WVUSierraC3

iTrader: (2)

Hi,

I have a 69 Camaro with a LQ4/T56 combo in it, I have it all together and running, idles fine but I have a p0102 code for maf voltage too low I believe. So I hooked up a scanner too it and the maf signal doesnt change at all when I rev it in neutral and when I take it out for a ride. Also the car runs well except when I try and get on it more then 1/4 throttle, it seems like it wants to fall flat on its face. Hopefully these two things are related so I'm wondering if anyone has any suggestions. I have 12 volts to the maf, a good ground and 4 volts to the maf signal. Any suggestions please I wanna get this thing running good so I can start driving it more.

Thanks
Tom

JaYZeig

iTrader: (11)

im assuming you have this style maf i posted in my link..found this browsing online one day, and maybe you can use this as well in testing your circuits, especially your reference..maybe youve just got a junk maf if everyhting else checks out.

http://easyautodiagnostics.com/gm_ma...tic_test_1.php

bronx_peanut

Mine was doing the same thing. It ended up being the company I bought my harness from wired the MAF connector wrong.

LS1-450

iTrader: (33)

Why do you have 12v to MAF??? Sounds like you have 12v connected to the PCM out pin on the MAF. Should be ground, 5v ref from PCM & then output from MAF to PCM. 4v in may be why you have a low input code. The PCM may also be throwing the code because there's no output to the PCM. This is more likely. 4v is just about enough. Look up the schematic for your year PCM & run the MAF out to PCM connection to the corresponding number on the PCM.

WVUSierraC3

iTrader: (2)

I appreciate the help, first its a 5 pin truck maf, I'm pretty sure your supposed to have 12v to the maf via the pink wire, a ground, maf signal, iat signal and iat ground. I also went over the wiring and made sure that its all correct, which it is. I believe that the maf signal was actually like 4.8 or something like that which is in spec, but on my scanner its only reading .208 or 2.08 something like that and isn't changing or moving. The IAT is working correctly and starts about air temperature and rises with the engine warming up. I have cleaned the maf with maf cleaner, I'm wondering if the maf might be shot? I'm going to try and get the Hertz reading from the maf like was posted in the first post and hopefully that holds the key. Any more suggestions would be appreciated.

Thanks
Tom

psiconversion

iTrader: (5)

What is the pinout on your MAF connector and what year is the engine combination?

Jon
PSI

WVUSierraC3

iTrader: (2)

Jon,

I actually got the harness from you and it originally had a plug for the MAF and for the IAT, and you sent me a 5 pin pigtail for it. It's a 2002 LQ4 6.0 liter and I followed the directions that you sent me. I don't have the pinouts in front of me currently as I won't be home for a week, but as I said I followed the directions to a T and went back over them on Saturday and everything looked right.

Thanks,
Tom

WVUSierraC3

iTrader: (2)

Bumpski

psiconversion

iTrader: (5)

Ok. Give me a call today and Ill give you a few things to check.

Jon
PSI

LS1-450

iTrader: (33)

Was thinking 3 wire. Do know that the IAT sensor sends a signal to the PCM, does not receive any ref voltage, just a ground. This leaves 3 wires for the MAF. A 5v ref voltage, output to the PCM & ground. This covers all 5 wires. There does not appear to be a need for 12v anywhere. If you connected 12v to the 5v circuit, probably fried it. There should be only (1) ref voltage, 5v to the MAF. 4.8v is OK. Again, the code is just an indication of a problem. Low input could mean fried circuit 'cuz the output to the PCM is low or incorrect. 5v ref should come from the PCM to the MAF. Check wiring schematic for your year PCM for pin locations. Again, I see no requirement for 12v to any of the circuits.

WVUSierraC3

iTrader: (2)

Alright guys thank you all for your help, turns out to be a bad maf sensor. I took the sensor off of my dad's truck and put it on the car and boo ya, I'm getting maf readings, I take it out for a quick spin and no lag what so ever, so it looks like I'm gonna go back to the salvage yard and see if I can get a replacement. Once again thanks alot for all your help.

Tom