over the last week the sapph started running a little rough,idle wasnt as smooth and occasionaly on boost it would splutter.

the car is stg3 runninga msd closed loop chip.whilst trying to sort the problem out i was messing with the lambda sensor and once i unplugged one of the pins(black one) it drives alot better,the senosors only a few months old could it be shot?why would it work better with it unplugged??

any help appreciated.

 

i have no idea why, Karl at NMS explained to me once, but i cant remember, I run mine without lamda too

 

If it is set up to run closed loop it should run worse with it disconnected I would have thought at idle anyway.
The black is signal wire, ie info going back to ecu about co mix, the one important wire!!
They can be buggered by too much oil if it is burning a lot ?
tabetha

 

WRONG!

The ECU will revert to pre-set parameters in the software (chip) in order to acheive something near Stoich (Lambda 1) at the times that closed loop is required (Idle, less than 33% throtle (iirc) and below something like 2400rpm also when cruising at a constant speed with the engine load pre-determined by the MAP sensor) in order to acheive the best economy and driveability with a failed lambda sensor.

 

it runs better with the balck wire unplugged tabs as graceland has said.

it is meant to be running closed loop,took it to a place local to me and he said the problems lying within the the chip,once the lambda is plugged in the mixture gos mental and runs lumpy as hell..is it a case of it needing a full set up or....?

 

If it is a problem with the chip, I'd be inclined to get in touch with Stu - remember, his remapping products carry a lifetime warranty and his technical support is A1.

Alternativly, try a known good lambda sensor, my money is on the sensor being out of tolerance

 

yeah was thinking to get intouch,eventho he didnt put it in for me,one of his suplliers local to me did..

 

oh if the sensor is out of tolerance is it an easy fix?

 

If the sensor has gone out of tolerence then it is simply a case of putting a new one in there - 10 min job at the most providing the sensor isn't seized in the turbo housing

 

id defo say sensor is fucked , this happened on my fiesta rs1800 started misfiring at 2300/2500 rpm , run like a bag of shit , and that was running a brand new bosch unverisal 4 wire sensor took me ages to find out what it was i as i thought the bosch sensor would be last thing wrong . it had only been on the car 6 months before it started to play up and then the car started to cut out , thats when i unplugged it and like you said it drove grate so i went to the scrappys and got 4 ford sensors for Ł1 , banged one in and run fine ever since
cheers paul

 

thanks chaps..stupid senor is only a couple of months old

 

Not uncommon for them to fail unfortunately, hence why places like Fuckfit fit loads of cat convertors - they don't tell the owner the cause of the problem, only treat the symptom instead of performing a diagnosis and replacing the cause.

 

What have the local suppliers said about it?

 

need to take it down to him to have a look at it mate