Frustrated

[07TurboTruck]

Alright guys, I'm just about at my wits end. Been messing with this truck for some time now and I can NOT get it to make a clean run without coughing and cutting power. Seems like its the traction control system that is cutting power, but it's all turned off. Here is my tune file and a log file... Someone please help. This thing is giving me gray hairs lol

Also, on the log file, the wideband reading is not accurate. I have a separate afr meter and commanded afr is very close to, if not right on, actual afr.

Specs on the truck are as follows:

Stock 4.8L long block with ARP head studs, TSP 220r cam, 4L80e tranny, 4.11 gears, 160lb FIC injectors, stock fuel system replaced with 16 gallon fuel cell with MagnaFuel 750 pump, Aeromotive fpr, and edelbrock rails. Might be missing some things, just ask. Thanks in advance.

[GHuggins]

Couple of quetions or points depending on how you look at it? First I noticed your running in SD, but your still datalogging MAF. That needs to be taken out of the pid list otherwise will throw your log tables off. Second - I assume there's a reason why your running in the high 10's for PE? That should be around 12 to 12.5 for a NA motor... Timing looks a little sketchy, but also assume there's a reason for that. Then you have a very high engine demanding fuel system even though it's NA? Everything actually looks like it's setup for serious boost on a FI motor, but even so it's still a touch rich for that. I would say to lean it up and see if your coughing goes away. Even FI motors in certain cituations can cough on that fueling. Granted it does typically have to be a touch richer for FI to cough, but still it is still possible. Otherwise nothing jumped right out waiving it's hands in the air with torque management or traction control in either engine or trans. The only thing I did see that you might possibly want to change is your accel based rpm limiter and you just need to zero it out. That's a function to change rev limit if accelerating too quickly.

Just some thoughts.

[2xLS1]

Couple of quetions or points depending on how you look at it? First I noticed your running in SD, but your still datalogging MAF. That needs to be taken out of the pid list otherwise will throw your log tables off. Second - I assume there's a reason why your running in the high 10's for PE? That should be around 12 to 12.5 for a NA motor... Timing looks a little sketchy, but also assume there's a reason for that. Then you have a very high engine demanding fuel system even though it's NA? Everything actually looks like it's setup for serious boost on a FI motor, but even so it's still a touch rich for that. I would say to lean it up and see if your coughing goes away. Even FI motors in certain cituations can cough on that fueling. Granted it does typically have to be a touch richer for FI to cough, but still it is still possible. Otherwise nothing jumped right out waiving it's hands in the air with torque management or traction control in either engine or trans. The only thing I did see that you might possibly want to change is your accel based rpm limiter and you just need to zero it out. That's a function to change rev limit if accelerating too quickly.

Just some thoughts.

Not sure what you are looking at but the OP is commanding 12.89:1 in PE and 12.25:1 in BE is what I see. And since I'm seeing 230kPa on the MAP I'd say it is not a NA vehicle.

To the OP, I'd say if you find out what is making the timing completely drop out you'll find your problem. Looking at the tune it looks like all the obvious things like burst knock etc have been zeroed. The only thing I see that still could be pulling timing (not kr) is the torque management timing retard hasn't been zeroed. You might give that a try. Also it this is a vehicle that sees some part throttle driving (other than idle and WOT like a track only car) your timing table is a little weird in the part throttle areas. And if you do remove the MAF PID your timing table histogram will populate more accurately.

timing dip.JPG

[GHuggins]

I'm going to have to try updating everything again because I'm definitely not seeing anything like that when I watched it earlier. Plus I recall having this problem watching another person's log and I've recently even been having trouble viewing my own logs correctly. So yeah. Going to try updating.

But running that much boost at a 13:1 a/f?

I do remember doing the math in the tune and unless stoichio was changed which would change commanded pe, which I didn't check, pe should have been commanding high 10's. Don't have my laptop to recheck things, so I don't know.

[07TurboTruck]

Sorry, I left out a pretty crucial bit of info lol. The truck also has a Precision 7475 turbo on it, and is running on e85. The fuel system is that big because I ultimately plan on doing a boosted 408 or something close to that. Might the timing seem weird since I had to scale the tune so much for the injectors? I read up on how to properly scale for bigger injectors, and I'm pretty sure I did it right. I have stoich set at 14.7 across the board, which I know isn't right for e85 but doing the calculations for 9.85:1 separately, the commanded vs actual is pretty darn close. I'll zero out TM timing retard and see what that does. Thanks for the help guys.

[GHuggins]

9.85:1? I think unless I'm wrong it was 10.85:1?

The timing cut from 2xls1's pic that he pulled from the log apears to be your problem. I can't look at the tune again as I don't currently have my laptop, but is there an EQ timing table that's possibly causing this? 230's map, I don't remember you map settings. Is it possible it's hitting it's limit or did you have those as no error? Or just something didn't get scaled that should have been. Did you get all of the timing correction and multiplier tables? Just something else to check. Sorry can't be more help right now.

[07TurboTruck]

Everything I've read says that stoich value for e85 is ~ 9.85:1. As far as scaling the tune, Im only pretty sure I did it right, not 100% sure. What timing correction and multipliers need attention when scaling a tune? I'm sure I could have missed some things. I knew the timing cut was the problem, was curious as to what could cause it.