Stalling trying to burnout at the track?

[REISJSR]

Hey everyone, went to the track last weekend every time I tried to burn out the engine would stall after the RPMs would come down. In normal operation driving around, drivability seems normal unless I blip the throttle trying to back out of a garage or pull into a parking spot, it will stall then as well. Due to this I have all but rules out transmission torque converter issues since it will happen at an idle with a small blip.

Anyone experienced anything like this? Fuel pressure isn’t an issue, happens with 93, E50, and E70 fuel, and regardless if I am in low or high boost.

During the run at WOT in 3rd the engine wanted to stumble a fair amount and kind of cut out like knock. In my normal car diagnosis opinion seems like a vaccum leak but I have no idea where’s used brake cleaner and propane and haven’t gotten idle to change.

Any help would be great guys

 

[hensleyt]

have you checked TPS and IAC. I like TPS around .36 and IAC 25

 

[hensleyt]

high speed I would check plugs

 

[REISJSR]

I have not. First GN and somewhat unfamiliar, also I don’t have much info on the tuning in XFI so didn’t know if it might stem from something that was setup wonky. I’ll check a couple plug, IAC, and TPS and report back. What if TPS or IAC is way out of spec?

 

[dynoman]

Review your logs from the XFI .... AF ratio , timing , knock , boost , FP , rpm , something will show up .

 

[hensleyt]

my bad I should have read your sig your car is way out of my skill level

 

[Chuck Leeper]

In my normal car diagnosis opinion

Does this include data logging?

 

[Pronto]

If you have datalogging (which you probably do) try to log a burnout like you did at the track. You could post the log on here for advice. Buick Grand National and Sy/Ty Classic xfi sportsman tech | Facebook

 

[REISJSR]

If you have datalogging (which you probably do) try to log a burnout like you did at the track. You could post the log on here for advice. Buick Grand National and Sy/Ty Classic xfi sportsman tech | Facebook

On it. Going to log today

 

[TIMINATOR]

How old is your MAP sensor? They get "slower" to react with age.
Most GN customers driveability issues I have found result in old O2, MAP, TPS sensors, or carboned up IAC. Thats where I start first. The transition phase, up or down in RPM is the most noticable time sensor issues start to show up
TIMINATOR

 

[REISJSR]

This is all kinda funky because I don’t know all how things have been setup. Something carboned up could definitely be it. Haven’t had a chance to actually drive it in between meetings yet but did have my computer hooked up to the XFI in the garage and was looking at parameters, not sure how to upload any logs so they don’t come out all encrypted but some things look funky.

Set in hi boost mode on the controller, flex fuel mode enabled with E70 or so, actual A/F at IDLE was 11.7, FP Corr% 99.2, MAP reading 53 kPa, spark BTDC was fluctuating between 35* and 38-39*

With foot on the brake and giving it some gas up to 1700-2000 RPMs O2 correction was 5.5% spark BTDC 37.75

Anything stand out there? Running kinda like shit

 

[Mr.Spool]

This is all kinda funky because I don’t know all how things have been setup. Something carboned up could definitely be it. Haven’t had a chance to actually drive it in between meetings yet but did have my computer hooked up to the XFI in the garage and was looking at parameters, not sure how to upload any logs so they don’t come out all encrypted but some things look funky.

Set in hi boost mode on the controller, flex fuel mode enabled with E70 or so, actual A/F at IDLE was 11.7, FP Corr% 99.2, MAP reading 53 kPa, spark BTDC was fluctuating between 35* and 38-39*

With foot on the brake and giving it some gas up to 1700-2000 RPMs O2 correction was 5.5% spark BTDC 37.75

Anything stand out there? Running kinda like shit

If its loading up with fuel the plugs could have fouled out.
Put a fresh it and look at the tune.

 

[REISJSR]

Plugs are ok, pulled all and found slight red residue from previous octane booster use, I know, dumb. Tried to upload multiple file types and they are either too large or not supported so best I could do is a screenshot, got it to stall while pulling into garage after driving. Slight blip on pedal and it fell flat and died.

Drove 2 miles after warmup, At idle IAC was 65 MAP was between 48 and 50, Fuel PSI was 71, I tried my best to watch it but did not see fuel move at all, just driving total timing showed 35-36, At another time at idle was able to snap a picture total timing 31 and TPS% 007.

Anything look crazy out of place?

 

[Mr. Michael]

Hey everyone, went to the track last weekend

How did it run ET wise?

 

[6gunn]

Fuel pressure 71 at idle? Your first post states fuel pressure isn't an issue. Were you watching it while driving or just at idle? Try lowering it to 43 or so and monitor fuel pressure while driving. I notice it's not showing in the log. Also, make sure it's rising 1:1 with boost. The correction to maintain the target AFR must be crazy with 71 base FP.

 

[Pronto]

You're running e70? Don't know what is recommended for that but you should not need 99.9% fuel correction at idle. Idle speed is too low as well. You need someone that is versed in e85 with XFI. I would start with that link in post 8 unless someone here offers to help. You should also get a fuel pressure transducer hooked up to measure you fp since it's reading 0. If you do have a fp transducer then something is wrong there too.

 

[6gunn]

Good eye Pronto. 99.2% it's a miracle that it's able to maintain a 11.7 AFR.
OP, it'd be a good idea to check the oils condition. It might have thinned out with gas.

 

[REISJSR]

How did it run ET wise?

Crappy 7.7 @97 in the 1/8th

 

[REISJSR]

Fuel pressure 71 at idle? Your first post states fuel pressure isn't an issue. Were you watching it while driving or just at idle? Try lowering it to 43 or so and monitor fuel pressure while driving. I notice it's not showing in the log. Also, make sure it's rising 1:1 with boost. The correction to maintain the target AFR must be crazy with 71 base FP.

 

[REISJSR]

I have no idea where it’s getting that the fuel and oil pressure are the exact same at 71 psi, I was watching driving and idle and neither moves at all.

I have no idea how to adjust on this thing to be honest