EPS with no Long or Short Fuel Trims

Valhalla

Valhalla

Legendary Member
Joined
4 April 2011
Messages
2,468
Location
Fountain Hills, AZ
OK, so after I suffered through this, http://www.nsxprime.com/forum/showthread.php?t=152121 , I figured I was home free.

I bolt on the turbos, install the gauges and base map and I try to pull up my fuel trims both short and long on my scanner. I get nothing, nada, bumpkis, ziltch. OK, so maybe I didn't spend enough on this scanner. No worries, Bisi has one and the car will get tuned this morning at 10:30. So I carefully drive to Bisimoto Engineering to get it tuned. Do you know how hard it is to drive an NSX under 3k rpm? It is damn near impossible but I did it.

If you have not met Bisi before, you are in for a treat. Couldn't be nicer, more humble and polite. A true gentleman. So we hook the car up to the dyno, get the computers up, scanner on and Bisi goes to work. After half an hour of playing with fuel tables he starts to make phone calls to AEM and then to Jon Martin. Seems he is not getting any trim readings either. Absolutely zero readings like they don't even exist. We unplug the F/IC and plug the harness back into the ECU, just like stock. And you know what, we still get zero. Nothing. So there is no way he can tune it because he has no idea what the existing trims are.

So the car is back with Jon Martin to be looked at tomorrow. Anybody have any idea what kind of evil witchcraft has plagued my car this time around? I'm beginning to think that the issues I had with my old Austin-Healy with Lucas ignition was nothing like the nightmare I've experienced of late.
 
Just got off the phone with Jon. Seems the rear cylinder bank pre-cat O2 sensor is not reading. Don't know why as it was before the install. I did have to take that header off in order to have an EGT bung welded in it but I was very careful with the sensor and never contaminated it with grease or anything. The connector will only let you plug it in one way. We are both scratching our heads on this one. More to come I'm sure of it.
 
Thanks SOHC for the direct suggestion.

We are all good to go as it was a simple switch of the O2 sensors on the rear bank. Everything is as it should be and the car is at the tuner. We're all good and making progress.
 
sohc_mshue said:
Get this http://www.scienceofspeed.com/produ...roducts/NSX/ScienceofSpeed/EMS_1995-2005_NSX/

Stop messing around with a piggyback when there are better options.
Click to expand...

icon14.gif


This is the real solution.
 
^^^^^^^^^^Bingo.

I've spent better money on rebuilding the turbos, upgrading the controllers and a great Zeitronix gauge system with alarms. The F/IC will do what I need at a quarter of the price. Especially in the hands of a tuner like Bisi. But thanks for the suggestions.
 
kookoo4nsx said:
Great solution? There is nothing wrong with his FIC. Dropping 2 grand on an AEM series 2 is fine if you are made of money.
Click to expand...

If you trust an unknown condition in your tuning solution then by all means have at it. The stock ECU is constantly changing and adapting to environmental conditions and to the unusual conditions of the forced induction system you are trying to hide from the stock ECU.
 
hybrdthry911 said:
If you trust an unknown condition in your tuning solution then by all means have at it. The stock ECU is constantly changing and adapting to environmental conditions and to the unusual conditions of the forced induction system you are trying to hide from the stock ECU.
Click to expand...

While you are correct about the ECU adapting to environmental conditions it is not adapting to anything while in boost or open loop. The issues with the F/IC are not the WOT boost part of the tune it is the closed loop parts of the tune that needs the time and care to perfect. I have run the AEM ECU and the F/IC on both turbo and SC it is a very reliable and repeatable solution while in open loop, and if the time is taken to work on the closed loop portion of the tune the car will run, start, and drive like OEM.

The fact that the OEM ECU is adapting is a good thing, that is what it was designed and programmed to do. Most stand-a-lone tunes I have looked at are not a complete tune, I have yet to see a cal file that takes advantage of the Baro built into the AEM ECU (not a big deal on N/A speed density, TPS based tunes), many if not most have not corrected the original output mapping error that is in the original startup tune put out by AEM, very few can and do setup knock control, very few have made any attempt to use the traction control, idle feeback, and even fewer setup the O2 feedback. The AEM ECU and especially the new Series 2 units are amazing pieces of hardware but many tuners, based on the tune files I have accumulated over the past 10 years, have setup these cars to simply run.

If you take a stand-a-lone ECU and program it for use in Miami then move the car to Denver it should adapt, it can adapt, but most do not because the tune is not complete. Your tuner will tell you that based on the large variance in the environment you need to retune your car. That is what the OEM ECU does and the AEM ECU can do it as well if you do the work. The F/IC does not have to adapt it just needs to sit back and let the OEM ECU do the job. In closed loop the only thing the F/IC has to do is correct for larger injectors. In wide open throttle the F/IC has stable open loop inputs to control from the ECU.

The F/IC has some issues but they can be dealt with. In a low boost OBDII setup the F/IC is a very good option regardless of price. Like any aftermarket product you put on your car it always comes down to execution, you can put the AEM Series 2 ECU on your car and have lots of issues with an improper tune and you can put an F/IC on an OBDII NSX and have little to no issues if it is tuned correctly.

Dave
 
DDozier said:
While you are correct about the ECU adapting to environmental conditions it is not adapting to anything while in boost or open loop. The issues with the F/IC are not the WOT boost part of the tune it is the closed loop parts of the tune that needs the time and care to perfect. I have run the AEM ECU and the F/IC on both turbo and SC it is a very reliable and repeatable solution while in open loop, and if the time is taken to work on the closed loop portion of the tune the car will run, start, and drive like OEM.

The fact that the OEM ECU is adapting is a good thing, that is what it was designed and programmed to do. Most stand-a-lone tunes I have looked at are not a complete tune, I have yet to see a cal file that takes advantage of the Baro built into the AEM ECU (not a big deal on N/A speed density, TPS based tunes), many if not most have not corrected the original output mapping error that is in the original startup tune put out by AEM, very few can and do setup knock control, very few have made any attempt to use the traction control, idle feeback, and even fewer setup the O2 feedback. The AEM ECU and especially the new Series 2 units are amazing pieces of hardware but many tuners, based on the tune files I have accumulated over the past 10 years, have setup these cars to simply run.

If you take a stand-a-lone ECU and program it for use in Miami then move the car to Denver it should adapt, it can adapt, but most do not because the tune is not complete. Your tuner will tell you that based on the large variance in the environment you need to retune your car. That is what the OEM ECU does and the AEM ECU can do it as well if you do the work. The F/IC does not have to adapt it just needs to sit back and let the OEM ECU do the job. In closed loop the only thing the F/IC has to do is correct for larger injectors. In wide open throttle the F/IC has stable open loop inputs to control from the ECU.

The F/IC has some issues but they can be dealt with. In a low boost OBDII setup the F/IC is a very good option regardless of price. Like any aftermarket product you put on your car it always comes down to execution, you can put the AEM Series 2 ECU on your car and have lots of issues with an improper tune and you can put an F/IC on an OBDII NSX and have little to no issues if it is tuned correctly.

Dave
Click to expand...

As with any system you can only get as much out of the system as you put in, I just think you can get more out of a standalone is all. Obviously a crappy tune on a standalone doesn't do any better than a tune on a piggyback. You're biggest argument for the FIC appears to be that most people don't use the standalone to it's capacity so why not just run an FIC? I'll agree most tuner's don't setup the systems in part because they can't simulate all of the conditions and tune for them. Think about how much time Honda likely spends tuning each engine for the various environmental conditions and elevations. Typical tunes are done within a matter of hours. Most people wouldn't find it practical to spend as much time as say honda would on every aspect of the tune. Many will say you don't have to tune for all conditions with a piggyback, the stock ecu is still there doing that for you but it never seems to work out that way. In it's attempt to adapt it can do more harm that good at times.

You just have limited control with the stock ECU adapting. It might work for many people but IMO with an aftermarket turbo system I would want to be able to tune every area of the maps to my values not what the stock ECU wants. What if you want non oem values during closed loop? Want 3-4 MPG more than stock?

WOT tuning isn't the tough part it's the other areas that need time. It's also where your battle with the stock ECU will be fought. The OP is fighting the battle before he has even started he can't even get a solid reading on his fuel trims.
 
hybrdthry911 said:
As with any system you can only get as much out of the system as you put in, I just think you can get more out of a standalone is all. Obviously a crappy tune on a standalone doesn't do any better than a tune on a piggyback. You're biggest argument for the FIC appears to be that most people don't use the standalone to it's capacity so why not just run an FIC? I'll agree most tuner's don't setup the systems in part because they can't simulate all of the conditions and tune for them. Think about how much time Honda likely spends tuning each engine for the various environmental conditions and elevations. Typical tunes are done within a matter of hours. Most people wouldn't find it practical to spend as much time as say honda would on every aspect of the tune. Many will say you don't have to tune for all conditions with a piggyback, the stock ecu is still there doing that for you but it never seems to work out that way. In it's attempt to adapt it can do more harm that good at times.

You just have limited control with the stock ECU adapting. It might work for many people but IMO with an aftermarket turbo system I would want to be able to tune every area of the maps to my values not what the stock ECU wants. What if you want non oem values during closed loop? Want 3-4 MPG more than stock?

WOT tuning isn't the tough part it's the other areas that need time. It's also where your battle with the stock ECU will be fought. The OP is fighting the battle before he has even started he can't even get a solid reading on his fuel trims.
Click to expand...

Everything you stated is true. Most people have been able to simply plug in an F/IC, go to their favorite tuner and within a couple of hours have their car tuned to acceptable levels. Some more, some less.

After finding that my front and rear O2 sensors were swapped on one bank, the car ran much better and the fuel trims did reappear. But the tuner was unable to tune the car because he stated one bank was reading negative trims and the other bank was reading positive numbers.

I'm picking the car back up this afternoon and will run my own scanner and will pull logs with the F/IC and with my Zeitronix. Hopefully I can find why the trims can't play nice and get it tuned after that.

If I can't, it will go back to Power Honda and Jon Martin. If he can't figure it out, it looks like I'll be shelling out $2k for an AEM EMS Series 2. I'm not real happy today.
 
Update: Picked up the car from Bisi. He had a race team in and was prepping their car for an all day session on the dyno. We talked and he stated that the front bank was pulling +20 and the rear bank was minus 30 on the fuel trims and he just didn't feel comfortable trying to tun it with each bank so far off. He tried with the F/IC piggybacked and with the OEM ECU only. Couldn't get the trims to settle down. I drove the car home very carefully. It ran like shit the whole way, nothing like the way I took it to him.

Pulled it in the garage and hooked my scanner to it. at idle I was getting the following readings;

  • ST FTAM1 - 0.0
  • LT FTAM1 - +3.9
  • ST FTRM2 - 0.0
  • LT FTRM2 - MINUS 21.9
At 2k I got the following readings;

  • ST FTAM1 - MINUS .08
  • LT FTAM1 - +3.9
  • ST FTRM2 - MINUS .08
  • LT FTRM2 - MINUS 21.9
OK, so everything was consistent, the Boomslang was still connected to the ECU, looked at all the wires and everything was tight. I did notice that my CCU fan was no longer working and that the drivers side speaker wasn't working so I thought, what the hell, let's pull the clock/ECU fuse and let it reset. Waited 30 seconds and put the fuse back in. Started the car and you know what happened?


The fuel trims matched. The voltages were very close. The car idled and revved 1000% better and everything was stable. I restarted the car several times and the short and long trims were stable and similar every time and at all rpm's. In short, there was nothing wrong and a quick reset of the OEM ECU was all that was needed. Now to drive the car back to Ontario for one more go at a tune...
 
OK, update time. Took the car back to Bisi for what I thought would be tune day. I was so excited. I figured third time would be a charm.

Drove the car there and plugged in my scanner to see that the fuel trims were consistent and in open loop. Nope. We spent the next three hours chasing fuel trims that were +30 on one bank and -40 on the other. Reset the ECU and tried again and the trims would reverse! I shit you not. We reset the ECU several times and occasionally it would take and the AFR's would look good and then all of a sudden take off again.

As a last resort we unplugged the F/IC and plugged back into the ECU. Reset it and all was right with the world. Zero trims, open loop on both systems and the car idled as it should. So do I have a bad F/IC and if so what is it going to cost me to have AEM look it over and fix what is wrong? We re-flashed the F/IC three times today. It looked as if it should work.

And before any one else chimes saying the EMS Series 2 is the greatest thing since sliced bread, F/IC has a good track record of doing the job on an NSX. Just not mine at the moment. I am looking into going EMS but having a very hard time grasping 1) why my F/IC is not playing nice and 2) the cost of EMS plus harness.
 
F/IC new or used?

Are the stock primary O2's wired into the F/IC? You will have to look very closely at the wire harness and make sure they are not wired in.

Something is not adding up resetting the oem ecu resets the trims to zero if the O2 data did not change the same issue with trims would keep coming back like they did. Thinking......

When you bypass the F/IC your long term fuel trims should have gone -40 to -50 for both banks if you did not change the injectors. Did your trims move a lot when you bypasses the F/IC?

Sorry for all the questions but this does not make since. Is it possible when they replaced the engine harness the bank 1 sensor 1 and bank 2 sensor 1 got reversed?

Dave
 
Answers to your question are attached below in RED.
DDozier said:
F/IC new or used?

Are the stock primary O2's wired into the F/IC? You will have to look very closely at the wire harness and make sure they are not wired in. - No. Per your instructions they are not wired into the F/IC.

Something is not adding up resetting the oem ecu resets the trims to zero if the O2 data did not change the same issue with trims would keep coming back like they did. Thinking...... - I just reloaded the calibration software and thought I had something. Fired up the car and had open loops with no trims. Drove a little and it didn't take long to go to closed loops but at least the trims were the same negative numbers for both banks.

When you bypass the F/IC your long term fuel trims should have gone -40 to -50 for both banks if you did not change the injectors. Did your trims move a lot when you bypasses the F/IC? - when we bypassed the F/IC both loops were open and all trims reset to zero across the board.

Sorry for all the questions but this does not make since. Is it possible when they replaced the engine harness the bank 1 sensor 1 and bank 2 sensor 1 got reversed? - We got to thinking about that too. But we changed the rear O2's to mini-cats so I doubt that would have caused a code. Especially since the +'s and -'s would swap places from front to rear and back again. Doubtful it would have been a sensor or multiple sensors. It leads me to the F/IC either not taking the calibration software or a bad board on the F/IC. I don't see where the Boomslang would be off pin wise. I'll know tomorrow night when I try RYU's F/IC.

Dave
Click to expand...
 
RYU said:
Is there anything in the boomslang harness, where if crosswired somewhere, would cause this?
Click to expand...

We can look tomorrow night as I have the schematic. I doubt it though. I'm thinking it is a hardware/software F/IC issue but we'll know better when I plug yours in. Thanks for the assistance in advance.
 
dynomike said:
it sounds like you have the o2 sensors plugged into the wrong banks. If the o2 are not connected to the fic than there is no way it is the FIC.
Click to expand...
Thanks for chiming in here. I'm not sure that would be it. Even if I did have them swapped on the rear O2's, running the mini-cats would not give enough of a reading to throw the banks + and then - with that much of a swing. And by pulling the F/IC out of the equation, the stock ECU had everything perfect. I'm still leaning toward the F/IC and it could be the board or software. I'll know more tomorrow.

Thanks RYU for the assist and I will cover any damage that may occur to your F/IC in my care. I PM'ed you.
 
Hopefully it is the f/ic. Hoping. Like I said earlier, kookoo said his f/ic took a dump, and with your luck this might be it. If the map is bad in the fic like kookoo's, that would throw off everything. I hope you get it figured out JC, dont give up. You are almost there. It will all be worth it in the end, despite what les says about turbos lol. Tomorrow you are fixing the fic, I'm cutting up that magnaflow pos restrictive exhaust. Only thing i like about it is the welds Will did on it lol. Anyone got advice on cutting open the magnaflow. Cut the top or cut both sides off.
 
SuperSonic said:
despite what les says about turbos lol.
Click to expand...

Well I could install this for less than 1K.

http://nitrousexpress.com/product-details.php?id=1208

When you hit boost I'll hit this and we'll see who's looking at who in their rear view mirror.:wink: And I would still have a totally reliable, headache free daily driven CTSC.:tongue:

JC, not trying to rain on your parade, just Jason's as I know what you've been going through my friend. <!-- / message --><!-- sig -->
__________________
 
Not sure why you don't like the magnaflow. There seems to be no HP gain/loss from those that have the magnaflow or the borla. I'm sure you could just bolt on the borla without much work. Sometimes I wish the borla was louder but it is nice to be able to speak on my cell phone while highway driving.

I'm not sure what is going on with your car but why not place a call to AEM's tech support? They were very helpful with what turned out to be a fried board on the F/IC. Fixed it no charge and it was several months out of warranty. I know of at least 2 other members that had a bad F/IC.

As an update, my car runs flawlessly. See quick video. http://www.youtube.com/watch?v=qvtewi3Wst8
 
Last edited:
I did place a call to AEM support and also started a new thread on their support board. I am waiting to hear anything back. I did go back and download the latest software and updates and loaded them back on the F/IC. We'll see if that moves this along any.
 

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