---===The Official MAFT-Pro Thread===---

[3000vr4tt]

when it first starts up its lean then after liek 15-30mins an a couple of revs itll drop down to liek 14.7-15.5 and will go back to normal vac an sound normal

[Rogue_Ant]

What does your low-trim say?


-Rogue

[mightymoose]

Im having an issue with my 92 VR4 running in SD mode. Essentially car has been running great up until I had a misfire issue(turned out to be a little with the tune and the TPS was shot)

now what is going on is this: when in decel mode and letting of the gas pedal im either reading very rich or right at 14.1-15.8 AFR. There are no intake/exhaust leaks, everything else is doing fine, new fuel filter, checked injectors, etc, etc.. AFR will read 22.2 for about 2 secs then drop into the 11's-13's
Only thing I have changed is adj. the BOV and installed the pre-turbo dejon intake pipes, but this was happening prior to install.

I wonder if my BOV is sticking and leaking. or perhaps an 02 sensor on its way out?(only about 14k miles on the 02 sensors though)

any thoughts on this, what to look for, etc..

thanks in advance
James G

[Rogue_Ant]

Sounds like your TPS needs adjustment.


-Rogue

[TurboBob]

record a log and post it.

Bob

[mightymoose]

forgot to mention I installed a new TPS sensor and installed it correctly, ill post a log up later on if I get the chance,im leaning more toward the bov sticking, its old and get lots of surge from time to time

[mightymoose]

well I did 2 things: adj. the BOV again and double checked TPS setting. the BOV more than anything was/is the culprit..lots of surge, leaking badly,etc car now leans out while in decel. however, it delays for a few seconds and runs very rich. Also I suspect a faulty TPS connection at the MAFT-pro unit itself.. don't have my papers/notes with me at the moment, could someone please tell me which wire is the TPS for the maft-pro.

thanks
James G

[UCSB VR4]

Hey guys... my car has been running very well lately, I've finally got a great "daily driver" tune going with good gas mileage and also good driveability.

I'm now venturing into the WOT tuning stages... I just made my first WOT run while logging and came up with some interesting results. I wanted to get a second opinion on what changes I should make to my boost control settings in order remedy the problem.

I'll start by posting my boost settings on the maft pro:

Boost control TPS Spool 2.00
Boost control RPM Spool 2688 RPM
Boost control TPS Start 3.70 Volts
Boost control PSI Start 12.40 PSI
Boost control DC% Start 25.20 Percent
Boost control PSI Set 15.00 PSI
Boost Control Gain 0.00
Boost Control Max RPM 8160.00

Note: Gain intentionally set to 0.00 for now, wanted to get a ballpark setting before enabling this feature.

When I made my WOT run, the car was building boost very nicely up until I reached my "PSI Start" setting (i.e. 12.4 PSI) when suddenly the duty cycle dropped from 99.6 (spool mode / solenoid full on) to ~25.x (start mode). When I reached this point, the boost suddenly peaked at 13 PSI and then immediately dropped down to 6.x PSI and stayed there from 4500 RPM - redline (i.e. the remainder of the WOT pass).

With that said, obviously my target PSI is 15, and the sudden drop to 6.x PSI is not desired. My question is whether I should increase my duty cycle, or should I increase my "PSI Start" setting to some higher value? I'm pretty sure I just need to increase my duty cycle to ~60%-ish.

Technically the unit is working properly, I just would like some advice on how to correctly modify my settings before moving forward.

I've also attached my log (wot.csv). You can easily see the issue in there.

Thanks in advance for the help.

- Jeff

[Rogue_Ant]

Originally Posted by mightymoose

well I did 2 things: adj. the BOV again and double checked TPS setting. the BOV more than anything was/is the culprit..lots of surge, leaking badly,etc car now leans out while in decel. however, it delays for a few seconds and runs very rich. Also I suspect a faulty TPS connection at the MAFT-pro unit itself.. don't have my papers/notes with me at the moment, could someone please tell me which wire is the TPS for the maft-pro.

thanks
James G

Are you using the Drop-Throttle Limiting stuff in the T-Pro? If so, they need to be adjusted to your new TPS.
The TPS wire for the T-Pro is the Blue wire on the 10pin connector.


-Rogue

[Rogue_Ant]

Originally Posted by UCSB VR4

I'll start by posting my boost settings on the maft pro:

Boost control TPS Spool 2.00
Boost control RPM Spool 2688 RPM
Boost control TPS Start 3.70 Volts
Boost control PSI Start 12.40 PSI
Boost control DC% Start 25.20 Percent
Boost control PSI Set 15.00 PSI
Boost Control Gain 0.00
Boost Control Max RPM 8160.00

Note: Gain intentionally set to 0.00 for now, wanted to get a ballpark setting before enabling this feature.

- Jeff

Gain increases/decreases the duty-cycle, to be able to accurately hold the desired boost level.
Your settings look alright, I would increase the DC% to 50 or so, and set your Gain to 6 (if you have boost oscillation issues, then you can lower the number).


-Rogue