded you might have stalling type problems but find oust where the timing needs to be for LPG.

Lastly, you might want to have a look at the flame trap and engine breather and make sure both are clean and clear as well as any associated pipework.

You say the disco is misbehaving on LPG - can't hep with that but I would be reasonably sure that will not use the fuel injection ECU so the issue could be an air leak, incorrectly set throttle disc or simply that the LPG system needs a service.

I think the problem is same with LPG or petrol, just it runs better on petrol. Petrol in all my cars are from same station and my pick-up, bike and lawnmower run fine.

Thanks for the advice Kev. I always think of electrical problems when its not running fine, now I've something else to look at.

One thing I noticed this morning, giving it a rev approaching the junction when I'm dropping it into 2nd stopped it stalling.

Heres an extract from the net that may help,

The reason for stalling with a defective (or absent) Road Speed Sensor is quite simple. Under normal operation when slowing down for a halt, the throttle may be closed but the engine is being driven by the inertia of the vehicle whilst the car is in gear (overrun). Because of the Road Speed Sensor the ECU will not try to adjust the idle in these circumstances, so the idle control valve is held open until the vehicle halts. The effect of this is that when the vehicle does halt, the idle valve is open and the ECU drops the engine onto idle smoothly.


Its taken from here Lucas 14CUX Fuel Injection System ? Installation and Diagnostic Notes.

Might help a bit,
Steve