Bhogan909

iTrader: (6)

My personal car was running great and I went and put gas in it about two months ago. Left the station and the car wouldn't idle or drive for crap so I thought trash in the fuel.

It would start and run great for about 3 seconds and then the O2 millivolts would drop and it would sound like it was running on 4 cylinders and then die. Even if you gave it gas it wasn't changing anything.

Drained all the fuel and put good gas back in. Same problem. I thought maybe the diaphram on the Walbro 255 was collapsing, so I hooked up the fuel pressure guage and it showed 64 psi and wasn't dropping at all.

I started taking sensors off and removed the MAF. Once the car went speed density the car would run MUCH better. I went and bought a new 2002 LS6 MAF today which is what we tuned the car for.

Started the car and it's running, but the O2 Millivolts are reading from 007 to 029 on both O2's in my headers. The LT1's are staying -1 to -3 and LT2's are staying -5 to -7. The ST's on both sides are reading 0.

I have a code P0102 which I know is Low MAF Voltage. Could something have went wrong in the tune or is it an electrical issue. I checked the ENG SEN 20 amp fuse and it was ok.

Got any ideas? I looked and didn't see the O2's on the headers, but it was on a jackstand and not a lift so I couldn't see perfect.

Your help is GREATLY appreciated.

onfire

iTrader: (17)

Tunes don't go bad, so if it ran great on the tune for a while, something else is wrong. First thing I'd do since it's free, is exchange the rear o2's for the front o2's and see if a bad o2 is the problem.

Also, if you reset the codes, does the P0102 reset? If so, that's a big clue and probably is the problem.

Bhogan909

iTrader: (6)

That's what my first thing is to swap out the O2's. I already swapped out the MAF and it's having the same issue my old one was. When I go into Speed Density then the O2's read in the 880 to 920 range. When I plug the MAF back up the read around 030.

onfire

iTrader: (17)

That's a sign that it is a maf only problem. I would check the easy things. Remove and reinstall the pcm conection after you clean it with some WD40. Make sure all of the pins are in the connection...I had one push out of the connector one time.

Put a digital meter on the maf conenctor, key on engine off and see if it's getting a 5V feed and see if the ground is good.

If the 02's are switching when the maf is unplugged....sounds like a wiring problem.

P0102 is showing less than 10Hz and is really messing up the fuel mix.

Bhogan909

iTrader: (6)

Well I have the 3 pin to the 5 pin adapter. All the pins are in the correct places. I will clean them with WD40 tomorrow. I will check the MAF connector tomorrow and see what I find with the meter.
I'm starting to think it's the 3 pin to 5 pin connector. It's probably 6 years old now so I may need to pick a new one up. The wires are all still in the plastic wrap they came in though.

1CAMWNDR

iTrader: (21)

Yes, sounds like the adapter or some wire in the harness.
Good luck .

Bhogan909

iTrader: (6)

Well the car is still having the same issue. I can't find my volt meter or ohm tester so I can't test that. I put the original MAF back on and it was back to where I started and wouldn't run at all. Unplug the MAF and the O2's read back in the 880 to 920 range. I wish I was better with electrical stuff. I looked at the DTC page for P0102 and that's like a foreign language to me.

1CAMWNDR

iTrader: (21)

Sounds like it wants a Speed Density tune.