cant locate tune resistor any help please

hi all. i posted a couple of wks ago a picture of the tune resistor i thought i found but now turns out to be part of the lpg system as i did have a member also say that was it as it was red. also i have brought a ecu mate diagnostic which says i have a white tune resistor fitted. so the problem is were is it as i have been looking just left to the bottom of the steering colume were the loom comes across. but some say its by the ecu back of the glove box passengerside. my motor is a 1995 3.9v8 disco 1. can some please put me in right direction as its doing my head in now.

I have the same as you in the picture you posted before and mines a diesel.

hi russ that thing i thought was a tune resistor is not it goes onto a relay 1 single wire from it.so i assumed it can only be to do with the lpg. but it defo is not the tune resistor because it suppose to be in a clear piece of plastic. and i dont think diesels have them but might be wrong.

I have no idea what it is. Just found it whilst poking around to try and sort my abs problems, and noticed it and thought about the pictures you put on.

I don't see much of old v8's like this now.But what I can tell you is that the tune resistor on 14CUX injected v8's is always in the loom around 10-12" from the main ecu plug. I simply cant remember which direction the loom goes from the ecu,but its always 10-12"away from the ecu.

yes will look tomorrow. russ what the tune resistor does is if you got cats then for uk its white and it does something with ecu and adjust fuel. if you got no cats you have to fit a green one so the ecu gets no signal from the lamba sensors. i just want to do away with my lamba sensors as im modifying the exhaust system with 3" diameter all through then just fitting a cheery bomb sort of silencer at rear.so because i will have no cats i need to fit a green resistor so the ecu dont get signal for lambas its along this line.

The ecu is on drivers side kick panel wall on mine, pretty sure 3.9s are the same

Anyway pull the big ecu plug and access around a foot of loom as stated, unwrap and it will be there, on a little bit of extra wire so it is accessible

You are correct, fit green, ditch cats, get full range fueling back, be happy!

Expect fuel consumption to go up because you will spend more time running at less than stoich, but she'll run better and make good power.

If you are doing away with the cats you would be just as well leaving the oxygen sensors in place.The ecu will ignore them under heavy load/wide throttle openings anyway - so you wont get any more power by getting rid of them,all you will do is waste fuel.They are also useful to diagnose running issues.
And don't believe all the crap about lean running causing cracked blocks etc - its just crap. Your LPG if its badly setup is much more likely to harm the engine.

I was under the impression it was the high temp thermostat in the p38 that was the main reason for making them run hot.

You have a point about leaving the lambdas in but also the ecu will try to lean out past 14.7 on green tune whereas on lambda tune it tries to maintain 14.7

As far as i know green is generally a better option, simpler too, BUT maybe OP could conduct his own experiments for performance and mpg etc?

Mr Noisy said:

I was under the impression it was the high temp thermostat in the p38 that was the main reason for making them run hot.

You have a point about leaving the lambdas in but also the ecu will try to lean out past 14.7 on green tune whereas on lambda tune it tries to maintain 14.7

As far as i know green is generally a better option, simpler too, BUT maybe OP could conduct his own experiments for performance and mpg etc?

Click to expand...

Without oxy sensors the 14CUX open loop fuel map is a blunt instrument,far better with closed loop control.
Nobody mentioned P38's - back in the day various v8 "Experts" blamed weak mixtures from closed loop control for cracked block/loose liners on 94mm bore Rover v8's. It was all crap - as were/are the engines.If they insisted on building them so badly they should have fitted top hat liners from the start.Or just built an engine with wider bore centres and more material behind the liners to start with.....