Tuning help Maft 1.2

[fwdtsi]

Who here is just tuning with a MAFT version 1.2? Its very screwy on mine! I have been trying to tune it but cant figure anything out.... Its quit confusing becuase I went by te instructions which tell you base should be set -20% for 550's, I set this there and it was running rich so I went ended up going to -25% then -30%. At -25% it didnt knock to 20 psi but then -30% it would. I know how to tune kind of, but this is bugging me. I need to play with low,mid and WOT but I really dont know where to start....... My fuel trims are
FTRL 139.8% (all the time, wont change)
FTRM 94.5%
FTRH 103.1%
FTO2 100%
On 20psi, It will knock 10-15 counts. I have my Maft set at -25% base, -5% idle,-5% mid and -5% high, The confusing thing is every time I richen it up at top it will still knock but worse. Anybody that has 1.2 and is tuning with it please chime in.thanks

 

[fwdtsi]

I have a Air/fuel gauge which pegs to rich as soon as I hit the gas also, but I dont want to go by this

 

[kpt4321]

You need to work on your tuning. You claim that the low fuel trim won't move, but you have the idle knob set wrong. Richen the idle up a few clicks, and see what happens.

 

[fwdtsi]

See, thats the thing. If I richen idle it idles bad and it smells like a bass boat on start up. I think I just didnt give my car enough time to change the fuel trims, maybe?

 

[nine5raptor]

Originally posted by fwdtsi
I think I just didnt give my car enough time to change the fuel trims, maybe?

You will need to give it at least a couple of days on a 93.

Look at your 02 trims for instant feedback.

 

[fwdtsi]

A couple days? I thought a couple minutes!! Okay, so i guess thats it. thanks

 

[nine5raptor]

Originally posted by fwdtsi
A couple days? I thought a couple minutes!! Okay, so i guess thats it. thanks

I don't know for sure on a 93, but the 1Gs tend to be considerably slower than the 2g's when it comes to updating. I give mine at least a day or two to finally stabilize.

 

[robw22]

I also have a 93 with translator, My FTRL has been stuck at 139.8% for about a month and a half, so giving it time to adjust is'nt the issue. My FTRM is 103.1% and FTRH is 99.2%, and the car runs relatively well. As for the time to adjust....Anytime I adjust anything, the ecu adjusts within a couple of minutes of normal driving. If your at WOT or getting on it alot it will take a little longer. It has to stay in open loop for a while.
I don't think thats the problem though. I'm wondering if there is a bug in this version. Its weird that ours are stuck at the same number. Whats the chances?

 

[fwdtsi]

There has to be a bug. It just sticks there , maybe it could be MMCD do you have that?

 

[robw22]

Yep, i do. That could be the problem. Are There different versions of mmcd? If so, what do you have?

 

[theTuner]

dude i know this is offtopic but i LOVE Your valve cover, where did you get it ? seriously tho, where?

 

[fwdtsi]

No, I dont think there are diffrent versions. I have heard that there is something wrong with the fuel trims on MMCD on a thread a little while ago on here.

 

[robw22]

Originally posted by theTuner
dude i know this is offtopic but i LOVE Your valve cover, where did you get it ? seriously tho, where?

I actually made it my self. I have a couple of guys that are interested in one also. If you would like, I can add you to my list. I will be making a bunch of them in a couple of weeks. They are cnc machined aluminum and come with stainless bolts. I'll be selling them for (I think) $40 + shipping.
Let me know if your interested.

 

[Scrymerr]

I just installed a 1g MAFT1.2 in my 98 (hardwired it in) and it idles fine. I have an AFC2, AFPR, AF gauge and EGT. Pocketlogger will be here in 2 days. It was just put in no more than an hour ago, and it drives like crap unless i drive like a grandma. Once I get my logger, I will see if I am having the same problem.

--Dan

 

[kpt4321]

IMPORTANT NOTE FOR ALL 2g's:

Make sure that the baro wire is outputting the right voltage! Some ECU's have a problem where they will not get the right voltage from the MAFT (it's an ECU issue, not a MAFT issue). The output on the baro wire should be around 3.8-4.0 volts, if you are only getting 3.3 volts that will cause a problem.

 

[Scrymerr]

Originally posted by kpt4321
IMPORTANT NOTE FOR ALL 2g's:

Make sure that the baro wire is outputting the right voltage! Some ECU's have a problem where they will not get the right voltage from the MAFT (it's an ECU issue, not a MAFT issue). The output on the baro wire should be around 3.8-4.0 volts, if you are only getting 3.3 volts that will cause a problem.

And if this is the case, is there a fix?

 

[badboyr66]

Originally posted by robw22
I actually made it my self. I have a couple of guys that are interested in one also. If you would like, I can add you to my list. I will be making a bunch of them in a couple of weeks. They are cnc machined aluminum and come with stainless bolts. I'll be selling them for (I think) $40 + shipping.
Let me know if your interested.

:laugh: hey let me know when ya have some. I am intrested in getting one

 

[badboyr66]

and one of my freinds wants one too so put e down for 2

 

[Mike Licht]

The is a easy fix for the 2g problem cars. You just snip 1 resistor. Details are on the Yahoo group
Mike Licht

 

[APEXiD33a]

i have version 1.3 on my 2g , is that baro problem fixed on the 1.3 version or do i gotta go check if mines reading right , thanx Chris ,


also, just to make sure , are dipsticks down are considered off? my car has the gm maft blo through style and my car has trouble starting and then holding idle.

 

[nine5raptor]

Check yours. The problem is in the ecu's of some cars not in the eprom of the maft.

Im pretty sure down is off.

What are your fuel trims like at idle? Check for leaks.

 

[APEXiD33a]

checked my 1.3 version today , and yes i had to cut the blue resistor also. The baro signal went right up to the 4.0 and higher. Thanx for the info guys. Ill let u know how she drives tomarro.

 

[kpt4321]

Yup, down is off.

 

[fwdtsi]

Heres another weird problem I have found when I log. First, let me start of by saying that I richen idle up 10% and actually, It went down for a second but then it went right back up. It went from 139.8% to 116.2% but when I stopped it went all the way back up to 139.8%, I dont understand why is it fluctuating like this???

 

[kpt4321]

Richen it up some more, and see what happens.

A dead O2 sensor will inflate your fuel trims.

Before you decide it's that, then just richen it up some more and see where it goes. In some cases, you will need more than 20% extra fuel at idle.