ovalandrover

ovalandrover

Well-Known Member
today i fitted a new ambient air temperature sensor and it cured one fault but caused another
the new fault is the idle is around 1100 rpm instead of 750but if I put my foot on the brake and just open the throttle a little it drops to 750 take foot off brake and back to 1100.
take the sensor out and idle is 750 again has had faults read by nanacom and autologic and no faults found.
anyone any ideas?
 
ovalandrover said:
today i fitted a new ambient air temperature sensor and it cured one fault but caused another
the new fault is the idle is around 1100 rpm instead of 750but if I put my foot on the brake and just open the throttle a little it drops to 750 take foot off brake and back to 1100.
take the sensor out and idle is 750 again has had faults read by nanacom and autologic and no faults found.
anyone any ideas?
Click to expand...
The ambient air sensor that gives the temperture on the HEVAC display?
It should have no connection to the engine idling other than it affects the aircon operation.
Do you get the correct ambient reading with the new sensor?
Or do you mean the inlet manifold air temperature sensor?
 
Yea ambient sensor is by the front grill I think he meant temp sender was it the guage one or the ecu one? What colour was it ?
 
Grit Valve said:
Can't remember buts its got plastic air intake the egr and the Solinoid attached to the bulk head behind the eas box , for the egr
Click to expand...

Yes i remember seeing that on the photo of the old tuning box you posted.Think the man better come back on a tell us. I have doubts about the old tuning box being fitted to the newer ECU. The one with the MAP pipe is fairly old, maybe mid nineties before EGR, it maybe causing a few problems. I have said this before, not sure but it maybe a good idea to disconnect it and see what he gets then.
 
I may be wrong about this, but if his is the EGR version, where did he plug the pipe that usually goes to a Tee-piece that is connected to the MAP pipe ? IIRC the EGR ones don't have a MAP, right ?
 
The car is a 1999 it has egr and map and maf the ambient air temp was a green one that was hanging under the manifold with no obvious place to plug it into.
the old one was burnt out so i replaced it with a genuine land rover one which is black.
this cured my gearbox fault but gave the above symptons
It almost sounds like the air temp is reading to cold and has the cold start idle engaged all the time but the brake and throttle one is a mystery.
The power box has been fitted to the car since i bought it but when i dissconect the sensor the idle is correct perhapse someone could test the one on their car and let me know what ohm readins they get and at what temperature?
 
ovalandrover said:
The car is a 1999 it has egr and map and maf the ambient air temp was a green one that was hanging under the manifold with no obvious place to plug it into.
the old one was burnt out so i replaced it with a genuine land rover one which is black.
this cured my gearbox fault but gave the above symptons
It almost sounds like the air temp is reading to cold and has the cold start idle engaged all the time but the brake and throttle one is a mystery.
The power box has been fitted to the car since i bought it but when i dissconect the sensor the idle is correct perhapse someone could test the one on their car and let me know what ohm readins they get and at what temperature?
Click to expand...
If it has an EGR and a MAF, it should have a plastic manifold and no IAT in the manifold, temperature of ambiant air is sensed in the MAF.
 
mcapinha said:
I may be wrong about this, but if his is the EGR version, where did he plug the pipe that usually goes to a Tee-piece that is connected to the MAP pipe ? IIRC the EGR ones don't have a MAP, right ?
Click to expand...
They all have a MAP sensor.
 
wammers said:
Yes i remember seeing that on the photo of the old tuning box you posted.Think the man better come back on a tell us. I have doubts about the old tuning box being fitted to the newer ECU. The one with the MAP pipe is fairly old, maybe mid nineties before EGR, it maybe causing a few problems. I have said this before, not sure but it maybe a good idea to disconnect it and see what he gets then.
Click to expand...
+1 wrong Power box.
 
This problem deepens. The green sensor is the ECU temp sensor. There should not be a wire hanging down under the manifold with a sensor attached. The wires for the sensors should come up from the loom feeding the glow plugs. The sensor should be in the head. Think you need to get a mechanic or someone who knows what they are doing to look at your car. If it's a 99 remove the power box it's the wrong one. If the sensor is not in the head the ECU thinks the engine is cold and will run the engine at fast idle. Which is 1100 RPM. With the sensor disconnected or duff a default temp of 50 degrees is used.
 
Last edited:
Yes confusing blue and green are( water) temperature sensors there is also a black one for air con these should be screwed in to the side of the head .
the plastic manifold has two hoses one for the map that goes to the fuel filter and one to the egr vacume Solinoid
The early ally manifold has one pipe going to the map sensor on the fuel filter housing and another air sensor screwed into the ally air manifold this is what the plastic one doesn't have instead it has a ( maf) sensor is everybody clear

Ambient is outside temperature and is displayed in the hevac screen.
 
Grit Valve said:
Yes confusing blue and green are( water) temperature sensors there is also a black one for air con these should be screwed in to the side of the head .
the plastic manifold has two hoses one for the map that goes to the fuel filter and one to the egr vacume Solinoid
The early ally manifold has one pipe going to the map sensor on the fuel filter housing and another air sensor screwed into the ally air manifold this is what the plastic one doesn't have instead it has a ( maf) sensor is everybody clear

Ambient is outside temperature and is displayed in the hevac screen.
Click to expand...

Nothing confusing about it. The lad tries hard but obviously has not got a clue what he is doing.
 
If the sensor should not be there how come when i eyt a new one iy cures my high gearchange fault.
the power box has been on car since i bought it and does not give me any problems.
I nptice that no one has answered my query about the when brake is applied and the throttle just otened about 1/8 in the id;e is correct so the brake switch must be ibcorperated there somewhere.
since I have had this car ive driven it 60000 miles over some of the worse roads imaginable and will do the same again after some repairs and maintinence.
as for the sensor why bis there a coupling from the loom at the back of the engine to fit one? and also it has cured my gearbox high change issue.
 
ovalandrover said:
If the sensor should not be there how come when i eyt a new one iy cures my high gearchange fault.
the power box has been on car since i bought it and does not give me any problems.
I nptice that no one has answered my query about the when brake is applied and the throttle just otened about 1/8 in the id;e is correct so the brake switch must be ibcorperated there somewhere.
since I have had this car ive driven it 60000 miles over some of the worse roads imaginable and will do the same again after some repairs and maintinence.
as for the sensor why bis there a coupling from the loom at the back of the engine to fit one? and also it has cured my gearbox high change issue.
Click to expand...
The power box may have failed, to prove the point disconnect it.
Sounds like you have some confusion over which sensors go where.
Apart from the increased load of the brake lights and brake pump, there is no connection to the idle speed that I'm aware of.
There are a number of spare connectors on some cars, it does not mean they should be connected.
If you are connecting the wrong sensor or the wrong connector, as Wammers said, it will affect the way the engine runs, no sensor and a default value is used.
 
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