mowton
May 19th, 2014, 09:47 PM
So we get in this awesome LS1 Turbo/MAFless/E85 transplant into a Nissan 240 the other day. It was supposedly tuned by a local pro but the customer says it just didn't run right. Long story short, decides to bring it in and let us have a go at it. First thing we do is to upgrade to a Custom Operating System to give us the Boost timing and fueling control. The file in the car is very strange and just doesn't look like anything we had ever seen before. Timing flat lined, IFR and associated data orders of magnitude away from reality and a crazy VE. Suffice it to say and in hindsight, I should have taken a stock file and start over, but thought we could "fix it".
Loaded COS/Cal file with IFR changes (so we thought), stock Timing and VE tables etc. but the first day just couldn't get the car to start or take any pedal. Google search that night, found a wealth of data on the injectors and next day we changed to that and the car started great, but again wouldn't take any pedal. Tried REP (all DTC's were shut off) but not the cause. Another frustrating day of checking MAP/TB/PC wiring, Turbo setup etc and we left again with no end in sight :-(
That night over a scotch and several tune/log session detailed reviews, it dawned on me that it really appeared that we weren't transitioning into Speed Density....had all the parameters updated (so I thought) to get the job done as I had hundreds of times before, but still looked like we were trying to run off the MAF table. Even had put 8 g/sec in the 1500 HZ cell to help in the SD transition. Car would start, idle great but just wouldn't take any pedal without snorting/stalling. Also found GM data for the injectors though I previously used a great Ford to GM conversion tool from DSTECK to generate more accurate data.
So, (looks like I am making a long story even longer :-) Sunday we head back to the shop to try a new file that I scrubbed to make sure I had covered all the MAF fail requirements. Loaded new file and guess what, same thing agggggghhhhhhhh, ready to burn it (the car). After a long breath, decided to go through the tune once more and actually read each tables description and what/why I set it to what it was out loud to my partner.......got down to the MAF rationality test and all was in order until I read "C2909 MAF TEST MIN BATT VOLTAGE" = 50 :sneaky: Why would anyone set this cell to 50 volts??????This was the reason we were never transitioning to SD. Put it back to stock 8 volts and all was well with the world again :mrgreen:
Thankfully the balance of the Sunday tune session went good and customer was more than happy with the 10 PSI of boost and 590/570 results from his otherwise stock LS1 power plant.
Moral of story....when you take in a Franken-setup and someone else's work, its best to go back to stock and start over the way you would do it!
Ed M
Loaded COS/Cal file with IFR changes (so we thought), stock Timing and VE tables etc. but the first day just couldn't get the car to start or take any pedal. Google search that night, found a wealth of data on the injectors and next day we changed to that and the car started great, but again wouldn't take any pedal. Tried REP (all DTC's were shut off) but not the cause. Another frustrating day of checking MAP/TB/PC wiring, Turbo setup etc and we left again with no end in sight :-(
That night over a scotch and several tune/log session detailed reviews, it dawned on me that it really appeared that we weren't transitioning into Speed Density....had all the parameters updated (so I thought) to get the job done as I had hundreds of times before, but still looked like we were trying to run off the MAF table. Even had put 8 g/sec in the 1500 HZ cell to help in the SD transition. Car would start, idle great but just wouldn't take any pedal without snorting/stalling. Also found GM data for the injectors though I previously used a great Ford to GM conversion tool from DSTECK to generate more accurate data.
So, (looks like I am making a long story even longer :-) Sunday we head back to the shop to try a new file that I scrubbed to make sure I had covered all the MAF fail requirements. Loaded new file and guess what, same thing agggggghhhhhhhh, ready to burn it (the car). After a long breath, decided to go through the tune once more and actually read each tables description and what/why I set it to what it was out loud to my partner.......got down to the MAF rationality test and all was in order until I read "C2909 MAF TEST MIN BATT VOLTAGE" = 50 :sneaky: Why would anyone set this cell to 50 volts??????This was the reason we were never transitioning to SD. Put it back to stock 8 volts and all was well with the world again :mrgreen:
Thankfully the balance of the Sunday tune session went good and customer was more than happy with the 10 PSI of boost and 590/570 results from his otherwise stock LS1 power plant.
Moral of story....when you take in a Franken-setup and someone else's work, its best to go back to stock and start over the way you would do it!
Ed M