Is there any possibility to tune the UTEC without the MAP sensor in a revup N/A engine, and avoid that the ECU fights it back? the only solution is to install the MAP sensor?

It isn't worst in a N/A engine to use a MAP sensor instead of a MAF sensor?

Thanks for the help

 

Sure - you can tune a UTEC without a MAP sensor. From the Open Loop Fueling Menu, set the Open Loop Fueling mode = 1. This allows you to configure the tune much like a MAP tune without using the MAP Sensor. But make sure you're running Mass Air instead of Speed Density.

The beauty of enabling Open Loop Fueling, is that you can tell UTEC when to engage the Fuel/ Timing Maps from a TPS/ RPM standpoint. Since the UTEC is using it's own internal maps at this point to drive the injectors & run timing, the factory ECU can't over-ride the UTEC... Hence, the tune should remain reletively static until you tweak it some more...

I set my TPS threshold to 25%. And left the default RPM threshold at 2000 RPMs. By running the tune more from the UTEC maps (instead of letting the factory ECU intervine) the car pulls harder, more linear, and more consistantly now earlier on in the powerband...

But I was also getting some shift knock after tweaking the tune. So I was able to eliminate it by setting the Open to Closed Loop Delay from 0 to 2.

 

This is interesting information Gothchick. I was under the impression that the Open Fuelling option 1 was only usable when a MAP sensor was in the loop.

Another option is simply to pull the battery power once every few weeks to reset the ECU and eliminate ECU drift-off from the UTEC map (assuming you reset the ECU before your tune).

But I like Gothchick's explanation better. In fact, I wish the UTEC manual spent a huge chapter on Open Fuelling with NA applications.

 

I wonder if open loop fueling has any advantage when used with MAF ?

no matter what mode, UTEC will still use its own timing map which stock ECU cant override.

then, even in open loop mode, all UTEC does about fuelling is altering MAF signal going to stock ECU, so no matter what mode, stock ECU is running the injectors which UTEC cant override, but can make adjustment by fooling stock ECU.

If used with MAF, the load column is based on MAF voltage, so TPS has got nothing to do with open loop mode if used with MAF.

The only advantage of open loop mode with MAF is the ability to raise the rev limit.


That is what I got in my head, I wish to know if I am not understanding something right..

 

My understanding is that when in Open loop fuelling, the ECU is bypassed entirely for Fuel and Timing needs. Timing and Fuel are controlled by the UTEC. For Fuel, the UTEC uses MAP data to drive the programmed injector pulse width map. Since offsets are no longer used then the ECU can be bypassed in this regard. I believe this results in the ECU being unable to tune-out the maps.

I'm in the same boat as you though.. I've never worked with injector pulse maps so I cannot recall right now if this is exactly the way this works.

 

that is correct if you are using MAP sensor, but if you are using MAF, it still uses offset method to control A/F..

 

just tried the open loop mode, revved upto 7000rpm without any problem..

now, one thing i found is that the tune I did to my a/f became way off. Looks like UTEC has a built in fuelmap that we cannot see, and in open loop mode its offsetting from that map hidden in UTEC. if this is true, this would mean that we can actually fully bypass the stock ecu fuel map. more test to come.

 

alright.. just came back from another run. and yes, looks like the UTEC has its own fuel map and in open loop mode its running that map instead.

 

I think that Bleunetizen is right and with the MAF sensor the UTEC can't take full control, it will only modify the input signal from the MAF to the UTEC and make it think that more or less air is going throught the intake, making the ECU to use a different value from his tables...but learning mode of the ECU will correct this in a time, thinking that the MAF is a little dirty or something like that.

So, the only way to avoid this seams to be unsing a MAP sensor that has less resolution than a MAF and not designed to work in vacum

 

Wrong, the UTEC can run open loop fueling in two different ways. You can use MAF as load reference or Map as load reference (turbo application). For NA cars the best way to do it is the MAF as load reference. This gives you the ability to have complete control over fueling without the factory ecu variances. The default settings have Open Loop Fueling enabled with MAF as load.

I'll be back to answer some more questions after i go to the dentist.

 

Jeramaine - did you get my email that I sent on 18th last month? I am getting check engine light with UTEC and I wish to know if I have to send it back to you and get a replacement.. I live outside US and hope its something that can be fixed easily

 

Thanks very muchu for your aclarations BlackTuner, I'm receiving my UTEC this week and I was a little bit dissapointed with that problem

 

i had my car tuned about a year ago with the utec. i noticed over time the car ran differently and not as good as when i had it tuned. i just recently reset my battery for other reasons, but the car seemed to run better. i don't know if this is directly related to the reset...but have never really got an answer as to why your tune would be different from 1 day to the next?

 

Were you running open loop fueling? If not, then you have your answer...

If so, then, well that shouldn't be possible.

 

Or at the very least, he as another issue afoot. :-)

Thanks BT for the clarification. Looking forward to the rest of your reply. The manual doesn't cover MAF open-fuel tuning too much. Although it has been months since I've read it. :-)

 

have any of you guys w/ the 06 revup been able to raise the rev-limiter?

 

I think that by the moment is not possible, but it would be interesting to know if it will be possible in the near future or not

 

BT BT BT BT..

Anxiously awaiting the rest of your reply. :-)

 

It would be nice to have rev limiter at 7500 at my revup!!!!! that would turn it into a ultra-revup!!! LOL

 

Is your bottom end stock?

Is it safe to turn a stock lower end up to 7500 RPM?