That code is generic to one of the injectors, its pretty obvious which one you have a problem with. Maybe the next test you should do is unplug the injectors and test resistance of the injectors. Using a DVOM or ohm meter you should read somewhere around 12-16 OHMs. Dont worry too much if they are a little off due to temperature but maybe you will find #5 way out from the others?

As was mentioned earlier a simple test light can maybe help too. All injectors should have power on the same color wire to each injector (dark green/black I think) and the other wire which is a different color on each injector is grounded through the PCM for injector control/driver circuit. You can hook the test light to both injector terminals and it should blink the light when cranking or engine running (this way tests power and ground/injector driver circuits). You could also hook the test light to Batter positive side and other end to the injector control circuit wire to "blink test" and they also make noid lights for this specific test.

 

resistance are on all 6 injectors 14,5 ohm

 

just now i´m ready with the blink-test
Cylinder 1 -4 are blinking
not so cylinder 5 + 6
the test light is on but not flashing.
i checks the wires from the PCM to the injector connectors, the wires are ok.
and now ? bad PCM ?

 

If you hooked the test light up across both injector wires at the same time and #5 & 6 kept the light on then both injectors are being commanded on all the time. Since you checked the wires back to the PCM and they tested ok, that means the PCM is bad. Just make sure that you tested the circuits for short to ground, you could even unplug the PCM and see if the test light goes out, that would assure that the PCM is keeping the injector energized and faulty.

 

the last test is done.
i pull out the injectors with the fuel-rail and go to ignition.
from injector 5 + 6 comes full power fuel, the other 4 are ok.
the next step, i pull of the electrical connectors from injector 5 and 6 and go to ignition.
now are all 6 injectors ok.
fail signal from PCM ?

 

Everything is pointing towards the PCM.

 

today i plug the "new" PCM, YES
the engine runs smooth and sounds good.
only one new code: 31
EVAP canister purge solenoid i think , i check it tommorow
thanks all for the help

 

I dont know a lot about these GCs, and am pretty new to working on JEEPS but I had the exact same issues as you and replaced my ignition coil for $38.00 at AdvancedAuto and I havent had a problem since. However they have a better ignition coil for $62.99 that I am going to upgrade to as soon as I get paid. Hope that helps a little.

 

this thing makes me crazy
the engine runs great, but i can not find out the fail for the Code 31

EVAP canister purge solenoid

i found the canister but no solenoid.
i read the last days in many forums, and i read: the 94 Grand Cherokee have no solenoid.

can anyone help me to find the problem ?
the tank lock is ok