ECMlink Jumpy logged items after gm maf install please help! dsmlink v3

[DSM-Franek]

I recently went from a 2g mas to a 3" gm maf with the dsmlink cable and in logs my airflow and some other things even my WBO2 get jumpy at about 6k rpm.

I attached my most recent log with the stock 2g mas (log.2009.05.12-01.elg) and a log from today with the gm maf (log.2009.05.17-01.elg)

Any ideas what may be causing this?

Thanks in advance!
Frank

 

[DSM-Franek]

Does this look like it could be surge? Or would a boost leak do this?

Thanks in advance,
Frank

 

[snowborder714]

Do not bump your thread.

Is that the only thing you changed at the time (remove 2g MAS and install 3" GM MAF)?

I would say to do a boost leak test anyway.

 

[ed_dogg23]

Personally I experience the same thing with all the gm maf cars I've tuned. I've also performed a few boost leaks on my car to no avail. Id say its just the way the gm maf reacts to boosted applications. The spike in your wide band is reacion in the airflow change. If you logged idc's you would see them change or fluctuate in the same manner. Good luck with the tune and keep us posted!!!

 

[DSM-Franek]

Do not bump your thread.

Is that the only thing you changed at the time (remove 2g MAS and install 3" GM MAF)?

I would say to do a boost leak test anyway.

I'm sorry I should have edited my 1st post. But yes that's the only thing I changed.

Personally I experience the same thing with all the gm maf cars I've tuned. I've also performed a few boost leaks on my car to no avail. Id say its just the way the gm maf reacts to boosted applications. The spike in your wide band is reacion in the airflow change. If you logged idc's you would see them change or fluctuate in the same manner. Good luck with the tune and keep us posted!!!

I believe IDC's are logged I cannot check right now however because I don't have link on my computer at work

 

[DSM-Franek]

Okay, so I attempted to smooth things out but going into the direct access tables and bringing the off idle airflow smoothing from 87.9% to 91% and that didn't help at all. If anything it may be worse.

I also richened it up a bit to be safe while I'm trying to figure out this issue and I think that made my boost rise as seen in the AEM 3.5bar map that is logged.

Any ideas?

ps. This is a brand new GM 3" maf if that makes any difference.

Thanks for the help so far!
Frank

 

[ed_dogg23]

Hey bro, I just took a look at your log and I wanted to suggest a few things. First off under your mafcomp the adjustments you made should be made smoother so that they are not so jagged. I also would suggest that you log maf raw. This will help with knowing where futher adjustments should be made. Your wb also went pretty rich and this is where I belive where that knock could be taken care of.

Please understand that these are just suggetions and in no way am I telling you that I dont think you know what you are doing, and if you would like more help I would be more that happy to assist in any way I can!!!!!

 

[snowborder714]

One thing I note is that you have "Activate fuel pump" checked. You might want to uncheck this, as I would think it would keep your fuel pump on, even if the key is in the ON position and the car not started.

You might also want to try checking "Lock intake temperature and barometric pressure" in the ECU Inputs tab.

 

[ed_dogg23]

One thing I note is that you have "Activate fuel pump" checked. You might want to uncheck this, as I would think it would keep your fuel pump on, even if the key is in the ON position and the car not started.

You might also want to try checking "Lock intake temperature and barometric pressure" in the ECU Inputs tab.

Would locking this help with the movment of the maf signal?

 

[snowborder714]

That I am not sure. I know when using the translator box, you had to do this or the car would act weird I believe. I am not sure how this works with the cable, but I would guess the same?

 

[ed_dogg23]

I would absolutley assume so! I will post two logs tomorrow then so we can actually see. I would love to see it smooth out, and it would help in the next tunes that I get to be a part of!

 

[DSM-Franek]

Hey bro, I just took a look at your log and I wanted to suggest a few things. First off under your mafcomp the adjustments you made should be made smoother so that they are not so jagged. I also would suggest that you log maf raw. This will help with knowing where futher adjustments should be made. Your wb also went pretty rich and this is where I belive where that knock could be taken care of.

Please understand that these are just suggetions and in no way am I telling you that I dont think you know what you are doing, and if you would like more help I would be more that happy to assist in any way I can!!!!!

Hey man, thanks alot for taking the time to help! I will go ahead and smooth those mafcomp points out and MAFraw is logged.

One thing I note is that you have "Activate fuel pump" checked. You might want to uncheck this, as I would think it would keep your fuel pump on, even if the key is in the ON position and the car not started.

You might also want to try checking "Lock intake temperature and barometric pressure" in the ECU Inputs tab.

I don't see any issue in having the fuel pump prime before a start or is there something bad that this could cause

Also, I believe intake and barometric pressure automatically lock when you choose "3" gm maf" in the base maf type settings based on my intake temps in the logs.

Thanks for the help so far!

 

[ed_dogg23]

Now I see mafraw is captured. Now you should display it when you log. This way you can tell where to make adjustments to the maf.

 

[DSM-Franek]

Now I see mafraw is captured. Now you should display it when you log. This way you can tell where to make adjustments to the maf.

It is displayed over here . Maybe you just had to add it on your displayed values?

Do you think I should lock intake air temp and baro and see if that does anything to smooth the airflow?

Thanks
Frank

 

[ed_dogg23]

It is displayed over here . Maybe you just had to add it on your displayed values?

Do you think I should lock intake air temp and baro and see if that does anything to smooth the airflow?

Thanks
Frank

Yes sir. Now display values. I locked the air temp this morrning on the way to work and the log did not change, as in the maf and est boost were still jumpy and what not. I wont even post it up since there is no difference, unless you guys want to see it. If so it will have to wait till I get home after work.

 

[snowborder714]

Have you done a boost leak test yet Frank?

 

[bling5tatus]

The GM MAF is KNOWN to have inaccurate/jumpy airflow readings when used in blow through configuration. This is very well documented. That is why so many people are ready to jump ship to the speed density configurations. I'm not saying, don't try to figure this out and fix it, I'm just saying that there have been many before you with the same issue.

 

[DSM-Franek]

Have you done a boost leak test yet Frank?

Honestly not yet since I went with the 3" gm maf setup. I am going to after work tomorrow though for sure though.

The GM MAF is KNOWN to have inaccurate/jumpy airflow readings when used in blow through configuration. This is very well documented. That is why so many people are ready to jump ship to the speed density configurations. I'm not saying, don't try to figure this out and fix it, I'm just saying that there have been many before you with the same issue.

But there are also many that have almost stock steadiness in their airflow curves with gm maf setups, which is what I am trying to get the closest I can too.

 

[DSM-Franek]

Okay I did a boost leak test and found a beastly leak where the two 3" ends bolt onto the black center (sensor) part of the gm maf. The 4 bolts are tight.

I found this EXTREME PSI : Your #1 Source for In Stock Performance Parts - GM MAF Sensor 3.0".

In the description "*Note: GM has gone through a revision on the 3.0" sensors that removed the inner seal. These sensors are no longer recommended for use in a blow-thru setup or in any situation where it would be under boost. Running this sensor on the intake side should be no problem. If you are looking for a sensor to be run on a blow-thru setup, please purchase the 3.50" GM sensor."

Does this mean I'm screwed for buying a brand new 3" and couplers and t-bolts?

Anyone know? Or have experience with brand new 3" gm mafs?

Any info is greatly appreciated!

edit: I think I may just JB weld the hell out of the seams where the ends meet the plastic sensor itself. May not be pretty but it sure as hell won't leak!

 

[ed_dogg23]

Okay I did a boost leak test and found a beastly leak where the two 3" ends bolt onto the black center (sensor) part of the gm maf. The 4 bolts are tight.

I found this EXTREME PSI : Your #1 Source for In Stock Performance Parts - GM MAF Sensor 3.0".

In the description "*Note: GM has gone through a revision on the 3.0" sensors that removed the inner seal. These sensors are no longer recommended for use in a blow-thru setup or in any situation where it would be under boost. Running this sensor on the intake side should be no problem. If you are looking for a sensor to be run on a blow-thru setup, please purchase the 3.50" GM sensor."

Does this mean I'm screwed for buying a brand new 3" and couplers and t-bolts?

Anyone know? Or have experience with brand new 3" gm mafs?

Any info is greatly appreciated!

edit: I think I may just JB weld the hell out of the seams where the ends meet the plastic sensor itself. May not be pretty but it sure as hell won't leak!

Nice to know! Thank U

 

[snowborder714]

Um, just buy a used one. They work just as well and are a lot cheaper. Any junkyard should be able to find one for you off the massive list of applicable cars on here.

 

[Hal]

To smooth out the airflow signal when using the MAF-T cable, use the airflow smoothing panel found under the direct access tab.

 

[DSM-Franek]

To smooth out the airflow signal when using the MAF-T cable, use the airflow smoothing panel found under the direct access tab.

Yea I tried that. I upped it from the 87.9% to 91% and 94% with no luck.

I'll let you know what happens once the boost leak is fixed.

Thanks,
Frank

 

[Hal]

You might try reducing the number.

During beta testing of direct GM MAF support I found that it would take pretty big swings in one direction or another to determine which way it needed to go.

Your airflow is actually pretty smooth compared to some I've seen.

 

[bling5tatus]

So, Hal, what you're saying is... it gives inaccurate signals in blow through configuration?