Hi I've had my rr p38 2.5 diesel on the diagnosis last night and the temperature read out for the engine is -35 and the fuel temperature is also reading -35 the engine temperature on the dash does not work either. Which of the sensors need changing. There are two near the front of the head under the inlet but what is the one near to the back as there is no wiring to it and I can't see any wiring plugs hanging around.
temp sensor which one?
- Thread starter paulcl09
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
- Posts
- 58,170
- Location
- Preston Lancs.
What year is your car does it have aircon?
It has air con and I think it's a 1997 not 100% sure only had it a week. It's an R reg
- Posts
- 58,170
- Location
- Preston Lancs.
Does it have EGR? (Black plastic inlet manifold). With turbo hose going to the metal EGR valve in front of manifold.
- Posts
- 58,170
- Location
- Preston Lancs.
Ok doesn't matter about year.
http://www.rimmerbros.co.uk/Item--i-NSC100820 Blue sensor, dash gauge sensor with aircon two pin, first one on head above injection pump.
http://www.rimmerbros.co.uk/Item--i-STC2299 Green sensor, second one on head ECU temp sensor.
http://www.rimmerbros.co.uk/Item--i-STC2254 Black sensor only fitted after 1999 to bring aircon fans on with overheat. Not required on you car the loom will not support it. Maybe it has had a later head fitted.
http://www.rimmerbros.co.uk/Item--i-NSC100820 Blue sensor, dash gauge sensor with aircon two pin, first one on head above injection pump.
http://www.rimmerbros.co.uk/Item--i-STC2299 Green sensor, second one on head ECU temp sensor.
http://www.rimmerbros.co.uk/Item--i-STC2254 Black sensor only fitted after 1999 to bring aircon fans on with overheat. Not required on you car the loom will not support it. Maybe it has had a later head fitted.
Ok thanks again. It has a metal inlet no egr but it had the metal pipe from the exhaust to the egr but it's been blanked off.
- Posts
- 58,170
- Location
- Preston Lancs.
Must be MY1998 then if it has the metal EGR pipe across front of engine. EGR came in 1998 and has had an earlier head fitted. Maybe they fitted the black sensor just to fill a hole. If it's an early head it may have the wrong gauge sensor fitted. It may have the single pin Brown one fitted. With aircon it needs to be the Blue two pin sensor. Make sure first sensor is Blue and second one is Green for a start. You will have to do a search for the blue sensor if you need one. Is there a MAF sensor fitted just after air filter box?
Hi no maf sensor vas far as I know I'll check later. There is a blue sensor but it's the second one along and it looks new. I'll get some pics tonight so you can see.
Cheers
- Posts
- 58,170
- Location
- Preston Lancs.
It's in the wrong place then Blue should be first sensor second one should be Green. They are different and cannot be interchanged no wonder your readings are tits up. Bit of a mongrel then, looks like someone has been doing a bit of mix and match. Have a look for a inlet air temp sensor under front of manifold with a loom plug on it if it has that it is definitely pre EGR.
Ok so do the electrical plugs on the temperature sensors both fit each other can they mixed up and plugged on the wrong sensor? As I guess both the sensors are screwed in to a water way. Yes it has the air temperature sensor in the bottom of the inlet manifold. It was registered September97. Yeah it's been well and truly bodged it was very cheap just trying to save it from the scrap man. Also is there any way of testing the injector with the wire on it as it has an injector begin fault? Could this cause it to be very under powered? I got some boost pipes today as mine have started to collapse inside.
Cheers
- Posts
- 58,170
- Location
- Preston Lancs.
What diag did you use? That fault would indicate number four injector may not be working properly. But it could be other things. Check connections to plug and wiring first of all, number four injector signals ECU injection point. Then ECU from info from CPS modulates timing solenoid to adjust injection timing. If that is not functioning properly you will get a lack of power. But if number four injector is totally duff MIL lamp should be on. Fit your bits and see what you get. Look at pipe from under manifold to MAP sensor bolted to top of fuel filter. Make sure it is sound with no cracks or leaks and that where it fits to manifold is clear. You can clean MAP sensor air inlet with a little contact cleaner and a gentle blow with an air line don't poke anything sharp into it. Cleaning out the intercooler maybe a good move also. Paraffin swished about in it several times will do the job. Make sure it is well drained before refitting. The loom plugs should not reach to swap over incorrectly placed sensors you will have to remove them and fit them correctly. Easy to do with manifold removed. First one MUST be Blue second one MUST be Green.
- Posts
- 18,999
- Location
- Buckinghamshire, UK. ('95 DT)
Pictures!
Ok just been out with rr now the sensors are in the correct place blue one nearest the front of engine. Now the blue one is a 2pin but the plug only has one wire is this correct. I tried the boost hose and replaced the pipe on the map sensor but there is still no power I'll pop some pics up.
Cheers
Attachments
Ok so I justr read somewhere that engine speed signal is needed for the injector with the wire. I noticed my scanner was reading 92rpm and didn't change if I revved the engine? But if it didn't know the engine speed surely it wouldn't start.
Would someone be kind enough to get me a wiring diagram for the engine sensors to the ecu. I tried downloading rave but can't get it to work.
Thanks
Would someone be kind enough to get me a wiring diagram for the engine sensors to the ecu. I tried downloading rave but can't get it to work.
Thanks
- Posts
- 58,170
- Location
- Preston Lancs.
OK start again just looked again. Blue sensor is only after 1997 that is 1998 and on. So the single wire on your plug is correct. Sorry about that. You need this sensor. http://www.rimmerbros.co.uk/Item--i-STC2253P Microcat parts list is misleading with this part. It states Blue sensor with aircon. But RAVE says Brown sensor MY 1997, Blue sensor MY 1998 and on. So you need a Brown sensor for the where the Blue one is and the other one still needs to be Green.
- Posts
- 58,170
- Location
- Preston Lancs.
No engine speed signal is not needed for the number four injector read what i posted earlier. It sends the actual start of injection info to the ECU the ECU then compares signals from the engine speed sensor to the start of injection from number four injector then modulates the timing solenoid to adjust injection timing. Can your diag read modulation if it can it should be between 45% and 55% engine normal temp at idle. If it's a higher than that static timing is retarded, if it's lower than that static timing is advanced. You need some proper diag on it like Nanocom not a lot else with play with the diesels properly.
- Posts
- 58,170
- Location
- Preston Lancs.
And by the way that engine has had plastic manifold on it at some point. So the engine is newer than the car. 
Hi I don't think it reads modulation could there another term used for it? Is the wiring connector correct for my blue temp sensor it only has one wire but two pins in the sensor. Also it seems abit strange how everything in that area doesn't work both sensors and that injector? I found loads of gunk in the Mao senator pipe so I replaced it cleaned out the sensor but still no power. Also the fuel temp sensor doesn't work?
- Posts
- 58,170
- Location
- Preston Lancs.
As i said you will need a Brown sensor for your year of car. Brown sensor grounds through engine. Blue sensor has a ground on pin 2 so will not work on the single wire loom in your car. Think you had better get some proper diag on it to be honest then you will know what you are up against. What diag are you using? Did you mean MAP sensor? Maybe timing percentage or something like that.
