Intermittent running lean on idle
Discussion
I'm having problems finding a fault.
Every now and then mainly at idle I get a fault it is usually low fuel pressure and one or both lambda I have also had but only once right bank fuel injectors.
I've had a wide band on the car today to monitor the AFR idle usually sits at around 14.7:1 but will sometimes go rich down to about 13.2:1 the lambda on Rovergauge on both banks is now reading -100% this does not bring on any fault codes and with a blip of the pedal it usually sorts it's self out. The faults are coming up when the idle suddenly starts to go really lean about 18:1 and higher Rovergauge is now reading +100% the car then runs terrible on idle drives but very rough the EML light is illuminated and stays that way until the ecu is unplugged and plugged back in. When I restart its ok again I have tried a different ECU but that's made no difference. I have checked all the earths and positives on the lambda heater and they seem fine. All the live data on Rovergauge reads as you would expect. The fuel pump and filter are new the regulator is reasonably new . This is happening just about every time I take the car out. Any ideas or help would be greatly received.
Car is running the Bosch MAF if that makes any difference and has SC power supercharger Mark Adams chip.
Chris
Every now and then mainly at idle I get a fault it is usually low fuel pressure and one or both lambda I have also had but only once right bank fuel injectors.
I've had a wide band on the car today to monitor the AFR idle usually sits at around 14.7:1 but will sometimes go rich down to about 13.2:1 the lambda on Rovergauge on both banks is now reading -100% this does not bring on any fault codes and with a blip of the pedal it usually sorts it's self out. The faults are coming up when the idle suddenly starts to go really lean about 18:1 and higher Rovergauge is now reading +100% the car then runs terrible on idle drives but very rough the EML light is illuminated and stays that way until the ecu is unplugged and plugged back in. When I restart its ok again I have tried a different ECU but that's made no difference. I have checked all the earths and positives on the lambda heater and they seem fine. All the live data on Rovergauge reads as you would expect. The fuel pump and filter are new the regulator is reasonably new . This is happening just about every time I take the car out. Any ideas or help would be greatly received.
Car is running the Bosch MAF if that makes any difference and has SC power supercharger Mark Adams chip.
Chris
chris52 said:
I'm having problems finding a fault.
Every now and then mainly at idle I get a fault it is usually low fuel pressure and one or both lambda I have also had but only once right bank fuel injectors.
I've had a wide band on the car today to monitor the AFR idle usually sits at around 14.7:1 but will sometimes go rich down to about 13.2:1 the lambda on Rovergauge on both banks is now reading -100% this does not bring on any fault codes and with a blip of the pedal it usually sorts it's self out. The faults are coming up when the idle suddenly starts to go really lean about 18:1 and higher Rovergauge is now reading +100% the car then runs terrible on idle drives but very rough the EML light is illuminated and stays that way until the ecu is unplugged and plugged back in. When I restart its ok again I have tried a different ECU but that's made no difference. I have checked all the earths and positives on the lambda heater and they seem fine. All the live data on Rovergauge reads as you would expect. The fuel pump and filter are new the regulator is reasonably new . This is happening just about every time I take the car out. Any ideas or help would be greatly received.
Car is running the Bosch MAF if that makes any difference and has SC power supercharger Mark Adams chip.
Chris
are you still running a stepper motor?Every now and then mainly at idle I get a fault it is usually low fuel pressure and one or both lambda I have also had but only once right bank fuel injectors.
I've had a wide band on the car today to monitor the AFR idle usually sits at around 14.7:1 but will sometimes go rich down to about 13.2:1 the lambda on Rovergauge on both banks is now reading -100% this does not bring on any fault codes and with a blip of the pedal it usually sorts it's self out. The faults are coming up when the idle suddenly starts to go really lean about 18:1 and higher Rovergauge is now reading +100% the car then runs terrible on idle drives but very rough the EML light is illuminated and stays that way until the ecu is unplugged and plugged back in. When I restart its ok again I have tried a different ECU but that's made no difference. I have checked all the earths and positives on the lambda heater and they seem fine. All the live data on Rovergauge reads as you would expect. The fuel pump and filter are new the regulator is reasonably new . This is happening just about every time I take the car out. Any ideas or help would be greatly received.
Car is running the Bosch MAF if that makes any difference and has SC power supercharger Mark Adams chip.
Chris
Yes still running a stepper motor but that seems to be functioning fine and when it goes lean even if you put your foot on the loud pedal it's still running extremely lean and very poorly won't rev much and no power. I am going to check the fuel pressure and Bosch MAF sensor today to see either of those are going wonky.
Chris
Chris
Ruled out fuel pressure that stays ok. With RG plugged in and a wideband sensor the car keeps a steady 14.7:1 on idle give or take while the Lambda readings on RG are occilating. One lambda readings will then go static could be either left or right followed shortly by the other and then the AFR starts to go wherever it wants and eventually goes super lean and brings on the fault codes. While the Lambdas are static if I blip the throttle pedal they start occilating again and ARF goes back to normal for a while until the lambda readings on RG go static again. Any ideas?
chris52 said:
Ruled out fuel pressure that stays ok. With RG plugged in and a wideband sensor the car keeps a steady 14.7:1 on idle give or take while the Lambda readings on RG are occilating. One lambda readings will then go static could be either left or right followed shortly by the other and then the AFR starts to go wherever it wants and eventually goes super lean and brings on the fault codes. While the Lambdas are static if I blip the throttle pedal they start occilating again and ARF goes back to normal for a while until the lambda readings on RG go static again. Any ideas?
Have you checked the injectors? If one is faulty or not getting a good signal it will try and compensate causing oscillation your seeing.worth a look?
Think it's sorted at least it hasn't done anything wrong in the last few tests plus the Lambdas now carry on sweeping back and forth and don't seem to go static. The fault was that the stepper motor wires which are extended due to the plenum being on the opasite way round on the supercharged cars were touching the HT leads which must have been sending a strange signal to the ECU and it it determined that the faults were fuel pressure or lambda.
Fingers crossed
Chris
Fingers crossed
Chris
Fingers crossed I may have found the problem. The wiring to the pump must have deteriorated and as a result I was only getting 10v to the pump and probably a lot less when the car started pinking. Just adding a new feed you could hear the pump speed up dramatically.
Worth checking your wiring guys
Many thanks for all the help
Chris
Worth checking your wiring guys
Many thanks for all the help
Chris
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