Friends,

I changed the carburetor of my Berlinetta to a TBI system used in 89~92 Camaros. It's works, but I am with the following problem: WinALDL only works with the ignition key ON, stopped engine. As soon engine start, WinALDL stop. The ECM is 1228746, but I tried with a 1228063 and a 1227747 too.
One curious thing, if MAP or TPS is disconnected, WinALDL comes alive... Looks like a ground problem... I did a triple check the harness. It is almost stock, I just add some wires.
I checked with scope the ALDL data signal and it is there all the time.
I have another car, a '67 SS Camaro that I change to TBI with the same components and same computer and cable works fine.
Can anyone give me help?
Thanks in advance...
Marcus

p.s. Sorry about my poor english!

 

! ALDL cable! Feeding for the interface was coming from the lamp SES...
For this reason it worked with the stopped motor and when there was some it fails of sensor!
Thank you for they listen to me!