Stalling trying to burnout at the track?

Chuck Leeper

Toxic old bastard
Staff member
I have no idea how to adjust on this thing to be honest
Then park it before you drive over the crank!
Tried to upload multiple file types and they are either too large or not supported so best I could do is a screenshot.
Did you zip those files before you tried to post them?
If not, that may be your issue.
 

longbedGTs

high on gas fumes
I agree with Chuck here. Even though the problem occurs with motion(ie:driving), there are obvious problems at idle. FP shouldn't be at 71 and oil pressure shouldn't be either(unless the engine was built with tight tolerances or whatever). You said this is your first GN. Did you just buy this car? Did it come with these issues or did they develop after you bought the car? Very odd that someone would be running such a stout combo, yet they would allow these issues to surface...or even worse, sell the car to a newbie(no offense) knowing there are problems. Either way, no worries. This site is full of knowledgeable people willing to help.
 

dynoman

Well-Known Member
Then park it before you drive over the crank!
I said the same thing to myself just before I read your post . lol
I would get the fuel & oil pressure reading straightened out first . You can't easily tune without knowing your fuel pressure .
Norbs does remote tuning on XFI , E85
 

REISJSR

New Member
I agree with Chuck here. Even though the problem occurs with motion(ie:driving), there are obvious problems at idle. FP shouldn't be at 71 and oil pressure shouldn't be either(unless the engine was built with tight tolerances or whatever). You said this is your first GN. Did you just buy this car? Did it come with these issues or did they develop after you bought the car? Very odd that someone would be running such a stout combo, yet they would allow these issues to surface...or even worse, sell the car to a newbie(no offense) knowing there are problems. Either way, no worries. This site is full of knowledgeable people willing to help.
You guys are all awesome and I appreciate your assistance. No offense taken brother, I will be the first one to say I spent 5 years as a Porsche tech and a 10 years as a Mercedes tech, and I’m so clueless with this car it’s comical. I’m as clueless as someone who has never worked on a car.

These issues all started after I purchased it, the guy who owned it before me was a gentleman and built it right. I just don’t know what I did.

The guy I bought it from is a man of almost no words and even less texting, I did manage to get a text from him a few minutes ago, the 71PSI is a ECU default, he installed an oil pressure gauge separately which shows in spec, the 71PSI for fuel is because he doesn’t have the fuel pressure monitored in the XFI system so that’s a bit of a relief.

The only thing I can think of is I bought it, put it into flex fuel mode, filled up with flex fuel, and accidentally hit the mode button on the auto meter boost controller. I don’t know if it switched it to a different untuned wastegate setting or something. I was playing with it a little bit ago and hit the mode button again and it started to run noticeably better and wasn’t stalling. Then again it just seems unlikely that would be the issue.

I do know the guy before me had it fully dialed in and nearly cried when it drive away
 

REISJSR

New Member
I said the same thing to myself just before I read your post . lol
I would get the fuel & oil pressure reading straightened out first . You can't easily tune without knowing your fuel pressure .
Norbs does remote tuning on XFI , E85
I need some Norbs in my life lol
 

Pronto

Believe nothing you hear and half of what you see.
You need to log fuel pressure. Whatever is going on it's going to ruin your engine unless you straighten it out. Norbs is an XFI expert. He can give direct information on what's going on. Look for the XFI folder "GCT" in your file explorer. It has all the "tunes" saved to your computer. If it never had a specific tune for your engine on E70 then your running on a generic tune or a base tune for who knows what. There may be other tunes in there for gasoline. In that folder there are a bunch of base tunes for several engines not just the TB v6. Hopefully the PO has named the tunes specific to the TB v6. The files will end with .gct so look for those. If you happen to know when the XFI was installed, any file date stamped around that time my be the TB v6 tunes. Take a screen shot of the file in the GCT folder and we can see what's in it. Also add the version of XFI your running.
 

Pronto

Believe nothing you hear and half of what you see.
When you say "put it in flex fuel mode" how did you that? With the XFI software or your talking about the boost controler? The boost controller will not effect the tune, only the boost ramp. https://www.autometer.com/pub/media/manual/2650-1706.pdf
I would use a 3 bar GM MAP to monitor your boost. The Autometer does have an output for data to be sent to the XFI if you want to do that.
 

REISJSR

New Member
When you say "put it in flex fuel mode" how did you that? With the XFI software or your talking about the boost controler? The boost controller will not effect the tune, only the boost ramp. https://www.autometer.com/pub/media/manual/2650-1706.pdf
I would use a 3 bar GM MAP to monitor your boost. The Autometer does have an output for data to be sent to the XFI if you want to do that.
Hey brother, put it in flex fuel mode in XFI which changes the tune for E85. It’s just a check box and apply click in the XFI.

The boost controller I believe already feeds data to the XFI at well.

Monitored fuel engine off key on 43 psi, idle 38psi, idle with Vaccum hose disconnected 43. Played with the regulator to provide exactly 43psi at idle with vaccum connected. Jumped each fuel pump and both are turning on. Fuel gauge is too short to monitor while driving with boost but really don’t suspect any issues with the way it was built and the pumps are less than a year old.

Verified timing with a light and by setting fixed timing mode in XFI and monitoring what degree the engine was at with idle, 1500rpm, 2000rpm, and 2500 changing each fixed timing setting and watching to see if timing matched the test mode spec I set. Timing is on.

Changed plugs to NGK TR6 with .26 gap. Plugs were at .28 previously and had NGK iridium plugs in there. They had residue from running e85 but otherwise not fouled or burning carbon or anything too weird.

That’s as far as I could get on Saturday. I logged a couple low boost runs and didn’t see knock or any timing issues but don’t have the log in front of me right now.

Pulling back into the garage with a quick stab of the throttle the engine still stalls.
 

Pronto

Believe nothing you hear and half of what you see.
Monitored fuel engine off key on 43 psi, idle 38psi, idle with Vaccum hose disconnected 43. Played with the regulator to provide exactly 43psi at idle with vaccum connected.
That's not how you set the fp. You need to research the XFI fp for E85.
You've been given information to help you. You need someone that is fully versed in XFI and using E85 to go over your tune, brother.
Verified timing with a light and by setting fixed timing mode in XFI and monitoring what degree the engine was at with idle, 1500rpm, 2000rpm, and 2500 changing each fixed timing setting and watching to see if timing matched the test mode spec I set. Timing is on.
You should research the timing marks on a TB to set the timing correctly.
 

Pronto

Believe nothing you hear and half of what you see.
BTW, have you confirmed you have a flex fuel sensor in the fuel line?
 

REISJSR

New Member
That's not how you set the fp. You need to research the XFI fp for E85.
You've been given information to help you. You need someone that is fully versed in XFI and using E85 to go over your tune, brother.

You should research the timing marks on a TB to set the timing correctly.
Weird. Won’t name drop but was working with a guy that came highly recommended on this very forum. I think everyone is very passionate about their own setup and their own flavor with GN’s. Just my two cents here.
I’ll do research
 

dynoman

Well-Known Member
Have you checked cam sync ?? It should be very close to 85 and steady with engine running , idle to wot .
 

SCOOBY DOO

I'M NOT A MONSTER, I'M JUST AHEAD OF THE CURVE!!!
This is one of the discussions I have with people who are thinking of buying one of these cars. Make sure you have a fuel management system on the car that YOU FULLY UNDERSTAND inside and out and can adust yourself. I always want owners of these cars to have a positive experience with them. Happy spooling.
 

REISJSR

New Member
Totally and appreciate your help/advice. I want to make it clear, I was not plugging around experimenting on my own, that is what I was instructed to do by a certain unnamed tuner that comes recommended by quite a few on this forum.

Needless to say, I won’t be moving forward with him. This is a bit tough, I’ve been in the automotive industry for 20+ years and haven’t had this much trouble working with base values, one off situations, vague info, and horribly user unfriendly stand-alone ecus ever. I think part of it is my generation came a little after these, I never really got to play around with “real” mechanic stuff you know. Tuning a Porsche, BMW, or AMG, or even my GT500 wasn’t a niche secret sauce of what works by each individual car that has already been cut into, built up, and chopped into whatever a previous owner wanted.

My GT500 was like, cool, this is what works with this setup, buy parts, install, watch values, make small adjustments, tons of support, the end. That was like duplo blocks compared to this, which is like doing differential equations in braille while drunk and missing one of the variables needed to make it work.

I like it, it’s a challenge, it’s just a learning curve, and a steep one.
 
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