Black01M6SS

iTrader: (3)

I have some tuning related questions so I figured I would start a thread here.


Original Post : https://ls1tech.com/forums/forced-induction/728127-drove-my-procharged-car-first-time-tonight-problems.html

Last night I was reading threw the AutoVE Tuning Tutorial. I saved the original calibrations and set up the maps as directed. I came to the part where it says to reflash the PCM then disconnect the MAF and then drive around and log the BEN map. I don't have my wideband installed yet so I didn't figure there was any point in doing all that yet but I was curious as to how it would run with the MAF unplugged so I tried it.

With the MAF unplugged it actually held idle on a cold start, much smoother than before. Today I started it up again when I got off of work and again it held idle on startup so I figured I would pull up some pids and go for a little drive. I noticed right away the stumbling I was getting around 3k rpms was gone...or almost, it did do it a few times but more around 3500-4k and not as bad.

I progressively got on it harder and harder keeping an eye on the knock retard. Only once did any at all show up and it was at 75% throttle in first gear. It went to 0.1 KR. That was the hardest I dared to get on it.

Is it alright to gas on it as long as there is no Knock Retard?

Also with the MAF unplugged I didn't get the P0300 Random Missfire code that I have been getting. The missfire pids didn't show any missfires at all so I'm wondering if it needed the MAF plugged in to calculate missfires?

Frost

iTrader: (45)

how are you compensating for boost? a 2/3 bar OS or ramping your PE table? What does your timing look like at WOT? What CR are you? Are you on a stock bottom end? How much boost?

Black01M6SS

iTrader: (3)

Most of this is answered in the other post but sorry I didn't include it. The tune that is in the PCM right now is just a mail order tune from EPP. I have no idea how they tuned it or compensated for boost. OS I'm guessing is stock 12202088 are the numbers but I don't know what they stand for. I've never gone WOT. The CR is whatever it is stock. Bottom end is stock. It is supposed to be an 8# kit. The highest I've seen from it was 5 psi at around 4500rpm. I was only on the throttle around 75% and I let off at 4500. That is the hardest I've gotten on it so far.

Frost

iTrader: (45)

Ask Bob or Jake since they are privy to what is inside of it... What did your wideband look like at 4500 under boost?

Black01M6SS

iTrader: (3)

Wideband is not hooked up yet. I'm about to send the car to the body shop for a while to get the roof repainted. Damn bubbles.... Anyway, I'll have them weld in the o2 bung for the wideband while it is there. I have the wires run but still don't have the sensor hooked up. I just couldn't resist driving it a couple times before I handed it over to them.

So any idea why I don't pick up missfires with EFI Live with the MAF unplugged?
I drove it again since my last post and the car seems to run much better with the MAF unplugged. Before any time it would hit boost it would studder/stumble now it seems to run decent. Pulls great any time I'm in the throttle. Still no WOT runs.

Frost

iTrader: (45)

You need to wait for your wideband or take this to a pro before you hurt your stock engine. A boosted engine makes a pretty silly terstbed for tuning if you aren't sure what is going on. I would be leary of getting a mail order tune that is based on a MAF and then unhooking the MAF, ESPECIALLY with no wideband. Its all a shot in the dark until you can monitor.