hi, I need some help with my 1998 Accord LX, F23a engine, automatic. I recently put a used engine in, and after putting everything back together, I discovered it will only run when my OBD II code reader is plugged in. If the reader is not plugged in, I can't get it out of park, and nothing happens when I turn the key. When i plug the reader back in, everything is fine. If I unplug the reader when the car is running, it dies. Any help would be greatly appreciated.

 

What year/make/model accord did the replacement engine come from? Are you using the original PCM?

 

the engine came from Attarco, and the tag said it came from a 1998 Accord. I am using the original PCM, and using the original intake & exhaust manifolds, and all associated connectors. There were some minor differences in intake manifolds & throttle bodies and a different oil pressure sensor.

 

Recheck all of the ground connections. 98 is a little newer than what I'm use to but I have spent hours trying to understanding a no start issue to realize I missed a ground or loose ground. I'm assuming the code reader is giving the ECM the ground connection it needs/wants.

 

You say it's an F23A engine, but you don't say F23A1, F23A4, or F23A5 - those are the three USA engines. Are you in another country?

F23A (without a number) might be a JDM engine? Some sensors are different.

Look at the serial # stamped into the engine block. First line says F23A1 (or whatever). Second line is the serial #. What exactly does the first line say? And what's the FIRST DIGIT of the block serial #?
first digit 1 = 1998 (first year the F23Axx engines were available)
first digit 2 = 1999
etc...

 

I am in California, and thanks for your response. My old engine was an F23A1, and the new one is an F23A, so it may be a JDM engine. The 1st digit is a 1. The only sensor that I did not replace on the new motor is the crank angle sensor. I used the old distributor, oil sensor, etc. Last night I started it up with the OBD reader plugged in, ran it at 3K rpm's until the fans come on to reset the PCM like the Haynes manual says, but it still died when I pulled the code reader out. I will be rechecking grounds again tonight, but it is very frustrating, because it runs great.

 

I think that this is a problem with the immobilizer system in the car. The PCM has to recognize the key's signal. I can't remember how to reprogram key(s).

Have you tried another key?

Does anything strange happen with the green key light? The owner's manual should be able to tell you what is normal vs problem with the key light.

 

He used his original PCM, so that should already accept his key. Immobilizer problems come when you use the PCM from the donor car & you don't have any keys from the donor car.

 

The immobilizer is about the only thing that makes sense with the symptoms he has. Can't get the car out of park, nothing happens when he turns the key. I just thought that maybe having the battery disconnected may have erased the system memory on the PCM.

Another item that can cause strange problems is a security system.

 

Aftermarket alarm - that's a good idea. I've had the battery out of our 98 Accord, and that wasn't a problem for the immobilizer.

I thought(?) the immobilizer doesn't interlock the starter. Just the spark & fuel.