ECUTEK + Stillen SC + MAP Sensor problem?
 

Hey guys. Recently had my Stillen SC installed, and tuned with ECUTek. Got it back about a week ago. Having a blast so far but have encountered one oddity.

Now I also have a small Nexus 7 tablet inside running DashCommand app which allows me to see various sensors; O2, MAF, MAP, Lambda, AFR, Timing, Fuel Trims, EGT, IAT, Coolant, and probably a couple more I can't remember.

Before the Stillen SC kit install, the MAP sensor would give me a reading. After the kit it doesn't go neg or pos, just stuck at 0.

I asked my Tuner if they knew anything about it and they said they did nothing with the MAP sensor.

So my question is what might cause this? Does ECUTek somehow disable MAP input once you check a 'Boosted' check box or something? What does the MAP sensor even affect anyway?

Tried pulling the MAP sensor plug while engine is on, and no change to idle and no error code.

Not sure what to do next. Thoughts?

Cheers,
MoulaZ

The MAP sensor on most FI builds gets turned off by the tuner, since it doesn't know what to do with positive pressure and throws a code. Most tuners disable the code. Might want to mention that to him.

Agree'd with what Chuck said, I didn't have mine turned off at fist and I got a MAP sensor CEL, I have my tuner , adjust it and never saw the light again.

Why didnt you get a juke or gtr map sensor and have your tuner enable speed density? just wondering.

I followed Seb's advice and installed the GTR MAP sensor and he tuned the car for SD while on boost. Works great.

I also installed the 4 bar GTR MAP sensor, and had SEB tune it very pleased with the results.

Honestly I'm new to boosting 370s, was a 300 TT fella for a long time. I'll have to read up on what Speed Density Tuning is.

And so it seems like it's a common thing to switch it off... kinda concerning that the Tuner himself told me he didn't touch it. =\

I also noticed they ran a cable (single core) between the 2 MAF plugs, which the Tuner mentioned they do to enable the car to idle properly. Anyone heard of this being done?

Reason behind all of this is the car got a bit of a disappointing result after the SC install, netting a 27% power increase over before the SC (to be fair, it was a pretty hot and humid day of the tune, I was told he just couldn't go past 13 degrees without pinging). It's also a little jerky when driving down low in the RPMs. Wondering if any of this is connected.

/edit

Might as well throw up the mod details:

- ECUTek
- Vortech V3 SCi Trim
- Standard Impeller
- 2.75 Pulley I believe, 9 PSI one
- Aeromotive Stealth 340LPH Pump
- Deutchwerks 600cc Injectors
- 19 Row Setrab Oil Cooler
- Motordyne CBE
- Stock Headers + Cats
- Southbend DXD 19lb Flywheel
- Southbend 'Stage 3' Full-face Organic Disc
- ZSpeed HD CSC

Appreciate the replies guys.

Cheers,
MoulaZ

Just did a logging run. Noticed a couple of more weird things. MAP Sensor is suddenly working again. Didn't do anything.

1. When going WOT, the MAF maxes out around 4400 RPM at 270g/s...

2. Occasionally the MAF/MAP readings start to fluctuate wildly, and you can feel the tiny tugs as the car tries to maintain a consistent cruise control set speed. Tends to happen more around 3-4K RPM in 4th or 3rd, not so much at lower, in 5th or 6th.

Some pictures to illustrate attached.

1. Irratic MAF + MAP Readings
2. Maxing out MAF @ 4400 RPM Freeway
3. Maxing out MAF @ 4400 RPM Standing Start
4. Example of normal readings on Freeway

Thoughts?

Cheers,
MoulaZ

Sounds like a new tuner would solve your problems.

That and a proper MAP sensor. You have spent a lot of money already so go ahead and get on board with Seb at Specialty Z and get the GTR 4 bar MAP sensor.

My supercharged Z drives like it did stock but with way more power and throttle response. Cruises like it did before all of the mods. Seb is the master of the SC Z.

.

For those of you with the upgraded MAP sensor - can you see boost through OBDII?

I'd love to go to Seb, but not sure how much he can help here given the enormous 10,000 mile pond between us. :(

And I read up and have an understanding of SD tuning now. Seems superior to MAF tuning while on boost but time consuming to retain a comfortable 'factory feel' while crusing around town off boost.

Strongly considering the GTR 4 bar MAP sensor now though. Is there anything special that needs to be done to swap over? Is it a straight fit from OEM? Plug the same?

Cheers,
MoulaZ

Couple more pictures. Couldn't send them in a PM.

2 more log shots of MAP & MAF readings at WOT in 1st/2nd Gear back BEFORE installing the SC. MAP behaves predictably... even if it is telling me I'm making about 7 PSI on a NA...? :confused:

1 log shot while cruising at about 35mph, MAP & MAF look way more predictable before the SC.

And a shot of my current SC AFR, Boost & Torque graphs (for the US bloke, add about 10-15% to get US figures, don't ask me why there is a discrepancy there between US and AUD. Also threw a graph in there showing before & after SC install.

NA = 208rwkw & 480nm > 278rwhp & 354tq (+10% = 305whp)
SC = 265rwkw & 600nm > 355rwhp & 442tq (+10% = 390whp)

Cheers,
MoulaZ

Well im in south carolina and seb is somewhere in LALA land and he has me grinning from ear to ear! If you can get an email Seb can tune it........