Thread: Fuel Rail 3.9V8

Do the water pipes run under the manifold now? If so, it's off an '86 or '87 model RR.

I'm guessing that the sensor would be fuel temp for the hotwire injection system. I think the ECU would take a mid-range setting by default but I can't say what effect that will have on your engine.

The pipes don't go through under like on the earlier ones. On the original, the pipe into the manifold wentin the front, below the thermo housing, on the new one, it goes in on the side, on the other side of the thermo housing. I guess there should be pipes running down the side, like mine had. I'm not running my heater so it plumbs up real easy.

I'm guessing it's fuel pressure. Is this senser important for the running of the car? The car is running but is a bit rough but there are a couple of ther things that need sorting as well so may not be the senser. Any ideas if I need this or not?

The sensor is fuel temperature and tells the ECU to take into account the different density of hot fuel ( less dense) so it richens up a bit. I guess it depends on how hot the fiuel gets but I would think that the sensor would help hot start, and I think that is its' primary purpose.

If you have a 3.9 it must have had one somewhere. Some discos have this sensor about half way down the LH of the fuel rail.
Regards Philip A

Post a pic of the old and new. Is easy to ID visually.

Cheers

Andrew.

Originally Posted by PhilipA

The sensor is fuel temperature and tells the ECU to take into account the different density of hot fuel ( less dense) so it richens up a bit. I guess it depends on how hot the fiuel gets but I would think that the sensor would help hot start, and I think that is its' primary purpose.

If you have a 3.9 it must have had one somewhere. Some discos have this sensor about half way down the LH of the fuel rail.
Regards Philip A

I've just remembered that there is a sensor on the LH side, half-way down. Must be a disco manifold. i'll extend the wires and plug it into there.
Thanks for your help guys!