04Z06vette

my son bought a 94 firebird LT1 that wasn't running due to water pump and subsequent opti issues. somebody had already been into the front of the engine, but they never put it all back together. old timing chain was in the trunk. he tried putting the new opti on, but couldn't get it to start. replaced ign module and injectors. if we take the timing cover back off and the dots are lined up, is it still possible that the crank is 180 out, i.e. not on the compression stroke? i read conflicting info on here. if marks are lined up, is that 6TDC or 1 TDC? sorry for the long write up.

shbox

http://shbox.com/1/cam_timing_ani.gif

If dots are lined up, it can't be wrong.

04Z06vette

Thanks. Your site has an amazing amount of info. We really appreciate it. One more question. 94 firebird, but it has the 16 pin obd2 connector. From what I was reading, they were supposed to be 12 pin in 94, or did Pontiac switch earlier? What kind of reader do we need? Can these flash codes by grounding a pin? Or can we jump ground and serial pin from 16 pin to 12 pin connectors and use and obd2 reader?

shbox

It should not have a 16 pin DLC unless someone changed it. If they did that, they might have changed the computer as well. You'll need to get the service number off the PCM. Can't flash codes past 1993.

Dirty_Bird

Is possible to have put the opti in wrong where splines arent lined up. Had this happen once and timing was 180° out

04Z06vette

False alarm. I should have got my fat **** under the dash before I spent so much time researching OBD1.5. It is actually an OBD1 connector after all. My son must not be able to count pins.