I have a 97 xj and the check engine light came on. I had the code read and it said cylinder 1 failure. It runs great. So I went to go have it checked and on the way to my mechanic it went off. That was three days ago and now it just came back on saying the same thing. Could someone help me with any ideas as to what it is.

 

If i remember correctly there isnt a "cylinder 1 failure" OBDII reading...
201 Injector #1 control circuit problem (open or shorted)
301 Misfire detected in cylinder #1.

But you could try resetting the ECU...

Pull off both battery leads, and then touch positive cable (not attached to battery) to the closest body panel, let it sit for about 30-60 minutes, hook it all back up and see if that helps...

you could also try disconnecting the CPS and seeing if that resets it. but im not sure that applies to your model year

 

Ok I will try that and let you know. Thank you very much.

 

That worked for about 30 minutes and then it popped back on. So any other ideas anyone has?

 

Post the EXACT code number. There is more than one code associated with a failure on a specific cylinder.

Spark plug, spark plug wire, distributor cap, fuel injector, internal condition of that cylinder, wiring/connectors, etc.....

 

Ok I will do that tomorrow. Thank you

 

some things to check would be your spark plugs, spark plug wires, or maybe even a dirty or leaking fuel injector.Try taking out the spark plug from cylinder 1 to see what it looks like.you might also want to check your distributor cap for cracks or wear.

 

nvm didnt see the top post

 

The code that came up is P0301

 

Cylinder 1 misfire

 

Pull off your dizzy and check the posts... clean your spark plug connection or replace wires... go from there

Sent From My Toyota Recovery Vehicle.

 

For a single cylinder misfire, I always approach it in this order.

1. Spark plug. Replace them

2. Spark plug wire. Replace them

3. Distributor cap. Replace it. Buy one with brass contacts, not aluminum. Replace rotor while you're at it.

4. Fuel injector. Swap it with the injector from another cylinder to see if the code follows to that cylinder.

5. Internal condition of that cylinder. Perform compression test. Spec compression for the 4.0 is 120-150 psi, with no more than a 30 psi variation between cylinders

 

Ok awesome guys thanks