MAF-T bogging help

[Littlebeeper]

I installed a Maf-t in my car and since i got it it seems to bog upon initial pushing of the gas pedal when taking off. If i take off normally giving a little gas there is no initial hesitation, but i do anything more that gradually give it gas i get a hesitation then she takes off. Even if i just idle and then just stomp on the gas the engine seems to get no gas for like a slit second then it revs up, if i hold RPM steady at like 1500 RPM and stomp it the hesitation is still there also. seems that it only happens at extremely rapid throttle increases. It also does it less when engine reached operating temp. MAF-T is version 1.3 not the latest if it matters. I have tried base settings of 0-2 with similar results. Maps were a little lean at setting 2, i currently have it at 0 with low trim at 82%(rich i know) Ideas? on the upside, the idle is now dead solid. it used to wander from 700-1000 RPM, now 850RPM solid.

 

[d1verDSM]

hey ! my maft T does the exact same thing , i have the newer model thow ,


i logged my car with my Wideband . and i have a perfect 14.7 AFR at idle , or cruise , when i press on the gas pedal midly fast , i get a bad bog , in every gear and from every start. My AFR during the bog , spikes too 18:1 or even as much as 24:1 , If im really (i mean really ) smooth on the gas , i dont get it . The bog last a fraction of a second , and the the car accelerates smothly. I dont know what the hell could be causing this


im running a s-afc maft (3.5inch gm maf) combo (drawtrue) with bov return to intake, 660cc ultimate racing injectors , 255 pump , stock FRP .


Whats your setup , maybe theres a common link

 

[d1verDSM]

execpt .. my low trim , is at 139 % WTf and my AFR is perfect 14.7:1

my base is set up for 660cc'S and my idle knob sits at zero my mid and high trim is 100 %

 

[d1verDSM]

it seems to bog upon initial pushing of the gas pedal when taking off.

If i take off normally giving a little gas there is no initial hesitation, but i do anything more that gradually give it gas i get a hesitation then she takes off. Even if i just idle and then just stomp on the gas the engine seems to get no gas for like a slit second then it revs up, if i hold RPM steady at like 1500 RPM and stomp it the hesitation is still there also. seems that it only happens at extremely rapid throttle increases. It also does it less when engine reached operating temp.

these problems are EXACTLY the same as mine

 

[Littlebeeper]

I'm stock on 450 injectors, don't want to push up the boost till i get this fixed. I have set the MAFT to F,0,1,2. when i was at 2 on base my trim was at 120%, now I'm at 0 and trim at 82%(both low trims) mid has been at 102% steadily and high at 100%. At all setting and at any RPM the engine bogs for a fraction of a second and then takes off. I only have a data logger and it really doesn't show anything wrong! This is really creeping me out. I'm running my MAF-T in a blow through set up with blow off valve vented to the atmosphere. The GM mas is a 3" and is located at least 6 inches from the TB elbow, by stock blow off valve is located about 6 inches above my sidemount intercooler. Hopefully we can get some help...seems that MAF-T version is not the problem. All setting are set to default (zero) and i do have the RPM wire connected to the CAS. Did the same thing with wire unplugged though.

 

[peregrine]

hey ! my maft T does the exact same thing , i have the newer model thow ,


i logged my car with my Wideband . and i have a perfect 14.7 AFR at idle , or cruise , when i press on the gas pedal midly fast , i get a bad bog , in every gear and from every start. My AFR during the bog , spikes too 18:1 or even as much as 24:1 , If im really (i mean really ) smooth on the gas , i dont get it . The bog last a fraction of a second , and the the car accelerates smothly. I dont know what the hell could be causing this


im running a s-afc maft (3.5inch gm maf) combo (drawtrue) with bov return to intake, 660cc ultimate racing injectors , 255 pump , stock FRP .


Whats your setup , maybe theres a common link

thats a lean tip in problem. im not sure what you can do about it with no dsmlink or anything like that.

 

[d1verDSM]

and what is a lean tip in condition ?

is there any guys here that have a fix or advice for fixing that , for us people that run only piggy backs

 

[Littlebeeper]

lean tip in is just as it sounds i guess. A brief lean condition at onset of load on the engine. This is pretty damn rare though. I searched this forum and the MAF-T forum with no luck. Maybe there is a glitch on our chip. or there is one more thing. When i was plugging in my translator i checked continuity between the MAS ground wire and the negative battery cable and it wasn't 100%. hope i can get you guys to understand. My multimeter drops from "---" which is about 1000 at no continuity touching nothing with the leads to "0" when touching the leads together. Normally i can get to zero or pretty damn close but with this MAS ground test i could only get to about 200 or about an 80% ground to the negative battery cable. The factory MAS worked just fine and never gave me any problems. maybe i'll try to jump a ground wire to my MAS-T to see if a better ground helps. Any other ideas, feel free to chime in. d1verDSM and I could use a brain storm to get this fixed. We should probably post at http://www.fullthrottletech.com/index.php after all they are the ones who make this thing

 

[Littlebeeper]

I asked for help at FullthrottleTech. Still waiting for a reply. The guys are at the SEMA show from what their website said. I'll post back if they have any suggestions

 

[jetdriven]

mine did it too and what fixed it was adding fuel in the 150-200 hz area with the mas compensation tables. it was going lean right before it went open loop. adding fuel in this area helped that.

 

[Littlebeeper]

just in case you never found your problem i pretty much fixed mine. I was going to replace the GM mas but decided to check my TPS as anything on these cars will leave you on the side of the road. Sure enough my logger had it at 10.5% at idle. adjested to 9.3 at idle and its pretty much gone. there is a really slight almost unknoticable hesitation but i'm sure adjusting the MAF-T (just reinstalled it as it was getting fixed) will get rid of it. haven't adjusted it yet

 

[Newlogics]

Had the same problem on my 1G as well. I tried everything for over a year now. From chaing AFR to orienting GM MAF differently. I got it down to just a small notch, but it's still there. I had to pull idle switch off to keep idle stable (my ICS had troubles with all my compensations), and that helpd the 'blip' in throttle response a lot. That little 'blip' still pisses me off though. As a matter of fact, about 80% of DSMS with GM MAFTs that come through our shop have that. And in those that don't, I couldn't find any differences in anything to pinpoint the solution or at least the cause.

 

[allgripnoslip]

is this more of a 1g problem?

 

[Newlogics]

is this more of a 1g problem?

I've dealt with several 2Gs with the same problem. It seems to be much less pronounced in 2Gs though...

 

[allgripnoslip]

I ask that because all 1g guys posted in here