po 300 code 96 sl2

[danboy]

I bought a 96 sl2 5speed with a spun rod bearing. I Had a totaled 94 sl2 for a parts car. I took the block and the crank from the 94 and put bearings and rings and went throught the head. Put it back in the car and it runs fine but I get the random misfire code. I have a friend with a hand held scaner and it showed #2 and#4 were misfireing. I swapped the coils packs from one side to the other and still 2 and four missing. I had just put a set of belden wires on my parts car a few months ago so I put them on the 96. I ran ngk plugs in the 94 so I put a new set in the 96. I also had the injectors bench cleaned and flow tested. I have driven the car a few times and it runs fine.Once in a while the check engine light will flash for 30 seconds and then go back to just on. The napa store said they can test the ign module if I bring it in. I read a service bulliten about the crank angle circuit needing to be reprogramed. They called it crank angle relearning. It has to be done with a scan tool that can write to the pcm.
If the ign module is good does anyone know if I need to take it to the dealer or if I can find a repair shop that can do it. I also put a new o2 sensor on the car. The freind of mine said he did not think the cat was pluged and the car does not drive like it is. I hate to deal with the dealer if I don't have to.
Anyone have any ideas let me know. I buy thease cars dead and fix them for my kids . It makes it a crap shoot when you can't drive the car before you start on the rebuild. Thanks Dan

[BarnOwl]

Sounds like what happened on my (now my daughter's) '96 SC2. It's a crankshaft relearn and only a dealer can do it. Considering this is a rebuild you've probably already done the normal tune up stuff. Don't go overboard and toss every part at it you can imagine like I did. I chased this thing for months and I did finally have to take it the dealer. One thing you can try to see if it's the same thing. My light would flash for a few seconds on occasion. However, if I drove at high RPMS (3500 to 4500 RPM), it would flash continuously. Here's the thread where I got it solved. It contains links where you can read the whole saga.

[ssicarman]

You may also have a problem if you did not swap all of the 96 electronics over to the 94 engine. I believe that the injectors are different largely due to the OBD 1 and OBD 2 requirements. So the safe way to go is to swap over everything.

[danboy]

Tried a guy at the local Buick dealer I know and he checked his tool and it did not cover Saturn. Went to saturn and they knew what I was talking about and perfomed the Crank sensor relearn in about ten minuites. Charged me 42.50 and sent me on my way. He looked under the hood and told me to replace the ects ,pvc valve and plug wires. He told me when the cars went to ob11 in 96 they had a lot of problems with missfire. He said the pcm needs the ohm value of the oem plug wires and plugs . He said the resistence is used in place of a cam position sensor. This made no sense to me but I bought the parts and drove away with my check engine light off. My friend at the Buick dealer told me the crank relearn procedere is very common on GM cars if the crank sensor is changed or a replacement engine.