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Hi All

Having fitted a replacement cylinder head to get rid of poor running due to loss of compression, I was somewhat miffed to find that the car still stalls until fully hot. I thought this fault was connected to the loss of compression too, but oh no.

The car starts OK from cold, but cranks over more than I think it should before firing. It then drives OK for about half a mile. At that point you can feel it cut out at low revs only to pick up again when applying some throttle. If you have you stop at a junction - and I do whichever route I take, it's a major problem. It will idle, but as soon as it's given any gas it stalls. The only way to make progress is to put your left foot on the brake, rev it hard and bosh it into drive with the associated lurching or stalling.

Once it's fully warmed up, it's absolutely fine so I would suspect a dodgy temperature sender - but...the previous owner fitted a new one plus a new crank position sensor and a second hand MAF.

Any ideas?

Cheers

Glen.

Glen,

I'd still be looking at the temp input to the ecu first. Remember that you have a temperature sensor and a temperature transmitter which sit together. Perhaps the PO only changed the one which is providing the gauge signal not the input to the ecu?

Cheers

Paul

I`ve experienced similar issues on 4.0 litre and 4.2 litre later V8 models with duff temperature sensors. Cold starts were badly affected. Paul`s comments are very relevant.

These sensors need to be of correct OE value. Recently, as I could not get an OE part at short notice over the Christmas period, in desperation I fitted an after market part said to be correct for the car. That`s another story in itself! Fit only genuine Jaguar OE sensors to our cars. Fit wrong value and the controlling ecu can have a head fit!!! The PO may well have fitted incorrect parts.

Mike K

Thanks for the advice guys.

The PO did change the correct sensor, but yesterday I swapped it out for the one off my spare head and the car was fine this morning.

Someone has suggested it might be a throttle position sensor fault which kind of makes sense. Maybe it gets dodgy if it's not run for a few days? I will give it all a good dose of carb cleaner anyway.

Cheers

Glen.