I've been running a used M-tune setup for a couple weeks now and have a couple little quirks I'd like to resolve. I do not think it is M-tune, I think they are some minor(hopefully) issues with my car.

The first thing it's doing is a weird 'blip' when coming down from rpm's. It does this when I hold at higher rpm's or lower rpm's then let off the gas - the rpm's come down, then a 'blip' like I hit the gas pedal (but I'm not), then a bit of hanging at ~1500 rpm's before settling down to idle at ~840 rpm's (via Rogue's logger). I'm thinking the bit of hanging is a normal emissions thing, but the 'blip' is something I don't think should be there.

The other thing it's doing is at 'tip in' I believe (I think I'm using the term correctly). If I'm cruising at slow speed/light load around town and then give it a bit more gas it will stumble or start to jerk back/forth sometimes. It also does this if, say I'm cruising slow speed/light load, have to let off a bit to slow slightly, then give a bit more to speed up slightly. I set the TPS switch and hear the click just as I start to apply pressure, so I believe I have it adjusted correctly. Could this be a sign of a bad TPS?

One other thing to note is that it doesn't idle completely stable - the rmp's move between 840~900 and I see the afr's move along with it too. It doesn't vary wildly, but it's there. I saw the same thing when I was running A-tune and the stock airbox setup. I've checked for vacuum leaks and all looks pretty good (small leak at the throttle body is all that's left).

Any ideas/suggestions?

 

Have you reset the via the standard clarks-garage method?

If not, then do that.

 

I did, but I checked it again after making sure I was up to temp and it wasn't quite on so I re-adjusted. It's definitely better as far as the tip in. I still have the blip when I let off the gas (and then it hangs for a bit before returning to idle) - that's not normal, is it?

I do have to say, overall it's running very, very nice. Completely docile and quiet cruising around until you get on it. One other thing I was going to ask - I didn't touch the boost controller (black ****) and went from A-tune w/stock airbox setup to the M-tune and the boost went from 15psi to 17+psi - is that normal too?

 

These are almost to the T the drivability issues I'm having with my recent M-tune. I also skipped the idle reset because it seemed to settle in to a nice 900 rpm idle. I'll have to do the reset and see if the tip in cleans up. I notice it mostly if I'm on the highway and boost builds to 5 psi and then I have to lift and reapply throttle. Yours is all sorted now mountain man?

 

The little "burp" when the revs come back down is normal. That's the injectors turning back on. If you have the tuner, you can adjust where that happens. I set mine to 3000rpm or so, I think the default is 1600 rpm?

I can't say I've experienced the tip-in issue you describe though.

 

Auto_werks - still not 100%. I'll have to try lifting/reapplying when in boost. I notice the jerking when I'm cruising light load and have to lift then re-apply (i.e. normal city driving in traffic).

Thanks for the feedback on the blip Jim. I just bought the tuner, so will look into it.

I'm thinking the tip in may be something to do with my throttlebody or the TPS - those are about the only thing I haven't touched on the car yet (did adjust the idle switch properly, but that's it).

 

Under global idle, then "fuel injection cut - coasting". I set the last two cells at 3000rpm. Its less noticeable up there.

As for the tip in issue, a vacuum leak could cause what you're describing.

 

Try unpluging the O2 sensor and see what happens. That was the issue with me once.

 

I keep trouble shooting mine, and the the more small issues I find the worse it runs. Fixed a few small vacuum leaks, put the "correct" plugs in, and now it runs like a complete bucket of crap. I ordered a wideband for the car so I'm not exactly sure where I am, I wasnt to worried because I spent the first couple hundred miles running a new turbo and rod bearings easy. I can say the plugs are completely black, and the gas mileage was terrible! These kits are designed to run with the 3 bar fuel regulator are they not? None of the instructions mention it on lindseys site, or rogue tuning, but on the LR order page it gives you the option to add one To your mtune order, so I assumed that was the right thing to do.

I have not been bothering lindsey, and trying not to bother Joshua to much, so I have nothing to complain about on the customer service side, just trying to figure this thing out on my own / with community support.
thanks!

 

Yes, it is designed for a 3bar FPR...

If your plugs are black - then something is up. The car should not be that rich...

Have you verified the MAP sensor is working properly?
Coolant temp?
What are the DIP switches set to?
Coding plug?

 

I believe the map sensor is working, is there a quick check for it? At one point while I was working wi th the vacuum lines I disconnected it and the car would no longer idle. Is there a quick test for this?

The dip switches are set for pump gas and valet which I believe was middle 2 hi, no coding plug. It was originally set all 4 low for race and pump before I learned to change them and the car didn't run appreciably different.

I reset the idle per clarks garage and that seemed to have no effect.

I checked to make sure the MAF was getting 12 v and i checked the operation of the TPS and switch per clarks garage.

I used to have the boost set for 10psi and it ran pretty good, bumped it up to 15 psi tonight with a tank of better gas and it just falls on its face

 

I see the map sensor test on your site. I'll run out and do it now

 

Go back to all switches to the 'off' position. (until we get it sorted)

Probably best to swap in a fresh set of plugs.

The MAP sensor: With the ignition on, measure the voltage on the red wire to ground. You should see +5volts. Now measure the voltage on the green wire. This should read ~1.6 volts (this will vary slightly depending on altitude). Then, start the car, and measure the voltage on the green wire again. This time it should be < 1.0 volts.