going lean

[ZEDRATED]

hi everyone again, so I have my car starting and running pretty good except for one major problem. At about half throttle, mostly noticeable in 3rd and 4th gear my car is going lean, maxing out the afr gauge and hesitating and it was setting a high maf code 33 until I changed the threshold to go all the way max. I don't believe the maf has a problem as this car never set a code 33 before with my stock prom. I took a log of it doing it, you can see the tps go to about 1.8v-2.2 volts and this is where the afr is going max lean and hesitating. Attached is the bin file and my log. Can anyone help?

[dave w]

I would make small adjustments to MAF Tables. The More Air (Grams/SEc) going thru the MAF the higher the voltage. Table #1 is normally for idle. Table #6 is normally WOT. Increasing the Grams / Sec number for a specific MAF voltage increases the fuel from the injectors (richer) for that specific MAF voltage.

The bad news ... the data log DOES NOT record MAF voltages corresponding with the Grams/Sec!

Its 100% trial and error to figure out what MAF table to adjust!

dave w

[ZEDRATED]

I believe my tuner guy gave me a definition file for $32B that actually showed MAF voltage. Maybe I'll take a look and see. Why would my computer be setting a MAF high code 33 thought????

[dave w]

The attached screen shot in my first post is from $6E, I think $32B is similar.

I've read that the TPS might be cause for code 33. I've also read the MAF relays can cause code 33. I would check the wiring / connector to the MAF.

dave w

[ZEDRATED]

But why no code 33 with the factory prom but with the bin file I posted it sets the code and this is right after the car is going lean at half throttle??? Would a high MAF code cause the car to lean?

[dave w]

I can't explain why the modified .bin file is setting code 33. I might be able to figure something out, if you can post the original .bin file.

dave w

[ZEDRATED]

I'll post it tonight. Thanks.

[ZEDRATED]

here is the stock prom bin that we built off of:

[dave w]

I did a compare in TunerPro, 377 difference. It could be some of the changes are causing the lean condition.

I am NOT a TPI MAF specialist / expert! I don't have anywhere near the experience with the TPI MAF systems, like I do with the TPI MAP system.

I find some of the differences interesting, which I've made a screen shot of.

Are you using stock / factory TPI injectors? The Injector PW Correction vs. Battery Voltage show changes. Very accurate measurements are needed when changing the Injector PW Correction vs. Battery Voltage settings.

The MAF table changes look odd to me with negative numbers, but like I said I'm not a MAF expert. One train of thought I have; an engine that has improvements to the Intake / Exhaust system would likely have more air flow in all MAF voltages?

dave w

[ZEDRATED]

Oh god no lol. This car is far from stock.
24lb Bosch 3's injectors, I got the offset values from John at FIC.
ZZ4 350 with the GM hot cam.
58mm BBK throttle body, headers, tpis miniram intake.

[ZEDRATED]

The MAF table changes look odd to me with negative numbers, but like I said I'm not a MAF expert. One train of thought I have; an engine that has improvements to the Intake / Exhaust system would likely have more air flow in all MAF voltages?

dave w[/QUOTE]

Maybe possible that you are using the wrong definition file?

[ZEDRATED]

Now let's say I want to add more fuel in tables 2,3,4, and 5 by how much should I increase?
Don't forget that at this certain spot where I go half throttle the AFR gauge is going max lean and the car is bogging out.
I have a definition file that showed the MAF ranging from 89-108 when the TPS was from 1.8-2.10 where I was getting this lean condition.

[dave w]

Maybe possible that you are using the wrong definition file?

see attached

dave w

[ZEDRATED]

see attached

dave w

it should be ok but u have something wrong as those MAF values are not right.

[dave w]

The compare screen shot is the difference from the current .bin to the original .bin.

Anyway, I went searching Thridgen.org to see if the MAF voltages could be set up in the data log; here is what I found: http://www.thirdgen.org/techboard/di...-tunerpro.html

dave w