Hi everybody,

I have an ECUTEC reflash on my STi. Only mod was perrin inlet tube.
Meanwhile, I purchased a used UTEC for the benefit of multiple maps planning to use it on top of the ECUTEC flash.

I now have a stock catless TBE. So I decided to have the car retuned via ECUTEC. My tuner was amzed that my car only made 12.4psi. He replaced the "pill" but all he was able to do was 12.8 with the stock solenoid at 88%.
So the shop start looking around and connected a boost gauge (I know I know I should get one) and was able to see that the car boosts about 17psi. Car feels fine and pulls hard. But the ECU signal (via ECUTEC delta dash I believe) still says the car is doing 12.8psi. So I am kind of buffled. I have the UTEC with a remote map switcher installed. the switch is reading 0. So in my eyes it should be pretty much a passthrough. Is that correct? I am sure I put the switch on the UTEC itself on map 0 so it should work with the remote switch.

Any ideas why the car would really be doing 17psi but via the ECUTEC deltadash shows 12.8 psi? Am I missing something here?
Any input will be appreciated.

Regards

Nick

if the utec is connected, and the fcd is on, the delta dash wont see the right boost...

...because then the ecu wont see the right boost, and wont throw a CEL if the boost is too high.

^^^^^^^^^^^^^^^^^^^^^^^^

Check UTEC logs.

I just ran into this issue with Cobb ST and the Utec. Even on map0 the utec loads the MAP signal line. The fix I did was to cut the wire for the MAP signal on the input of the stock ECU and solder it to the MAP input of the UTEC. This was sugested by Pete from TXS.

TMS

I just ran into this issue with Cobb ST and the Utec. Even on map0 the utec loads the MAP signal line. The fix I did was to cut the wire for the MAP signal on the input of the stock ECU and solder it to the MAP input of the UTEC. This was sugested by Pete from TXS.

TMS

The FCD is not on. As far as I know when I installed it.
It loads the MAP line hmm.... I think this is the problem.
Now spare me here, when we say it modifies the MAP line, I have no clue what does that do? Modifies the boost, modifies the timing, modifies the fuel? Modifies something else?

I am not really willing to splice the MAP line on the ECU. :(

So let me ask this. If I take the UTEC off. Tune the car via ECUTEC. Then I put the UTEC back on. Does it affect the tuned stock ECU (via ECUTEC)?

Any input appreciated.

Regards

Nick

Even though I had the FCD off the stock ecu was seeing 10 psi when the Utec and my boost gauge would show 15psi so I was not near the MAP clamp of the Utec. The MAP sensor voltage was changed by the utec. When my Cobb would see lowwer boost it would run more knock corection. As soon as I jumped the MAP signal around the Utec and the Stock ECU saw the corect boost my knock corection dropped ~4 points. So yes I would say that it effects the tune.

TMS

Even though I had the FCD off the stock ecu was seeing 10 psi when the Utec and my boost gauge would show 15psi so I was not near the MAP clamp of the Utec. The MAP sensor voltage was changed by the utec. When my Cobb would see lowwer boost it would run more knock corection. As soon as I jumped the MAP signal around the Utec and the Stock ECU saw the corect boost my knock corection dropped ~4 points. So yes I would say that it effects the tune.

TMS

Would you say in conclusion that before you jump the MAP signal it also pulled timing?(at the upper RPM) and as a result loosing substantial power (like 15-20whp or more)?


Thanks for the input.

Nick

Would you say in conclusion that before you jump the MAP signal it also pulled timing?(at the upper RPM) and as a result loosing substantial power (like 15-20whp or more)?


Thanks for the input.

Nick

The reflash was adding timing based on a lowwer psi reading/lowwer load. You might not even get the boost the reflash is set to on map0. Time for a boost gaugeand check your logs to see what the boost does. The timing did not go far enough for det running sunoco 93. I don't know how the ECUtec was tuned on your car. Post up some Utec logs and a log from the stock ECU using deltadash, tari1 or SM3. By comparing the two you can determine if if it is the tuning or the stock ECU doing wierd things because of the low MAP input.
Or just try taking out the Utec and resetting the ecu. If your boost comes back then it is the low MAP caused by the Utec. Personally I like have the MAP jumpered arround the Utec that way map0 is my reflash in control of boost accurately. You don't have to cut the stock harness to do it. You have to cut the harness comming off the Utec and just strip back some insulation on the stock harness.

TMS

if the utec is connected, and the fcd is on, the delta dash wont see the right boost...

...because then the ecu wont see the right boost, and wont throw a CEL if the boost is too high.
THis is ur answer. If your tuner doesn't know this I would get a new one...

I just ran into this issue with Cobb ST and the Utec. Even on map0 the utec loads the MAP signal line. The fix I did was to cut the wire for the MAP signal on the input of the stock ECU and solder it to the MAP input of the UTEC. This was sugested by Pete from TXS.

TMS

The UTEC when installed has all the ECU wiring harnesses plugged straight into it. The ECU is ONLY connected to the UTEC, not the car. Sure that's how Pete stated it? It doesn't make any sense, unless there is some extra external MAP sensor input on the UTEC that I'm not aware of.

Anyway, I'm waiting to see a UTEC log. I wouldn't think in stock mode (map 0) the UTEC would limit the MAP signal being sent to the stock ECU. It really shouldn't. This is the relevent part to this whole mess, soldering wires or not, you shouldn't have to solder a wire for stock mode to send correct signals to the stock ECU.

Is the selector on the UTEC box itself set to zero? Are you using a remote map selector?

THis is ur answer. If your tuner doesn't know this I would get a new one...


The FCD is not not on.

The UTEC when installed has all the ECU wiring harnesses plugged straight into it. The ECU is ONLY connected to the UTEC, not the car. Sure that's how Pete stated it? It doesn't make any sense, unless there is some extra external MAP sensor input on the UTEC that I'm not aware of.

Anyway, I'm waiting to see a UTEC log. I wouldn't think in stock mode (map 0) the UTEC would limit the MAP signal being sent to the stock ECU. It really shouldn't. This is the relevent part to this whole mess, soldering wires or not, you shouldn't have to solder a wire for stock mode to send correct signals to the stock ECU.

Is the selector on the UTEC box itself set to zero? Are you using a remote map selector?


I totally agree. I am a bit dissapointed that I have to solder/strip wires to get map 0 to be a true passthrough. I am in map 0 and the UTEC itself is set to 0 and I do have the remote selector. I do not have my laptop handy to get a few pulls. But I will do it tomorrow when I borrow a laptop from work.

Cheers

Nick

The FCD is not not on.
yeah, like TMS said, even if the FCD is off, it still doesnt report back accurate boost.

and likewise, the suggestion TMS offered up will work. someone else also reported splitting the wire, one going to the utec and one going to the stock ecu and said it worked fine. this is what i would do, personally. (and kinda funny, because i am running a street tuner underneath a utec....i just never use the ST. lol)

Anyway, I'm waiting to see a UTEC log. I wouldn't think in stock mode (map 0) the UTEC would limit the MAP signal being sent to the stock ECU. It really shouldn't. This is the relevent part to this whole mess, soldering wires or not, you shouldn't have to solder a wire for stock mode to send correct signals to the stock ECU.

Is the selector on the UTEC box itself set to zero? Are you using a remote map selector?

Everthing you are saying is true. But it just does not work that way IRL. The FCD is just a voltage clamp it will not let the stock ECU "see" above a certian voltage. The thing is the Utec also messes with the voltage before it reaches the level the clamp would come into play. Sorry can't help you with a log as I have all ready done the fix.


The UTEC when installed has all the ECU wiring harnesses plugged straight into it. The ECU is ONLY connected to the UTEC, not the car. Sure that's how Pete stated it? It doesn't make any sense, unless there is some extra external MAP sensor input on the UTEC that I'm not aware of.

You have to jump the MAP signal around the Utec and have the MAP signal directly conected to both the Utec and stock ECU. The Utec has inputs the stock harness plugs into and outputs that run through the harness to the stock ECU. You have to cut the output of the Utec/input of stock ECU and solder that to the stock harness. Effectively bypassing the Utec. This only works if you can set the over boost fuel cut in the stock ECU.

TMS

As long as a UTEC is plugged in, the MAP signal is *always* modified.

It doesn't matter how the FCD is set.
It doesn't matter if you are on map "0".

The UTEC *always* modifies the MAP signal before it gets to the ECU.

Just a reminder the ECU use the MAP signal for boost control and boost cut, not much more.

The ECU is MAF load based!!!

The timing and fueling that the ECU runs is based on MAF not MAP.....

So is the issue here that you want to use the ECU boost control in pass through mode and the UTEC is masking the MAP signal?

I can't help. I use the ECU for a low boost (14 psi) map and the UTEC for everything else.

Thanks everybody. It seems that UTEC is not designed to work in conjunction with tuning the ECU as well as running a tuned UTEC on top of that. I am guessing I either have to bypass the MAP wire. Or tune via the UTEC. Or offcourse get rid of the UTEC and get the AP.

My initial reason for getting a UTEC was simple.

Have my car ECUTEC'ed for TBE/injectors/FP20G on 91 CA octane.(run 18-20psi max)
Create 3 maps via the UTEC on top of that.
1)SMC alcohol injection using 100% water
2)SMC alcohol injection using 50% alkohol 50% water
3)SMC alcohol injectionusing 100% alcohol.

Switch via the remote map switcher according to what I run in the car.

It seems that I should have asked the above questions before I purchased the UTEC. :( Live and learn.

I already have the ECUTEC license but it seems the plug anf play solution for me will be to dump the UTEC (make a few dollars selling it). Dump the ECUTEC (bye bye $6xx license since it is not transferable or saleable). Get an AP. (6xx) dollars. Shoot I should have almost gotten me a Hydra and be done. :)

Cheers

Nick