PCM-Diagnostics Port - HELP
Thread Starter
Teching In
Joined: Jun 2005
Posts: 4
Likes: 0
PCM-Diagnostics Port - HELP Does anyone recognize this style port for the PCM?
Can this be tuned at a local hop, would they have the equipment?
There are only three wires hooked up to the Port. Is this Send/Receive/Ground?
Setup:
'97 LT1 in '89 Silverado
T56
'92 style computer - all emissions equipment removed
running open loop system - No Mass air
Have Ready to install:
new harness - SAME PORT CONNECTOR!!!
'95 style computer mail order tune for sequential injection - Mass air
also have the stock '97 computer
Should I mess with this setup or start with new OBD1/OBD11 connector?
I need some assistence, trying to pass emissions check and was thinking of taking it to a local shop to have the air/fuel ratio adjusted - it spits unburned fuel out of the pipes.....
Can this be tuned at a local hop, would they have the equipment?
There are only three wires hooked up to the Port. Is this Send/Receive/Ground?
Setup:
'97 LT1 in '89 Silverado
T56
'92 style computer - all emissions equipment removed
running open loop system - No Mass air
Have Ready to install:
new harness - SAME PORT CONNECTOR!!!
'95 style computer mail order tune for sequential injection - Mass air
also have the stock '97 computer
Should I mess with this setup or start with new OBD1/OBD11 connector?
I need some assistence, trying to pass emissions check and was thinking of taking it to a local shop to have the air/fuel ratio adjusted - it spits unburned fuel out of the pipes.....
FormerVendor
Joined: Apr 2007
Posts: 165
Likes: 0
From: Seattle, WA
That is the OBD-I ALDL style port GM used prior to 1996, although some OBD-I cars had an OBD-II style port prior to 1996, even though they were OBD-I. 1995 F-body cars had an OBD-II style connector, and I understand 1994 Y-body cars had an OBD-II style connector.
If your shop can tune OBD-I LT1s, and everything is wired up to your PCM correctly, then they should be able to help you.
If you decide to run your 1997 LT1 computer you will need to switch to an OBD-II style connector and wire it to the PCM correctly. Also, be aware that GM changed knock sensors in 1996. You will need a knock sensor from a 1996 or newer LT1 if you decide to switch to the 1997 PCM.
If your shop can tune OBD-I LT1s, and everything is wired up to your PCM correctly, then they should be able to help you.
If you decide to run your 1997 LT1 computer you will need to switch to an OBD-II style connector and wire it to the PCM correctly. Also, be aware that GM changed knock sensors in 1996. You will need a knock sensor from a 1996 or newer LT1 if you decide to switch to the 1997 PCM.
