starting/running problem when hot HELP!

[Yon Cun]

I converted my V8 3.9 EFI Discovery 1 last year. The car has preformed beautifuly up untill two months ago. Since then I have changed coil leads plugs distributor sensors to no avail. My problem manifests it's self when car is run up to tempreture. At this point her reves rais on gas as well as petrol. Though the petrol runs very sick and somtimes will not rev from idle and when stopped she will not start for 30 mins. I have cleaned stepper motor, changed air filter and checked all the usual suspects that I know of and been told. I took it back to the gas fitter and he could not help. I know it's not down to gas alown. I need a mechanical guru!
Can anyone help me? Thanks!

[tommo2009]

could be a dead vapouriser adding gas through a split in the diaphram. disconnect the pipe from the vap to the inlet, clamp it off and see if it runs better on petrol.
If it is a mulitpoint system it could be feeding gas back through the vacuum connection. disconnect the vacuum pipe and start the car, see if gas is being pushed out of the vac pipe form the vap.

make sure to block off any open pipes and orifices before trying the vehicle.

[rossko]

Coolant temp sensor (not the gas one, the EFI one) are a common failure

[Yon Cun]

Thanks man the water temp sensore was the problem. Good job I had one! My goodness it has cost me a fortune! But at least now she is better than ever!

[Yon Cun]

Thanks for the help lads!
Getting gas fited to my V8 is the best thing I have done! The system is single point. I have had the odd backfire but they were on cold mornings and around leads and sparkplug changes. Which I do every six month! The gas is 74p ltr at my local garage. Which helps to keep her affordable!
Again thanks Lads!