AFRs at idle and 2500rpm, no problems?
08-28-2011, 03:50 PM
#16
Racer
Thread Starter
How did you wire in the NB signal into the piggyback? How did you pick up the NB signal?
There are a handful of things that can knock the car out of closed loop.
A bad o2 harness can cause it. Confirm that DME pin 24 has continuity to the harness side O2 plug under the hood when the car is warm. Wiggle the wires when testing to check for bad connections in the harness.
The car will not be in closed loop when the full load signal is triggered by the KLR. To test, run the motor so that it should be in closed loop but is failing to stay at 14.7. When the motor is running like that, check for 5 volts on pin 18 of the KLR. If it instead shows 0 volts, then your "full load" signal is on, which could be either a bad KLR, or the throttle position sensor is giving a bad reading (i.e., it is indicating a wide open throttle when the throttle is only slightly open).
A TPS that falsely shows an open throttle can cause it. To test, KLR Pins 22 and 23 should have 320-670 ohms with the throttle closed and 2.7k-4.7k with the throttle open, when a smooth progression as the throttle opens.
If AFR is too far out of range, the o2 cannot pull it back to 14.7. Might test the temp sensor at the DME (to check both the sensor and the harness). Confirm DME pin 13 has 1.4k-3.6k at ambient temp and 160-210 ohms at 100c.
If you have a spare DME handy, try it.
Confirm that the regional coding plug is not installed, as this could put you into race gase maps which may or may not use the close loop system.
Confirm that you have zero exhaust leaks in front of or near the o2 sensor, as those can (and will) throw off your readings and cause you to chase your tail.
There are a handful of things that can knock the car out of closed loop.
A bad o2 harness can cause it. Confirm that DME pin 24 has continuity to the harness side O2 plug under the hood when the car is warm. Wiggle the wires when testing to check for bad connections in the harness.
The car will not be in closed loop when the full load signal is triggered by the KLR. To test, run the motor so that it should be in closed loop but is failing to stay at 14.7. When the motor is running like that, check for 5 volts on pin 18 of the KLR. If it instead shows 0 volts, then your "full load" signal is on, which could be either a bad KLR, or the throttle position sensor is giving a bad reading (i.e., it is indicating a wide open throttle when the throttle is only slightly open).
A TPS that falsely shows an open throttle can cause it. To test, KLR Pins 22 and 23 should have 320-670 ohms with the throttle closed and 2.7k-4.7k with the throttle open, when a smooth progression as the throttle opens.
If AFR is too far out of range, the o2 cannot pull it back to 14.7. Might test the temp sensor at the DME (to check both the sensor and the harness). Confirm DME pin 13 has 1.4k-3.6k at ambient temp and 160-210 ohms at 100c.
If you have a spare DME handy, try it.
Confirm that the regional coding plug is not installed, as this could put you into race gase maps which may or may not use the close loop system.
Confirm that you have zero exhaust leaks in front of or near the o2 sensor, as those can (and will) throw off your readings and cause you to chase your tail.
I simply attached the O2 sensor signal wire (green shielded wire) to the logger 0-5V input. Doesn't seem to disturb the signal since the behaviour didn't change.
When in closed loop it changes from app 0.16to 0.7 V with regular intervals, when out of closed loop it just stays at 0.8V indicating a rich mixture.
I measured the TPS at the DME connector and it is within spec and the idle switch works as well. I also log it so I can see that there aren't any dips or disruptions.
Haven't checked the full load signal but will check it next time
I measured the DME temp sensor at the DME connector and it is within spec.
I've checked for exhaust leaks but haven't found any. I think that if there were leaks between headers and turbo that wouldn't affect AFR since that side is under pressure. It's tricky to check the downpipe to exhaust but I think that a leak here would cause lean readings since it would draw in O2 rich air.
/Dea
08-28-2011, 04:40 PM
#17
Rennlist Member
Which pin in the piggyback did you connect the NB wire to?
Have you confirmed your DME harness does not have the regional coding plug installed?
Not sure which Vitesse system you have? If you have a Vitesse MAP sensor, have you made the necessary changes inside the DME and disconnected the Altitude sensor?
Was your car in closed loop properly before installing the MAF?
Yes, an exhaust leak at the downpipe will cause the wideband to read leaner in my experience.
Have you confirmed your DME harness does not have the regional coding plug installed?
Not sure which Vitesse system you have? If you have a Vitesse MAP sensor, have you made the necessary changes inside the DME and disconnected the Altitude sensor?
Was your car in closed loop properly before installing the MAF?
Yes, an exhaust leak at the downpipe will cause the wideband to read leaner in my experience.
08-28-2011, 05:41 PM
#18
Racer
Thread Starter
Which pin in the piggyback did you connect the NB wire to?
Have you confirmed your DME harness does not have the regional coding plug installed?
Not sure which Vitesse system you have? If you have a Vitesse MAP sensor, have you made the necessary changes inside the DME and disconnected the Altitude sensor?
Was your car in closed loop properly before installing the MAF?
Yes, an exhaust leak at the downpipe will cause the wideband to read leaner in my experience.
Have you confirmed your DME harness does not have the regional coding plug installed?
Not sure which Vitesse system you have? If you have a Vitesse MAP sensor, have you made the necessary changes inside the DME and disconnected the Altitude sensor?
Was your car in closed loop properly before installing the MAF?
Yes, an exhaust leak at the downpipe will cause the wideband to read leaner in my experience.
No regional plug or altitude sensor (euro cars don't have that ) and the correct resistor has been removed, all checked and verified by measuring at DME connector.
Not sure if it was correctly in closed loop before the change. They have only checked at idle at the inspections the last two years.
I should probably check fuel pressure to make sure it is correct. I assume it should decrease at vacuum the same way it increases at boost so the differential pressure always is 3 bar?
Dea
09-04-2011, 09:49 AM
#19
Racer
Thread Starter
More tests and more confusion...
Since it's somehow temp related I again measured the DME temp sensor but it's well within spec.
Tested the full load signal at 2500rpm both when the car still was cold and in closed-loop and when it was warm and in open loop and it was 4.96V and dropped to 0V at full throttle so that is OK.
Noticed two things:
1)
The TPS stayed att 1.2 kOhm from app. 1/3 to full throttle opening but since the throttle is just app. 10% open when testing at 2500rpm this shouldn't matter. After some more testing I turned out to be some oxidation or similar since it again showed values within spec and with smooth progression.
2)
When I tested to change map on the chip board to a non V-flex map I suddenly didn't have closed-loop at idle and around 16.5 AFR. Changed back to the map I just used just to find out that closed-loop idle was gone there as well but the AFR was better, around 15.0. After a while it went back to close loop but then dropped out again.
When at 16.5 AFR the NB sensor voltageat idle was around 0.2 V and 2500 rpm at 0.8V but no closed-loop behaviour.
WHen at AFR 15 the MB sensor was at 0.25 V and no closed-loop behaviour.
Since there aren't any more temperature related sensors in the system to test I suspect that either the NB-sensor is broken, something in the DME lambda regulation is broken or I have disturbances from the Zeitroniz connections.
I also tested that the NB-signal actually reaches the DME.
Is the NB sensor a standard 3-wire sensor? Is the connector proprietary?
Unfortunately I don't have a spare DME.
/Dea
Since it's somehow temp related I again measured the DME temp sensor but it's well within spec.
Tested the full load signal at 2500rpm both when the car still was cold and in closed-loop and when it was warm and in open loop and it was 4.96V and dropped to 0V at full throttle so that is OK.
Noticed two things:
1)
The TPS stayed att 1.2 kOhm from app. 1/3 to full throttle opening but since the throttle is just app. 10% open when testing at 2500rpm this shouldn't matter. After some more testing I turned out to be some oxidation or similar since it again showed values within spec and with smooth progression.
2)
When I tested to change map on the chip board to a non V-flex map I suddenly didn't have closed-loop at idle and around 16.5 AFR. Changed back to the map I just used just to find out that closed-loop idle was gone there as well but the AFR was better, around 15.0. After a while it went back to close loop but then dropped out again.
When at 16.5 AFR the NB sensor voltageat idle was around 0.2 V and 2500 rpm at 0.8V but no closed-loop behaviour.
WHen at AFR 15 the MB sensor was at 0.25 V and no closed-loop behaviour.
Since there aren't any more temperature related sensors in the system to test I suspect that either the NB-sensor is broken, something in the DME lambda regulation is broken or I have disturbances from the Zeitroniz connections.
I also tested that the NB-signal actually reaches the DME.
Is the NB sensor a standard 3-wire sensor? Is the connector proprietary?
Unfortunately I don't have a spare DME.
/Dea
09-04-2011, 01:43 PM
#20
Rennlist Member
It's hard to follow exactly what the problem is. Can you describe at a higher level what problem you are experiencing?
If you think you have a problem with the NB sensor, you could always use the simulated narrow band signal from the zeitronix in lieu of the factory wideband sensor.
If you think you have a problem with the NB sensor, you could always use the simulated narrow band signal from the zeitronix in lieu of the factory wideband sensor.
09-04-2011, 02:11 PM
#21
Racer
Thread Starter
The problem is that when the engine has reached normal operating temperature I get incorrect AFRs at all rpms except idle when testing at no load (car standing still).
Based on my testing the reason for this is that it is running in open-loop.
Before the engine reaches normal operating temperature the AFRs are correct at all rpms at no load and it is running in closed loop.
I'm in a catch 22 situation. The car hasn't passed the annual Swedish vehicle inspection so I can't do any road testing and to pass I need to have correct AFRs at idle and 2500 rpm.
/Dea
Based on my testing the reason for this is that it is running in open-loop.
Before the engine reaches normal operating temperature the AFRs are correct at all rpms at no load and it is running in closed loop.
I'm in a catch 22 situation. The car hasn't passed the annual Swedish vehicle inspection so I can't do any road testing and to pass I need to have correct AFRs at idle and 2500 rpm.
/Dea
Last edited by Dea_944t; 09-04-2011 at 02:44 PM.
09-04-2011, 04:57 PM
#22
Rennlist Member
Ok, got it. Are you sure you're not just a little lean across the board? When properly tuned, a cold 951 will run richer than 14.7 for the first minute or two. Have you tried adding to the global analog setting to richen things up? It may be just too lean to get into closed loop once warm?
09-05-2011, 02:53 AM
#23
Racer
Thread Starter
I'm running without the PB since it had some issues.
When the engine reaches normal operating temperature and it drops out of closed loop operation it runs very rich, AFR at 12, at all rpms except idle.
When logging the NB sensor it is easy to see that there is no closed loop regulation.
/Dea
When the engine reaches normal operating temperature and it drops out of closed loop operation it runs very rich, AFR at 12, at all rpms except idle.
When logging the NB sensor it is easy to see that there is no closed loop regulation.
/Dea
09-05-2011, 10:06 AM
#24
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Dea,
Ever since you purchased these used parts you have been having installation and now running issues. Have you contacted the previous owner to verify that he did not have the same issues? At this stage it's impossible to tell what is causing what. Are the issues caused with the installation, the car or the components?
The software operates in closed loop! If you do not see the O2 sensor dithering, then you are off the scale one way or the other.
Once the engine reaches operating temperature, and you notice the rich AFRs at 2500RPM. While maintaining 2500RPM, turn on the AC, heater blower and headlights. How does it affect your AFRs?
Ever since you purchased these used parts you have been having installation and now running issues. Have you contacted the previous owner to verify that he did not have the same issues? At this stage it's impossible to tell what is causing what. Are the issues caused with the installation, the car or the components?
The software operates in closed loop! If you do not see the O2 sensor dithering, then you are off the scale one way or the other.
Once the engine reaches operating temperature, and you notice the rich AFRs at 2500RPM. While maintaining 2500RPM, turn on the AC, heater blower and headlights. How does it affect your AFRs?
09-05-2011, 02:23 PM
#25
Racer
Thread Starter
John,
I have checked with previous owners and they didn't have these issues.
But you're correct, of all the things I've changed/installed on the car over the years (and that's a lot) this is by far the most problematic one.... and lookin back I wish I had bought new parts.
But things are what they are and I can either find the problem, buy a new kit or go back to the AFM set-up.
Since I'm not sure that going back to the AFM, or getting a new kit, will actually solve the problem since the it could be related to a sensor, DME&KLR, broken cabling etc. I 'll continue the fault finding until there's nothing left to test....
Since idle is really good and AFRs are OK as long as the engine is cold I have assumed that most things (MAF, injectors, MAP) are working properly.
Haven't tested turning on the AC etc. but will do that next time.
Will also connect the Zeitronix NB output to the NB DME input. The NB is the only sensor I haven't verified as OK.
/Dea
I have checked with previous owners and they didn't have these issues.
But you're correct, of all the things I've changed/installed on the car over the years (and that's a lot) this is by far the most problematic one.... and lookin back I wish I had bought new parts.
But things are what they are and I can either find the problem, buy a new kit or go back to the AFM set-up.
Since I'm not sure that going back to the AFM, or getting a new kit, will actually solve the problem since the it could be related to a sensor, DME&KLR, broken cabling etc. I 'll continue the fault finding until there's nothing left to test....
Since idle is really good and AFRs are OK as long as the engine is cold I have assumed that most things (MAF, injectors, MAP) are working properly.
Haven't tested turning on the AC etc. but will do that next time.
Will also connect the Zeitronix NB output to the NB DME input. The NB is the only sensor I haven't verified as OK.
/Dea
09-05-2011, 03:34 PM
#26
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It appears that you have multiple issues.. Too bad you are not able to use the PB, I was under the impression you sorted out the connection.
It appears that there are multiple issues, just need to sort through them.
As I mentioned in a earlier post, you may have a voltage drop in the signal between MAF and DME.. Which causes the lean @ idle.
The Rich at 2500 is a different issue. Post your test results when running the AC....
It appears that there are multiple issues, just need to sort through them.
As I mentioned in a earlier post, you may have a voltage drop in the signal between MAF and DME.. Which causes the lean @ idle.
The Rich at 2500 is a different issue. Post your test results when running the AC....
John,
I have checked with previous owners and they didn't have these issues.
But you're correct, of all the things I've changed/installed on the car over the years (and that's a lot) this is by far the most problematic one.... and lookin back I wish I had bought new parts.
But things are what they are and I can either find the problem, buy a new kit or go back to the AFM set-up.
Since I'm not sure that going back to the AFM, or getting a new kit, will actually solve the problem since the it could be related to a sensor, DME&KLR, broken cabling etc. I 'll continue the fault finding until there's nothing left to test....
Since idle is really good and AFRs are OK as long as the engine is cold I have assumed that most things (MAF, injectors, MAP) are working properly.
Haven't tested turning on the AC etc. but will do that next time.
Will also connect the Zeitronix NB output to the NB DME input. The NB is the only sensor I haven't verified as OK.
/Dea
I have checked with previous owners and they didn't have these issues.
But you're correct, of all the things I've changed/installed on the car over the years (and that's a lot) this is by far the most problematic one.... and lookin back I wish I had bought new parts.
But things are what they are and I can either find the problem, buy a new kit or go back to the AFM set-up.
Since I'm not sure that going back to the AFM, or getting a new kit, will actually solve the problem since the it could be related to a sensor, DME&KLR, broken cabling etc. I 'll continue the fault finding until there's nothing left to test....
Since idle is really good and AFRs are OK as long as the engine is cold I have assumed that most things (MAF, injectors, MAP) are working properly.
Haven't tested turning on the AC etc. but will do that next time.
Will also connect the Zeitronix NB output to the NB DME input. The NB is the only sensor I haven't verified as OK.
/Dea
09-05-2011, 03:49 PM
#27
Racer
Thread Starter
Sorry for not being clear, have tested so many things I'm starting to mix them up....
At idle the AFR without PB is perfect, steady at 14.6-14.8, both when the engine is hot and cold.
The issue is rich AFRs at all rpms above idle when the engine is warm.
I sorted out the connection, the serial adapters driver didn't work correctly with Windows 7, using another adapter with a specific Windows 7 driver solved the issue.
Unfortunately there seems to be some other issues with the PB so to make fault finding easier I decided to continue testing without it.
/Dea
At idle the AFR without PB is perfect, steady at 14.6-14.8, both when the engine is hot and cold.
The issue is rich AFRs at all rpms above idle when the engine is warm.
I sorted out the connection, the serial adapters driver didn't work correctly with Windows 7, using another adapter with a specific Windows 7 driver solved the issue.
Unfortunately there seems to be some other issues with the PB so to make fault finding easier I decided to continue testing without it.
/Dea
09-05-2011, 06:02 PM
#28
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Ok, if Idle is fine, let's forget about it for now. Let us know the results of the 2500RPM test when you turn on the AC/Blower/Headlights...
09-11-2011, 08:51 AM
#29
Racer
Thread Starter
Did two tests today:
1)
Used the Zeitronix simulated narrowband output as input to DME instead of the original lambda sensor to rule out any faults in it.
The behaviour did not change so warm and cold idle AFR is 14.7 and 2500 rpm, actually any rpm above idle, AFR is 14.7 when cold and 12.0 when warm.
The attached log shows that it is no longer in closed loop at 2500rpm.
User 1 at the bottom is logging the lambda value (in this case the output from the Zeitronix narrowband simulation)
2)
Held the engine at 2500rpm and turned on headlight, full blower and AC.
The AFR then changed from app. 12 to 13.5-14.0.
Not sure what conclusion to draw from this, I hope John can help with some insight.
I've decided to take it to the annual inspection anyway, it seems that if I fail I get a one month period where I'm allowed to drive the car. Being able to do some actual road testning might make it easier to find the fault.
I also think that I will get the new MoMonitor.
/Dea
1)
Used the Zeitronix simulated narrowband output as input to DME instead of the original lambda sensor to rule out any faults in it.
The behaviour did not change so warm and cold idle AFR is 14.7 and 2500 rpm, actually any rpm above idle, AFR is 14.7 when cold and 12.0 when warm.
The attached log shows that it is no longer in closed loop at 2500rpm.
User 1 at the bottom is logging the lambda value (in this case the output from the Zeitronix narrowband simulation)
2)
Held the engine at 2500rpm and turned on headlight, full blower and AC.
The AFR then changed from app. 12 to 13.5-14.0.
Not sure what conclusion to draw from this, I hope John can help with some insight.
I've decided to take it to the annual inspection anyway, it seems that if I fail I get a one month period where I'm allowed to drive the car. Being able to do some actual road testning might make it easier to find the fault.
I also think that I will get the new MoMonitor.
/Dea
09-18-2011, 09:33 AM
#30
Racer
Thread Starter
This weekends testing...
- Tested all FQS positions, no improvement
- Hooked up a DVM to pin 7 and ground on the DME to check MAF voltage:
idle 0.66V
2000rpm 0.84V
2500rpm 1.0V
3000rpm 1.1V
It would be great if someone could confirm that these are OK values
- Measured DME pin 22, Air flow NTC input, yellow wire on MAF
4.11-4.18V no changes depending on rpm
- Let it run on idle for an extended period of time
Sometimes it drops out of closed loop also at idle. The lambda sensor clearly indicates lean (0.08V) so it should regulate. The AFR is still OK at 15.0.
After all this testing I still have no good clues.
It is clear that the engine has a problem with closed loop operation when it's warm at all rpms above idle and sometimes at idle as well (but then the FAR stays OK).
I have tested all sensors and measured all the cabling several times so I can only come to the conclusion that either the DME is broken or there is something wrong with the chip board.
I was thinking of getting a MoMonitor to make it easier to track the fault but I'm not sure if it will give enough detail?
Some items I haven't checked:
- Injector flow, but I think this should affect idle as well
- Fuel pressure
- Tesing with another DME
Any more ideas before I go back to the AFM set-up?
/Dea
- Tested all FQS positions, no improvement
- Hooked up a DVM to pin 7 and ground on the DME to check MAF voltage:
idle 0.66V
2000rpm 0.84V
2500rpm 1.0V
3000rpm 1.1V
It would be great if someone could confirm that these are OK values
- Measured DME pin 22, Air flow NTC input, yellow wire on MAF
4.11-4.18V no changes depending on rpm
- Let it run on idle for an extended period of time
Sometimes it drops out of closed loop also at idle. The lambda sensor clearly indicates lean (0.08V) so it should regulate. The AFR is still OK at 15.0.
After all this testing I still have no good clues.
It is clear that the engine has a problem with closed loop operation when it's warm at all rpms above idle and sometimes at idle as well (but then the FAR stays OK).
I have tested all sensors and measured all the cabling several times so I can only come to the conclusion that either the DME is broken or there is something wrong with the chip board.
I was thinking of getting a MoMonitor to make it easier to track the fault but I'm not sure if it will give enough detail?
Some items I haven't checked:
- Injector flow, but I think this should affect idle as well
- Fuel pressure
- Tesing with another DME
Any more ideas before I go back to the AFM set-up?
/Dea