Vitesse MAF voltage vs rpm and AFR?
03-26-2012, 11:20 AM
#16
I just checked one of my logs (SMT8 w/ V-MAF+) at idle and I am showing a MAF voltage of around 0.56 to 0.59 volts. A MAF voltage of 1V at 2700 rpm with hardly any load looks reasonable to me as well.
03-26-2012, 11:44 AM
#17
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Good advise.
You are correct. Not having the car, makes things more of a challenge, but it's not impossible. When dealing with items/parts that are a few years old, parts that exchanged hands, adds another level of difficulty as the condition of the parts is unknown. In this case we are talking 4-5 years old items, not sure how many times the parts exchanged hands (at least once).
Even though, prior owners did not experience similar problems, back in Sep. of last year, I suggested to have Dea send in the parts so I can examine the parts. (which may still happen id Dea chooses to do so).
We rely on the end user to be our eyes and ears. However, at times it may be a bit more difficult than others. We have been working with Dea to sort out some of the issues with his used parts, as detailed in older threads: Here and Here
When dealing with the "same" issue, I think it would be beneficial to keep a single thread going, otherwise it becomes time consuming to analyze the multiple threads.
Considering the low voltages we are dealing with, there are a few variables that will alter the signal. Engine VE, outside consditions and temps,.. will cause the voltage to vary some... Based on what Dea posted, I do not see anything that "jumps out", which makes things more interesting.
This will be a good test. He also has the PB so he can try adjusting a particular area. However, there is a possibility he can be masking out a underlying problem. The behavior he is experiencing was not experienced by prior owner(s). Of course, fine tuning is always a option.
Based on Dea's older thread, his car (ROW) did not originally have closed loop. He also experimented with "simulated" narrow band output from his WB system. Yet, another variable to the equation!
In Dea's older threads, a few more tests were done. It may be a good idea to join both threads so we are looking at the big picture.
Dea_944t, Can you join your threads? It makes things much easier, so we don't have to revisit the same things over and over.
Considering the variables we are dealing with, I think testing the components to verify their condition should have a high priority at this stage.
If you have any questions, feel free to drop me a email.
Even though, prior owners did not experience similar problems, back in Sep. of last year, I suggested to have Dea send in the parts so I can examine the parts. (which may still happen id Dea chooses to do so).
We rely on the end user to be our eyes and ears. However, at times it may be a bit more difficult than others. We have been working with Dea to sort out some of the issues with his used parts, as detailed in older threads: Here and Here
When dealing with the "same" issue, I think it would be beneficial to keep a single thread going, otherwise it becomes time consuming to analyze the multiple threads.
FWIW, you are only .4V above your no load idle MAF V reading... not terribly bad, but I will cross check it for you this evening.
I have on my laptop at home logs from both a Vitesse system and a non-vitesse system, on 2 seperate cars, simmilar enough in setup to be points of refference for you, and insrumented identical to yours... I will check their logs when I get home, and post results.
ALSO, for refference, can you post a WOT high RPM log point just for cross refference to the other logs?
I have on my laptop at home logs from both a Vitesse system and a non-vitesse system, on 2 seperate cars, simmilar enough in setup to be points of refference for you, and insrumented identical to yours... I will check their logs when I get home, and post results.
ALSO, for refference, can you post a WOT high RPM log point just for cross refference to the other logs?
Considering the low voltages we are dealing with, there are a few variables that will alter the signal. Engine VE, outside consditions and temps,.. will cause the voltage to vary some... Based on what Dea posted, I do not see anything that "jumps out", which makes things more interesting.
In Dea's older threads, a few more tests were done. It may be a good idea to join both threads so we are looking at the big picture.
Dea_944t, Can you join your threads? It makes things much easier, so we don't have to revisit the same things over and over.
Considering the variables we are dealing with, I think testing the components to verify their condition should have a high priority at this stage.
If you have any questions, feel free to drop me a email.
Last edited by fast951; 03-26-2012 at 12:14 PM.
03-26-2012, 11:53 AM
#18
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Good data points. In Dea's previous thread I noticed that his Idle voltage was a bit higher, but he was running lean. Then "something" changed and it's running rich now. So there is inconsistency, which makes it more challenging.
03-26-2012, 02:37 PM
#19
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Thread Starter
Thanks for all the input!
In short the car shows OK AFR values and a working closed loop O2 at idle and at cruise driving.
The 2500 rpm "idle" is way rich and this is a problem since this is emission test point in Sweden.
I have only tested 7 psi boost so far and I've attached a log of that, User 1 input is the lambda voltage.
I started a new thead as the old one was a bit messy... and I've narrowed the problem down a bit.
I've tested all the normal stuff:
- ground potential measurements with engine running
- connectivity/resistance test of all cables
- measured all temp sensors, TPS etc. hot and cold
- tested with a different DME (28-pin modified from a non-cat car if that matters)
- used the ZT-2 narrowband output instead of the original lambda sensor
I'm currently running without the PB to try to minimize the error sources
I've tried changing the FQS one step but it didn't change much.
It's a closed loop O2 system and it works at idle and at actual driving cruise conditions but fails to work at 2500 rpm idle
This is interesting. Do you have a closed loop O2 system? if so it would be good to know your AFR at 2500 "idle"
I'll post logs with different FQS after the weekend.
Great, thanks!
It's a bit tricky to get logs as it's illegal to drive the car right now and it's in the middle of the city.... I've posted an almost WOT 7 psi run but without MAF voltage.
Will try to get a log with MAF voltage asap.
Thanks! looks to be consistent with my values
/Dea
In short the car shows OK AFR values and a working closed loop O2 at idle and at cruise driving.
The 2500 rpm "idle" is way rich and this is a problem since this is emission test point in Sweden.
I have only tested 7 psi boost so far and I've attached a log of that, User 1 input is the lambda voltage.
I started a new thead as the old one was a bit messy... and I've narrowed the problem down a bit.
I've tested all the normal stuff:
- ground potential measurements with engine running
- connectivity/resistance test of all cables
- measured all temp sensors, TPS etc. hot and cold
- tested with a different DME (28-pin modified from a non-cat car if that matters)
- used the ZT-2 narrowband output instead of the original lambda sensor
I'm currently running without the PB to try to minimize the error sources
I have the Vitesse MAF and ZT-2, but I haven't done any logging yet. I have watched the AFR's extensively, but only once have I measured the MAF output voltage and I don't remember off the top of my head what it was. Here's all I can tell you:
1) At no load, the AFR vs. RPM curve seems consistent with mine.
2) Once I got my grounding issues sorted, my AFR's were too lean. I had to adjust my FQS switch to compensate. I tried FQS number three first (+6%), but on boost my AFR would drop into the 10's. I backed it off to FQS number one (+3%), and now my AFR's are 14.6-14.7 idle, 12.7-13.1 cruising (no boosting, very low load), and always right at 11.5 on boost.
My recommendation is to go to FQS 1 and post the log. If you need me to measure the MAF output voltage for reference, please just remind me which wires to probe and I'll get a visual on it for you.
1) At no load, the AFR vs. RPM curve seems consistent with mine.
2) Once I got my grounding issues sorted, my AFR's were too lean. I had to adjust my FQS switch to compensate. I tried FQS number three first (+6%), but on boost my AFR would drop into the 10's. I backed it off to FQS number one (+3%), and now my AFR's are 14.6-14.7 idle, 12.7-13.1 cruising (no boosting, very low load), and always right at 11.5 on boost.
My recommendation is to go to FQS 1 and post the log. If you need me to measure the MAF output voltage for reference, please just remind me which wires to probe and I'll get a visual on it for you.
I'll post logs with different FQS after the weekend.
He is indicating in mm Hg, not PSI...
Seriously guys? Not only has this discussion been beaten to death, but is totally off subject...
ON subject, OP, I answered you on another forum, but will answer here as well..
FWIW, you are only .4V above your no load idle MAF V reading... not terribly bad, but I will cross check it for you this evening.
I have on my laptop at home logs from both a Vitesse system and a non-vitesse system, on 2 seperate cars, simmilar enough in setup to be points of refference for you, and insrumented identical to yours... I will check their logs when I get home, and post results.
ALSO, for refference, can you post a WOT high RPM log point just for cross refference to the other logs?
Seriously guys? Not only has this discussion been beaten to death, but is totally off subject...
ON subject, OP, I answered you on another forum, but will answer here as well..
FWIW, you are only .4V above your no load idle MAF V reading... not terribly bad, but I will cross check it for you this evening.
I have on my laptop at home logs from both a Vitesse system and a non-vitesse system, on 2 seperate cars, simmilar enough in setup to be points of refference for you, and insrumented identical to yours... I will check their logs when I get home, and post results.
ALSO, for refference, can you post a WOT high RPM log point just for cross refference to the other logs?
It's a bit tricky to get logs as it's illegal to drive the car right now and it's in the middle of the city.... I've posted an almost WOT 7 psi run but without MAF voltage.
Will try to get a log with MAF voltage asap.
/Dea
Last edited by Dea_944t; 03-26-2012 at 03:21 PM.
03-26-2012, 03:20 PM
#20
Racer
Thread Starter
Good advise.
You are correct. Not having the car, makes things more of a challenge, but it's not impossible. When dealing with items/parts that are a few years old, parts that exchanged hands, adds another level of difficulty as the condition of the parts is unknown. In this case we are talking 4-5 years old items, not sure how many times the parts exchanged hands (at least once).
Even though, prior owners did not experience similar problems, back in Sep. of last year, I suggested to have Dea send in the parts so I can examine the parts. (which may still happen id Dea chooses to do so).
We rely on the end user to be our eyes and ears. However, at times it may be a bit more difficult than others. We have been working with Dea to sort out some of the issues with his used parts, as detailed in older threads: Here and Here
When dealing with the "same" issue, I think it would be beneficial to keep a single thread going, otherwise it becomes time consuming to analyze the multiple threads.
Considering the low voltages we are dealing with, there are a few variables that will alter the signal. Engine VE, outside consditions and temps,.. will cause the voltage to vary some... Based on what Dea posted, I do not see anything that "jumps out", which makes things more interesting.
This will be a good test. He also has the PB so he can try adjusting a particular area. However, there is a possibility he can be masking out a underlying problem. The behavior he is experiencing was not experienced by prior owner(s). Of course, fine tuning is always a option.
Based on Dea's older thread, his car (ROW) did not originally have closed loop. He also experimented with "simulated" narrow band output from his WB system. Yet, another variable to the equation!
In Dea's older threads, a few more tests were done. It may be a good idea to join both threads so we are looking at the big picture.
Dea_944t, Can you join your threads? It makes things much easier, so we don't have to revisit the same things over and over.
Considering the variables we are dealing with, I think testing the components to verify their condition should have a high priority at this stage.
If you have any questions, feel free to drop me a email.
You are correct. Not having the car, makes things more of a challenge, but it's not impossible. When dealing with items/parts that are a few years old, parts that exchanged hands, adds another level of difficulty as the condition of the parts is unknown. In this case we are talking 4-5 years old items, not sure how many times the parts exchanged hands (at least once).
Even though, prior owners did not experience similar problems, back in Sep. of last year, I suggested to have Dea send in the parts so I can examine the parts. (which may still happen id Dea chooses to do so).
We rely on the end user to be our eyes and ears. However, at times it may be a bit more difficult than others. We have been working with Dea to sort out some of the issues with his used parts, as detailed in older threads: Here and Here
When dealing with the "same" issue, I think it would be beneficial to keep a single thread going, otherwise it becomes time consuming to analyze the multiple threads.
Considering the low voltages we are dealing with, there are a few variables that will alter the signal. Engine VE, outside consditions and temps,.. will cause the voltage to vary some... Based on what Dea posted, I do not see anything that "jumps out", which makes things more interesting.
This will be a good test. He also has the PB so he can try adjusting a particular area. However, there is a possibility he can be masking out a underlying problem. The behavior he is experiencing was not experienced by prior owner(s). Of course, fine tuning is always a option.
Based on Dea's older thread, his car (ROW) did not originally have closed loop. He also experimented with "simulated" narrow band output from his WB system. Yet, another variable to the equation!
In Dea's older threads, a few more tests were done. It may be a good idea to join both threads so we are looking at the big picture.
Dea_944t, Can you join your threads? It makes things much easier, so we don't have to revisit the same things over and over.
Considering the variables we are dealing with, I think testing the components to verify their condition should have a high priority at this stage.
If you have any questions, feel free to drop me a email.
I really appreciate the help I have received from you so far and the offer to test the components!
I want to be as sure as I can be that I haven't missed something simple before sending the components to you so I'm trying to test the last couple of things I can think of (we had an early winter so I had to quit testing last year).
The car actually has closed loop O2 (mandatory from 1989).
My idea was to start a new thread since the old one was a bit messy. I'll see if it makes sense to merge them.
/Dea
