94 Shadow 2.5 misfiring

[veedubmechanic]

Found cyl 1/2 are not firing. Pulled plug wires off and they arc to ground but seems like they are not firing in the cylinder due to the large buildup of gas in the cylinder. I replaced the plugs, wires, cap, rotor, hall sensor and injector. After replacing the injector the car runs LOTS better but still misfires. I read codes and there is a code 12 and 27. I suppose the 27 was from the injector but I cant seem to find code 12 anywhere? Any help here?

[denisond3]

The code -12- might be different on your 94, but on the Dodge Neons from 95 onward, it meant the battery voltage had been disconnected from the computer in the last 50 times the ignition was turned on; or at least it had dropped way below 12 volts.
I had an injector that quit firing on my Neon, and got the 27 code. It turned out that I hadnt Fully Seated the wiring harness connector to the computer. It wasnt even loose 1/32", but that was enough! Seating the connector until I heard its locking tab 'click' solved the problem of the injector not firing, but the code will still be there for a few days I suppose.
If you had tried to start the car with one injector disconnected you might still get the -27-, but it shouldnt matter.

[veedubmechanic]

Checked compression
1=0
2=0
3=140
4=145

Wet test yield the same numbers... looks like its time for a head gasket booo

[demo_deven]

Also could be a siezed valve...Have the same problem on a 94 Shadow here but i'm going to smash it to bits so it doesnt matter : ) Hopr you find the problem, Deven.

[KManiac]

With Number 1 & 2 cylinders "cross-pollonating", it is definitely time pull the head. But there may be more to this problem than just the gasket. I am just two hours of work away from finishing the head job on my Shadow. You can read about it in my earlier posts.

Before you can remove the head, you will need to remove the accessory belts and timing cover to release the timing belt. Replace the timing belt if more than 90,000 miles and/or you can't remember the last replacement. The 2.5 is a non-interference engine so breaking the timing belt while driving will not damage the engine. Its just a good idea to replace what you can while you have the chance. I suggest removing the head, intake and exhaust as one unit to save time and effort. But it takes two to remove this unit from the car. Once you get the head off, take it to a machine shop for an inspection and overhaul, if needed. The head bolts are "torque to yield" style and cannot be reused. You will need new head bolts and a head overhaul gasket set.

Good luck with this project and let us know if you have any questions.

[veedubmechanic]

Guess the guy my buddy bought the car from 3 weeks prior (who was a chrysler mechanic for 20yrs??) is going to pull the head and replace the HG for free =)