maft GEN2 tuning questions

[TurboStreetCar]

ok i got my 3.5 inch maf, i set it to LS1 aluminum and it wasnt the right scaling and i found the closest match was on 3.5 inch LT1. i still had to play with the maf scale adjustment to get it to make the VF 3 volts but it was alot better then the 3 inch maf i had. i got her all tuned up and the only problem im having now is that idle tip in problem.

also my zeitronix wideband isnt displaying right threw the GEN2. its displaying 18:1 when its at 14:7 at idle. te voltage into the maft its 3 volts. i looked up the air fuel voltage scale on zeitronix;s website and 3 volts does equal 18:1 but its wierd that the gen2 is revieving a half volt more then the zeitronix should be putting out. im gona look into the wiring to see if i can figure it out.

any information on the off idle tip in? i tried adding about 10% at 400 on teh low tune and it helped a little bit but its still there.

Thanks,
Dan

 

[TurboStreetCar]

Another question i had is, can i get a GM intake air temp sender and use it so it will compensate for climate changes like the stock setup? yesterday it got cold (went from like high 60' mid 70's to like high 40's mid 50's at night) and my a/f's went from mid to high 11's to mid 12's and i was wondering if i could use the GM intake air temp to automaticly compensate for the temp change.

 

[drjonez]

no need. the hotwire sensor already accounts for temp.

 

[TurboStreetCar]

had another thought about the intake air temp, i figured since it was about that temp at the time i would just put a resistor in between the THA and E2 so the computer would have a intake air temp reading, i used a 3.2k ohm resistor witch would give it just under 68 degreese acording to the TSRM.

should i put in for a diffrent temprature? could that be the reason i have to tune the maf scaling on the gen2? or dies putting the resistor take the computer correction out of the equation, then the maf accounts for temprature?

sorry about all the questions, theres just so much goin on with this its hard to keep track lol.

Thanks,
Dan

 

[drjonez]

...or dies putting the resistor take the computer correction out of the equation, then the maf accounts for temprature?

exactly correct. the way the hotwire MAF works allows it to compensate for intake temp/humidity.

 

[TurboStreetCar]

ok so i got everything tunes out except the tip in problem, i tried addding 10% fuel at 400rpm in the low table, and 5% at 800rpm and it still hasnt helped much. any ideas on this one?

 

[turbobob]

a couple ideas.

On my dodgeabishi (Stealth) the ECU has a couple things it does if the idle is outta whack, including large changes to its idle fueling.... But off idle its back to business as usual.

It could be that your ECU is making a large correction for idle, but the minute you step off idle your main tune is off.

However, some things to try.

When you step in, the load moves almost instantly to the mid range for a moment. So add some fuel in the Mid page, 400, 800, etc.

You can also add fuel based on the flow, using the corresponding page.

Describe any PCV mods, or BOV's you may have.

Bob

 

[turbobob]

its odd that the 3.5" Aluminum setting was off, we use that sensor a lot and it should be very close. How is it installed? What airfilter, etc.....

Bob

 

[TurboStreetCar]

actually i just checked today and i am using the LS1 aLuminum setting, sry about that, but i do have alot of correction in the MAF scaling. im running a stock intercooler steup with HKS drop in intercooler and the 3.5 inch maf is in the stock accordian hose, the PCV is hooked up as follows, a hose comes out of the exhaust side cover, into the horizontal side of a t-fitting, the downward leg of the t fitting goes into the intake side cover, the other horizontal leg goes to my catchcan,(cambelhausfeld air compressor filter) and outlet of that goes back across the front of teh covers and into the stock acordian hose,.

my blow off valve is an ebay special, nothing fancy. and the air filter i got from pepboys its teh blue one that says power adder on it lol. i needed a filter and they had one.

now that u mention the idle correction, the compuer does some funny stuff at idle. ill let it idle for a few seconds and it will be runing around 15.3 to 15.8 air fuels and the VF signal will be low at 1.25 volts. its pulling fuel and running lean. ill add fuel to get it to go back to where it should be and it just keeps correcting for 15.3 to 15.8. ill make a log of it tomarro, or ill check in a few andsee if i can find a log of it.

also im using the TPS to calculate load so it doesnt spike to the mid tabel, i did try adding fuel in the low range tabel but then when im letting off it would run rich and sputter. im going to mess with the idle corrections and see if i can get some better response out of it. whatu said about idel correcting bieng way off but main tune bieng on causing the hesitation makes alot of sence, ill chekc into it tomarro.

Thanks for the help guys,
Dan

P.S if u dont have the money for the maft pro, and u want the tuneability and advantages of a GM maf i highly recomend the GEN2, works sick.