o2 removed, ecu still showing vf

[3p141592654]

I have just begun to dig into the GTE code. It will be a while before I can answer your question. AS far as THW goes, its treated exactly the same as THA, there is a 10 bit ADC that converts the sensor voltage to a digital number. It checks if input range is valid (76 mv < THW < 4.73V). If out of range defaults to 80C.

If in range, it then does a piecewise curve fit and interpolation to linearize the sensor output and averages to the previous reading. That sensor value is then used all over the place to adjust calculations.

Interestingly, during cranking the THW sensor is read very rapidly (THM->AFM->THM->TPS) over an over. Once the engine starts, it reads THW only once for every approx 127 TPS and AFM conversions.

We surmise that during starting the coolant temperature can vary greatly as the sitting engine develops hot and cold areas that rapidly change once the coolant starts to flow again, so rapid readings are needed to get an accurate temp reading.

Anyway, I'll post up more when I know more!

 

[CRE]

Well, I hooked up the Pro's Aux In #2 to the THW line. The MAFT Pro and ECU do not get along at start up... while cranking the MAFT Pro lost power (it's wired to power from both Acc and Ign and they're isolated with diodes, so this shouldn't have happened) and the car had a rough time cranking. I can connect the monitor line after starting without any trouble though. Any thoughts on this?

So I connected it all and went for a drive... Unfortunately, my laptop battery died halfway through the drive and the log got corrupted. Bob, any chance you can get data from this log? If not it's no big deal, I can make another tomorrow.

 

[grimreaper]

never resolved this. other issues kind of got in the way. Very interested in what you guys figure out so keep posting!

 

[CRE]

Hey Bob, did you get the log I emailed you a couple days ago? It was the day after my last post actually.

 

[mk3tattoos]

i would love to learn more about this, lets hear some more info!

 

[grimreaper]

Nothing else going on with the car right now sooo I'm going to try a tccs reset and forced open loop via o2 signal wire removal. Ill leave the heater circuit intact to save the sensor and incase i need to hook it back up when on the go...

I'm doubting the outcome but didn't do much testing last time. *crosses fingers*

 

[kisedcd]

Yesterday I enabled PT Tracking and forced the ECU into open loop. Cold start, the car responded well but needed some tweeking. Stopped to get gas, started the engine, ran like crap and the VF signal was between 3 and 3.5.

Got home and found this thread.

Seems as though the ECU is going into a limp home mode due to missing the O2 signal in a warm start condition.

I installed a momentary switch like what was discribed which worked, wondering what the posibility is of a fix in the Pro.

PT Tracking at this point seems to be a great option. It's getting better as I learn more tuning it.

Keep up the good work identifying and working out particulars in the system.

 

[seacombe2379]

Hey kisedcd did you have any joy with the open loop

Seems if you do a warm start the tccs screws itself

Im in the prosses of fitting the lil black box of joy with all the options and want to be able to get the ptt working correctly.

 

[kisedcd]

Wow, I can't believe that it has been this long since I visited this thread.

To answer your question though, closed loop seemed to work pretty well. I had issues of an unstable idle at the same time watching AFR numbers going rich then lean, just oscilating up and down.

I enabled PT tracking for troubleshooting purposes and found it to work pretty well though it didn't help with the problem I was chasing.

Today, I'm accually looking at disabling PTT, one big reason is the dislike of having to push a button for 10 seconds at a warm start up and having to mess with a trouble codes all the time. I like to apply the KISS (keep it simple stupid) approach to as many things as I can. The button pushing just isint doing it for me.

Good luck with your install, by now it's probably all hooked up and running.:icon_bigg

 

[grimreaper]

I wouldnt bother with ptt, the tccs obviously has other fail safe measure to do what it feels is needed. Try it though and see if your set on it. Just dont weld the o2 sensor fitting shut.
I think once 3pxxxx gets the tccs daughter boards up and working, we will be able to force open loop internally. although the maft pro or any other piggy back will be useless as well

 

[seacombe2379]

kisedc - I am running it now but still have the stock O2 sensor in place getting good afr's right across the range and a nice lean burn on highway run as well so something is either working or not working??

Grim - nopw i wouldnt commit myself that far untill i was 110% sure it was gonna work correctly without having to revert back

sorry if it dont make sense im still drunk from my date with Smirnoff last nite (i really should lay off it now)

 

[kisedcd]

seacombe2379 If you still have the narrowband hooked up your not in open loop. The clean AFR's you are seeing are being controlled by the TCCS. Leave the narrowband installed and connected so that the heater circuit is still connected but remove the signal wire so that the TCCS will go into open loop. Now activate PT tracking and your on your way. Dont forget the warm start switch........you'll need it.

I got off the fence and went back to closed loop. I had left the narrowband installed yet pulled the signal wire, all I did was reattach that wire and we are back.

I kind of forgot how well the TCCS manages the engine. The car has been more of a joy driving, even at 307rwhp @ 11 psi, there is much more room to grow.
Still have an issue at idle, engine warm, trans. in park, foot off break, AFR's go lean. Oscilates up and down but seems to smooth out some. Vacuum leaks have been ruled out using propane (I did find a large leak which was causing the engine to die under heavy vac).
At the moment working on reinstalling the 440 injectors to varify if it may be an injector issue.

Bottom line - homie not playing PTTing any more.:icon_bigg

 

[JimR]

I've been thinking of going back for a little while now too.... it's just a pain to keep resetting the 25 and 26 codes, and the afterstart compensation just doesn't do the trick as well as the ECU can. I think I'll use the Enhanced TPS function instead to deal with the 3500rpm lean spot.

 

[grimreaper]

enhanced tps will leave a stored code 41 (tps code) since the tccs boots faster then the m-pro. I didnt even realize i had the code until I checked them before tear down! Didnt notice anything when driving but loved the fact that I had full contorl over af ratios as soon as I went into positive boost.

I seem to rembemer a few guys getting the pro to boot before the ecu. I still have plans to get mine setup this way when I get to it. Should take care of any codes at that point..

 

[kisedcd]

There is the posted mod to have the Pro powered up prior to the TCCS, I accomplished that at the initial intall of the Pro. There are several different ways of accomplishing that but I stuck with what I thought was the easiest given I had the componants which were two diodes feeding power from ACCY PWR wire and I believe the crank or start PWR wire.

I havent' had any issues wiring it this way, but would advise fusing each power wire to properly protect each curcuit.