Thread: Running rough on petrol

Originally Posted by Hall

As the title states which is a understatement. Not sure what to look at, so many options. Runs ok on gas with one issue that also relates to the petrol problems. Does idle a bit slow. On petrol this low idle is also combined with a rough idle or it could be miss firing ? or it could be crappy fuel? When I go to launch away it gags and stutters then get it`s self sorted and we move off. When I am running on petrol at speed, say about 95- 100 km it also is running a bit rough, like it is missing. This makes me think it might be fuel related as it doe not do this on gas. Did replace the fuel filter some twelve months ago. Not sure what the interval is for changing them. Spark plugs are the ones that cam with the Disco, so could be any age. So might just replace them regardless. Hopefully it is not injectors, but knowing how things go with me that will be the culprit.
Cheers Hall

How old are the plug leads? Might be worth changing to new ones? Sometimes they can have cracks in them and the spark arcs on to the metal.
How's the fuel pump? Noisy?

Originally Posted by SPROVER

How old are the plug leads? Might be worth changing to new ones? Sometimes they can have cracks in them and the spark arcs on to the metal.
How's the fuel pump? Noisy?

No good replacing plug leads if it runs OK on LPG, gas is harder on ignition components than petrol. I'd be targeting gone off petrol, a dud MAF, dud EFI temp sender, dud fuel pump and dud injectors in that order. You need to know how to test these things, blind replacement of everything will cost more than the vehicle is worth. You'll need to start with a test light, a multi meter and a workshop manual. Or just drive it on gas until it finally blows up.

Originally Posted by bee utey

No good replacing plug leads if it runs OK on LPG, gas is harder on ignition components than petrol. I'd be targeting gone off petrol, a dud MAF, dud EFI temp sender, dud fuel pump and dud injectors in that order. You need to know how to test these things, blind replacement of everything will cost more than the vehicle is worth. You'll need to start with a test light, a multi meter and a workshop manual. Or just drive it on gas until it finally blows up.

Yep fair enough. But he does say there is misfiring on both fuels.

Originally Posted by SPROVER

Yep fair enough. But he does say there is misfiring on both fuels.

I didn't see anything in the OP about misfiring on gas but slow idle was mentioned. That is either a stuck idle stepper motor or the base idle screw needs a couple of turns outwards.