Is there a possibility that a PCM could accept a tune but still be bad?
10-25-2009, 08:44 AM
#1
Teching In
Thread Starter
iTrader: (22)
Join Date: Apr 2007
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
Is there a possibility that a PCM could accept a tune but still be bad? I have a PCM that I sent off to get VATS removed and all the necessary things done to run a swapped LS1 into my 1987 silverado. I sent it in and they sent it back to me saying everything went good in programing the tune but I still can't get the truck started. Everything has been triple checked, wiring harness etc. Is there a possibility that a PCM could accept a tune but still be bad?
Thanks for the help.
Thanks for the help.
10-25-2009, 09:45 AM
#3
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes
on
6 Posts
Could have bad elements such as the drivers for
injectors / coils, or even be missing stuff like the
IAC stepper controls (PCMs for electric throttle
can be pinout identical, but the IAC pins are open)
if you got an incompatible PCM for the motor hdwr.
Then you have the anti-theft, the outboard relays
for fuel pump and such, etc.
You need to peel off another layer and start looking
at fuel pressure during cranking, injector coil activity,
spark (use an old-school timing light to detect) etc.
Since it's a swap you have to be sure you have the
grounds that the motor needs to return the signals
and injector / coil currents and so on, as well. These
mess psople up when they get left unhooked on
motor work, even in stock type setups.
injectors / coils, or even be missing stuff like the
IAC stepper controls (PCMs for electric throttle
can be pinout identical, but the IAC pins are open)
if you got an incompatible PCM for the motor hdwr.
Then you have the anti-theft, the outboard relays
for fuel pump and such, etc.
You need to peel off another layer and start looking
at fuel pressure during cranking, injector coil activity,
spark (use an old-school timing light to detect) etc.
Since it's a swap you have to be sure you have the
grounds that the motor needs to return the signals
and injector / coil currents and so on, as well. These
mess psople up when they get left unhooked on
motor work, even in stock type setups.