having some running issues after putting a known good 94 LT1 long block in my 95 trans am. the 95 motor threw a rod @ 89,000 miles just starting it in the driveway one day, was just about to sell it so didn't want to tie up alot of $$$$ to fix. picked up a local 94LT1 from a camaro that was heavily sideswiped aft of the a-pillar. motor ran great and got a great price on the long block. now the TA won't stay running once it warms up, and won't restart until cooled down + check engine light comes on about a minute after it is started & fans come on immediately after starting even though motor is cool. cannot retrieve codes with my actron scanner even though the 95 is listed as OBD-II w/ 16 pin ALDL connector. didn't change any sensors or modules from the 94 motor and still has the 94 distributor on the long block. any ideas or expierience in this type of swap, as i read the 93-94 notor slightly differs from the 95-97's... specifically w/ the distributor drive gear. trying to stay on the cheap here. it seems like the ECU is searching when the car is started as the idle will slow down the rev up and then settle down again until the car gets warmed up the will stall when opening the throttle???? at a a loss without retrieving the codes and don't feel like guessing at which modules to start pulling off the 95 motor....

 

95 is OBDI, but with the OBDII connector. you have to use an obdI scan reader with the appropriate cable.

If you don't have one, but a cable for ~$80-$100 and then you can read the code with freescan or other similar software on a laptop.

 

its funny how cars that are rebuilt never run the way they used too. i had many problems mine too.