dschmittie1

iTrader: (64)

Ok so here is the full story. The car is a 01 Firehawk. Forged 347 PT88 turbo and a Th400. 2 bar OS and 80lb injectors.

I have had the car up and running like this for about 4 months now and have been slowly fine tuning the car. I have been running with no O2 sensors because I have having some minor issues.

So the big Problem comes after a trip to the track last week. I ended up tossing my Alternator belt during my pass and Drove back to the pits and loaded the car up to go home. It did kill the battery. I bought the car home and charged the battery back up and replaced the belt.

Now. the car starts up and idles great. But as soon as I start driving the car my STFT go like +50 and the car goes 10.0AFR. stop driving and let it idle goes back to nice 14.7AFR. This is all with my O2 sensors disconneted

If I plug the O2 sensors in STFTs go -50 and the car goes Very lean.

I have gone in to the tune and disables LTFT and STFT and it still does this. I have gone in with the scanner and reset fuel trims.

Before the trip the the track the car was fine no issues all I know it I lost my belt and this happened.

I have taken the belt back off the car and it still does this so I know its not the alternator causing wierd issues. I have also looked to see that I have no chaffed or rubbed wires. I tihkn my next step is to remove the O2 sensor wires from the PCM connectors .

I have attached a copy of my tune and log of it acting up


Edit ok for some reason Ls1 tech will not let me post my config file PM me if you want me to send you the file

The Alchemist

iTrader: (19)

That's really weird... can you log commanded afr and see if for some odd reason it's changing?

Old Geezer

iTrader: (3)

Put it in open loop, and see what the A/F does....
Don't disconnected sensors force the pcm to limp mode? Have you gone thru the procedure for eliminating them, just not unplugging them?

dschmittie1

iTrader: (64)

I have LTFT and STFT dissabled in the PCM Not sure what else needs to be done to remove them. Also if I plug them back in the car does the complete opposite of what it does when then are unplgged. It goes Very Lean. Like I stated earlier I have been driving with them unplugged for 2 plus months and this just started all the sudden after loosing my belt.

Everyone on the HPT forum thinks I don't have my MAF codes tuned out properly so I am gonna change that and see what happens.

Old Geezer

iTrader: (3)

AIRC, if they are disabled and you plug them in, you should get no "reaction".
Tuning them out does not include unplugging them.
However, if they are unplugged, and have been driven for considerable time w/o the heaters operating, they may well be fried....
If they are in fact, still operating, and have been plugged into the opposite side of the harness..you will get funky results.

FUN, ain't it!!

dschmittie1

iTrader: (64)

I don't doubt that they are junk. Just odd that with them unplugged I see see O2 sensor voltages. intermitantly. Very odd

Frost

iTrader: (45)

You do not have STFTs disabled in the file that you posted. They are very much active.

DBC cars do not have limp mode. Having them unplugged simply forces OL.

Frost

iTrader: (45)

I just looked at the log... The reason the trims are running aggressively is that the sensors are showing 0mV. You should see 447mV (bias) with them unplugged. This looks the same to the PCM as having them hooked up to the harness but hanging in outside air.

dschmittie1

iTrader: (64)

Ok Any thoughts on what might cause this issue? bad ground or something. I am hoping not a PCM issues I have put too many in this car already.

1st PCM lost an IAC driver.
2nd I got wet inside and fried.
I sure hope this one isn't toast

Edit I think I will back the terminals out of the PCM first to make sure I don't have a wiring issue first

Frost

iTrader: (45)

I've never seen them read 0mV before... if their inputs were grounded it might be possible.

I maxed out your STFT enable table in the file above. It's full OL if it helps.

dschmittie1

iTrader: (64)

Thanks. I will give it a try either tomorrow or Saturday. It is just so hot and being in a non air conditioned shop I just lack motivation to work on the car.

dschmittie1

iTrader: (64)

Frost what Version of HPT are you running. It will not let me open the file says "index was outside the bounds of the array"

Frost

iTrader: (45)

Have had to use the beta for the last 3-4 years to be able to tune new cars.