Fuel, Water Temp Sensors (replacement needed)

[dalecrx]

Hi

I have a 4.0 HC and it does not idle smoothly, I have done the usual things and now im planning on changing the fuel and water temp sensors as I think it might be down to these too. I read in the bible that by replacing these, it can make a big difference and someone on the board mentioned it too, as he was having the same problem.

Are these sensors standard, as if they are I would prefer to buy them from a parts place instead of a TVR garage.

Anybody ever replaced these 2 sensors before or knows if they need to be bought from tvr??

Thanks in advance

Dale

[k4trv]

What "fuel" sensor does the bible refer to? The "fuel" is provived by a high pressure pump, relay controlled. The only sensor I know is a pressure sensor, which when tripped (45 to 50 psi, it does vary with plenum vacuum), feeds fuel back to the tank.

To be honest I haven't seen anyone refer to this before as a reason for rough idle?? It would certainly influence pick-up and full-throttle performance.

Temp and stepper motor maybe ?? But even the temp sensor would in my opinion be a last-item-to-check for a "rough tickover".

I'd be more inclined to check air cleaner, throttle sensor, intake condition, ignition, timing, plugs, injectors (use a fuel inj cleaner), before going anywhere near temp sensor and "so-called fuel sensor" ???

Maybe you've tried all of these???? Just trying to be helpful !!

Trev McM

[greenv8s]

There is a fuel temp sensor in the front of the fuel rail.

[dalecrx]

If you look it up in the manual, it does mention the fuel temp sensor and if its out of calibration it can lead to overfuelling when the engine is cold and idling causing too much fuel which can lead to lumpy running below 2000rpm. I read a similar post by someone else on here when i was doing a search.

Dale

[shpub]

Might be worth checking that they are accurate with a multimeter first before replacing them as they are not cheap. About £15 each. Details in the bible on how to do it.

[dalecrx]

This is the link where someone similar had the rough idle and kangaroo-ing down the road.

www.pistonheads.com/gassing/topic.asp?t=10846&f=8&h=0&hw=rough+idle