troubles with boosted E38 SD tune

[jb0322]

i have been troubleshooting this problem for the last week and cant seem to figure out what is going on. I just wanted to post my tune and short log of the truck to rule out if its in the tune or not. The problem im having is that the truck keeps going lean under and type of throttle and was not doing this previous of changing things. So long story short i had the truck running getting into boost to start getting a base tune down and all was fine then i lost all fuel pressure. So took the tank out and it turns out i blew a line so i changed the line and all was fine until it happened again so i went a totally different route to solve the problem. While doing so i changed the way the wiring was for the pump.. before when it was working i had the fpcm still intact with a racetronix hotwire kit that was a plug and play to the stock plug and it wouldn't build fuel pressure until you cranked it so i decided while i was doing all of this to directly wire the hotwire kit to a ignition source to have fuel pressure key on so it was always constant at key on. So after doing all this the truck goes dead lean in boost and out of boost but wasn't doing this previously. Any ideas of what to do or what it could be. I have dropped the tank again and pump feed line is good and everything from there to the regulator is perfect. Running a base of 58 psi with 1000cc injectors and a walbro 450 pump.

2007 Silverado SD Tune 2 BAR 8-6-16 .hpt
Before Fuel Changes.hpl
After Fuel Change.hpl

[SultanHassanMasTuning]

thats one unrealistic VE, i would populate your maf as well

[jb0322]

thats one unrealistic VE, i would populate your maf as well

Yeah i just realized that the wrong tune i posted the other one i have is a work in progress im not talking about the ve but im wondering if anything else inthe tune is off. Also this is a OLSD tune only no MAF

[jb0322]

anybody? need some input on this

[cc-rider]

What made you go without the FPCM? With those 1000 injectors, you probably could have got away with even the stock pump. What is your total set up?

I'll take a look tonight when I get to my computer that has HPt on it. But tell us more about all the mods you've made...

[jb0322]

What made you go without the FPCM? With those 1000 injectors, you probably could have got away with even the stock pump. What is your total set up?

I'll take a look tonight when I get to my computer that has HPt on it. But tell us more about all the mods you've made...

Went with a complete stand alone return style fuel system. Was return less before with fpcm that I didn't want to fool with problems. The truck is a stock bottom end 5.3l ,full bolt ons with twin 63/68 Borg Warner turbos. Running 1000cc injetorss with a external regulator and a walbro 450 pump

[cc-rider]

Is your fuel pressure regulator boost referenced? If you're not boost referenced...then there is your problem.

I see your flow rate vs pressure delta table is flatlined with one single value. Hopefully some of the pro's who have done these systems before chime in. If I remember right, the flow rate should only be flatlined after a certain point (after the point where the boost reference comes in?). Research it a bit. But what you have to think about here is that the "pressure delta" in that table is not just the FP. But its a combination of the FP and the MAP. The injector is constantly seeing changing MAP conditions that its trying to fire fuel into. I know that boost/vac referenced regulators are supposed to account for all this. But I'm no pro. Read up on it here.

But hopefully one of the pro's chime in.

[jb0322]

I do have a boost referenced regulator and from what i have heard you suppose to flat-line the IFR table when you have an external regulator but i could be wrong. Just figured if the system doesn't see any pressure correlation from not using any of the stock fueling system then just tell it to see the same pressure table acorss the board to trick it to think its meeting the 58 psi requirement. But any help in the right direction would help.

[cc-rider]

Have you completely unplugged the FPCM? I've heard that needs to be done to get rid of some effects in the tune. Maybe its still messing with your tune if its still plugged in. Again...just throwing some stuff out there that I remember reading in the past here (and I may not be recalling it correctly).

[jb0322]

Have you completely unplugged the FPCM? I've heard that needs to be done to get rid of some effects in the tune. Maybe its still messing with your tune if its still plugged in. Again...just throwing some stuff out there that I remember reading in the past here (and I may not be recalling it correctly).

Well to be honest the system was working when the fpcm was plugged straight into the racetronix harness I'm using and when I converted it to where the pump comes on key on and fpcm deleted it started to do this so I can't figure out out. Tempted to put it all back the way it was ans see what it does

[jb0322]

This is a log from today first hit making only a couple of pounds but not going lean then after doing it a couple of times it gets gradually worse with going lean throughout the rest of the run in places where in the beginning it was not doing that. Its driving me insane. Can anyone help


9-14-16.hpl

[10_SS]

add your O2's to the log, I always compare Widebands to O2's for sanity checking.

Aside from that, I see two spots where your at 4000rpm and only 110kpa load, and you have good fueling, 0.80 commanded, 0.81 measured. 5.9ms injector pulse.

There are spots where your at 110kpa and your still closed loop... need to fix that.

Later on I see your once again at 4000rpm but this time your MAP is 135kpa, 0.80 commanded 1.10 measured, very lean. However your at 8ms injector.

Any spot above 115kpa I see your start to lean out, even on the higher boost run around 8:17:059 you start at 116kpa and your fueling is actually good, then as you build boost it leans out, below 116kpa things seem fine.

So I would say maybe your always ok at 115kpa, and as you go higher boost you lean out? Maybe it's more consistent than you think. In fact, you never hit the higher boost early on, you never entered the higher MAP cells so no, it was not fine at first then leaned out. I think it is always lean in the higher cells, on this log anyway 9-14-16.hpl.

Then, start making consistent WOT runs, starting from 1000rpm to 2000rpm each time... check them... then 1000-2500rpm check them, etc. Keep moving higher and higher until you see what's going on. Always do this WOT though to make it easier to add fuel in the same cells each time until you are sure either it is helping or there is no change.

Never try to tune this type of problem by suddenly hitting WOT at 3500rpm... start low rpm and roll into it... get that method working at all RPMs with good fueling then move on to going WOT at 3500rpm. Two totally different problems. You will find your Wideband will lag behind actual fueling just a bit.. this makes tuning by "stab the throttle at 3500rpm for 1 sec" method impossible to tune.

[GHuggins]

Good advice 10 SS... I can't look at the tune right now, but I would also add to try with the fpcm unplugged and if by chance you changed any of the VE mapping points to put them back to stock.

[jb0322]

add your O2's to the log, I always compare Widebands to O2's for sanity checking.

Aside from that, I see two spots where your at 4000rpm and only 110kpa load, and you have good fueling, 0.80 commanded, 0.81 measured. 5.9ms injector pulse.

There are spots where your at 110kpa and your still closed loop... need to fix that.

Later on I see your once again at 4000rpm but this time your MAP is 135kpa, 0.80 commanded 1.10 measured, very lean. However your at 8ms injector.

Any spot above 115kpa I see your start to lean out, even on the higher boost run around 8:17:059 you start at 116kpa and your fueling is actually good, then as you build boost it leans out, below 116kpa things seem fine.

So I would say maybe your always ok at 115kpa, and as you go higher boost you lean out? Maybe it's more consistent than you think. In fact, you never hit the higher boost early on, you never entered the higher MAP cells so no, it was not fine at first then leaned out. I think it is always lean in the higher cells, on this log anyway 9-14-16.hpl.

Then, start making consistent WOT runs, starting from 1000rpm to 2000rpm each time... check them... then 1000-2500rpm check them, etc. Keep moving higher and higher until you see what's going on. Always do this WOT though to make it easier to add fuel in the same cells each time until you are sure either it is helping or there is no change.

Never try to tune this type of problem by suddenly hitting WOT at 3500rpm... start low rpm and roll into it... get that method working at all RPMs with good fueling then move on to going WOT at 3500rpm. Two totally different problems. You will find your Wideband will lag behind actual fueling just a bit.. this makes tuning by "stab the throttle at 3500rpm for 1 sec" method impossible to tune.

I dont have any NB O2's on the truck currently. Thought i could tune the truck off the WB.

How is it that in some areas of 110 kpa i am in closed loop? im running complete OLSD tune didnt think it was going into closed loop at all can you explain further?

Yeah i understand where your coming from but with it acting like this im worried to even go WOT to test what you speak of and gradually go up to WOT bc it will go lean before even reaching that point. Where would you suggest start? Adding percent error EQ to the VE and see if it helps?

[jb0322]

Good advice 10 SS... I can't look at the tune right now, but I would also add to try with the fpcm unplugged and if by chance you changed any of the VE mapping points to put them back to stock.

The FPCM is unplugged and i have tweaked the VE mapping to meet my needs but your suggesting to go back to the stock VVE mapping?

[GHuggins]

Only stock map points. In other words the sections that the vve table are broken down into. That's only if you've ever modified them.

[GHuggins]

Just looked at the tune - no wonder it's going lean... Your injection timing is advanced 55 degrees - never good for FI...... It appears your FPCM is killed in the tune, so that part should be right... I also assume your running a boost referenced regulator and it is hooked up. Injection timing is the only issue I see off hand and I know that probably wasn't changed with the pump, but that's all I see...

[10_SS]

I dont have any NB O2's on the truck currently. Thought i could tune the truck off the WB.

How is it that in some areas of 110 kpa i am in closed loop? im running complete OLSD tune didnt think it was going into closed loop at all can you explain further?

Yeah i understand where your coming from but with it acting like this im worried to even go WOT to test what you speak of and gradually go up to WOT bc it will go lean before even reaching that point. Where would you suggest start? Adding percent error EQ to the VE and see if it helps?

ahh, no 02's that's fine just curious. By closed loop I mean closed loop fueling target (commanded EQ ratio), which is lambda 1.0 which is 14.67afr... when you enter PE mode (another form of open loop) fueling drops 0.8 lambda. So what I meant was sometimes at 110-115kpa your commanded EQ is still 1.0, so this is probably not PE mode, unless you have it setup differently? Basically when your Commanded EQ Ratio changes from 1.0 then your in PE mode, and that shoulo happen below 100kpa in all cases. This wont fix your lean at 4000rpm and 130kpa, but just something that needs to get fixed at some point... maybe it's set at 18% PE TPS and 90kpa MAP and your only at 16% PE TPS at 115kpa... just lower the TPS value to say 10%. You'll notice the ZL1 or ZR1 enter PE my TPS, not MAP... MAP is set low like 15kpa, and purely off TPS value. But you have to log PE TPS not normal TPS... or something like that.

If your that worried and have done everything GHuggins has recommended then you can add 15% to whatever is in your VE tables above 100kpa... I didn't see any knock so this is good, haven't paid attention 100% to the entire thread. going WOT down low RPM should not build too much boost, not much more then you've allready been dealing with. To be safe you could pull 10 deg of timing above 110kpa, whatever that airflow is. Put it back when you have if figured out.

For whatever reason sounds like your fuel pressure changed at WOT/Boosty, and if it's not dropping at WOT under boost and you think you wont change how it's setup and you cant find anything wrong then it's time to start adding fuel using the VE table. If 10-15% does nothing, then add 10% more... if that does nothing and your sure fuel pressure at the injectors isnt dropping then something is up.

[jb0322]

Just looked at the tune - no wonder it's going lean... Your injection timing is advanced 55 degrees - never good for FI...... It appears your FPCM is killed in the tune, so that part should be right... I also assume your running a boost referenced regulator and it is hooked up. Injection timing is the only issue I see off hand and I know that probably wasn't changed with the pump, but that's all I see...

Just out of curiosity what is injection timing suppose to be this is how the parameters were set before i did anything to the truck from NA. So i haven't changed it?

[GHuggins]

ahh, no 02's that's fine just curious. By closed loop I mean closed loop fueling target (commanded EQ ratio), which is lambda 1.0 which is 14.67afr... when you enter PE mode (another form of open loop) fueling drops 0.8 lambda. So what I meant was sometimes at 110-115kpa your commanded EQ is still 1.0, so this is probably not PE mode, unless you have it setup differently? Basically when your Commanded EQ Ratio changes from 1.0 then your in PE mode, and that shoulo happen below 100kpa in all cases. This wont fix your lean at 4000rpm and 130kpa, but just something that needs to get fixed at some point... maybe it's set at 18% PE TPS and 90kpa MAP and your only at 16% PE TPS at 115kpa... just lower the TPS value to say 10%. You'll notice the ZL1 or ZR1 enter PE my TPS, not MAP... MAP is set low like 15kpa, and purely off TPS value. But you have to log PE TPS not normal TPS... or something like that.

If your that worried and have done everything GHuggins has recommended then you can add 15% to whatever is in your VE tables above 100kpa... I didn't see any knock so this is good, haven't paid attention 100% to the entire thread. going WOT down low RPM should not build too much boost, not much more then you've allready been dealing with. To be safe you could pull 10 deg of timing above 110kpa, whatever that airflow is. Put it back when you have if figured out.

For whatever reason sounds like your fuel pressure changed at WOT/Boosty, and if it's not dropping at WOT under boost and you think you wont change how it's setup and you cant find anything wrong then it's time to start adding fuel using the VE table. If 10-15% does nothing, then add 10% more... if that does nothing and your sure fuel pressure at the injectors isnt dropping then something is up.

This actually brings up something that I did not see being asked - heck I didn't even ask it... Wiring was changed to the pump - has fuel pressure been checked during a pull or wot run of any sort since? Even if your out on the road you can hook up a mechanical gauge and make a quick 3rd gear pull and see if it's dropping under boost - your boost referenced line could have blown off the intake... Or something may just be off with the wiring?

For turbos - to get them spoil quicker and to keep fuel from being blown out the exhaust - put your ect table back to stock and add 15 to your boundary table - this will help even with keeping the stock boundary curve...