gen 5 swap falls on face over 3k

[msbweiland]

Been tuning my VVE tables. Tune and last log below. Laptop battery died, so I'll keep trying later. MAF disabled.

Idle, low speed drivability and acceleration from a stop is good. Throttle response could be better, but my hope is it will get more responsive as I go. It falls on its face if you increase the throttle on a hill to accelerate and it goes to about 3k before stumbling and not wanting to go after downshifting. Slow acceleration uphill is fine until you try to get into it.

Fuel pressure is 65psi at the regulator at idle. End of the log is me revving it up to about 3k. Seemed ok there, but under load it would fall on its face. Then if you let off the accel and eased into it it'll accelerate up the hill if you keep it from kicking down.

Should I keep adjusting the VVE tables? If I wasn't so new to the gen5 I'd say it's starving for fuel. What's the fuel rail pressure supposed to do under load? Tried MAF only and putting it back in Dynamic. Same result.

Any direction would be great. I'm close, almost there....




72 chevelle 5 3 l83 2017 silverado 3 with trans speed and fans 2nd fan DOD after o2 fixed VVE T.hptchevelle sd vve tune 2.hpl

[Ttmerc]

Stock engine? Look at the torque management stuff. General tab. Default trans limit etc, max those out see if it changes. Lots of stuff needs to be adjusted in the tune IMO. but try the TM stuff first

[msbweiland]

Here is after adjusting vve and maf for a couple of hours till the laptop died again. I tried playing with the torque tables first. Didn't make much difference with the falling flat. Made it very touchy at the low speeds. Put it back to stock and redid the vve and maf. Judging from the long term fuel I think I must be pretty close with that.
Still falls flat over about 40% throttle. The first spike on the log is the first occurrence on the drive. I made it happen a few times. Looks like the acc position is off from actual throttle position. Is that normal?
Shouldn't I be seeing the fuel rail pressure on the pids? I think I have the correct one selected. It's hooked up, no codes for open/high/low sensor. But it would be nice to see rail pressure. Normally that would be my first suspicion with the way its acting.
Drives great at low throttle input, idles good and starts great. I'm sure it's something simple. Taking a break to work on my 68 Ford crown vic swap till I get a better direction from someone smarter than me.
Thanks for the help!! Tune with the VVE tuning and MAF set back to normal (I think).


72 chevelle dynamic and maf enabled 11 21 21.hpl

72 chevelle vve and maf adjusted 1 11 21 21.hpt

[CamHaro]

you should try to adjust your throttle pedal, it looks very inconsistent when you try to go WOT and make sure it goes to 100% KOEO, also try repolling for the correct Fuel Rail pressure PID, I think is called "Fuel rail pressure (SAE)" and it should stay very close to your "desired fuel pressure" PID

[msbweiland]

throttle pedal shows 99.6 when fully depressed. Throttle plate doesn't show over 30%, but no throttle performance codes. Should it open completely at KOEO?

Fuel rail SAE shows 100 psi at most when revving in my shop (requested bounces around 600). On the posted log it shows the same, goes down when it loses power. But even after enabling all the fuel codes on first occurrence, I still get no low fuel rail pressure codes. You'd think if it was that far off and not just my scanner it would throw a p0089 regulator performance code. I get the same reading on my Modis, but it's latest update is for a 2015.

[msbweiland]

Another question. Will the fuel pump fail and not throw a code? I have no fuel codes and no gas in the oil from what I can tell. Only driven it about 10 miles though since putting it in. Maybe 6hrs or drive and idle to try to tune.
I?ve seen diesel systems fail and not throw a code, but if you look at the pump duty cycle % under load, it?ll be working too hard for what it?s trying to do. Usually from a high pressure oil leak or internal leak in the pump.
I don?t see a regulator in the wiring diagrams, so I assume the ecm controls pump duty cycle? Is there a way to check that I?m not seeing? Just a thought?..

[msbweiland]

We?ll, thought the hp pump might be it. Got a new one at gm. Still have the same fuel pressure readings and falls on its face. That?s not it.

[msbweiland]

Figured it out. I had inadvertently turned off the hp fuel pump control on the tune. Set it back to factory spec. Runs and starts way better now. Scary fast.
Now to redo all my vve and maf tuning!