Issues with ECM?

I have an 01 Sport, It is running like crap (missin, and when i get to about 2000 rpm to 3000 rpm it halfway good, but at 3000 rpm it just gases and quites like vroom vroom vroom, like im hittin the gas to the floor and letting off really quick).

now i replaced the plugs, replaced the coil pack strip(wireless ignition), and cleaned the fuel injectors, and i compression tested all six cylinders and they checked out good and even(so no valvetrain issues).

When i took it in (before injector clean) the mechanic told me to try cleanin the injectors (so i did) and then he said that hes seen xj's ECM's go bad because they get water in them and short/screw it up.

i am completely dumbfounded and am looking for help and any ideas.

My next thing that i am thinkin of doin is trying to find a new computer at a junkyard or on Ebay. (good idea or no)

thanks alot for any help folks

I see nothing in your post about error codes?
I doubt it's the ECM, those usually work or don't.

So what OBDII codes do you have? Whats your fuel pressure?

oh sorrry cylinder 5 misfire, cylinder 6 misfire and multiple misfire

kmanxj5050 said:

oh sorrry cylinder 5 misfire, cylinder 6 misfire and multiple misfire

Click to expand...

Still not an indication that the ECM is going bad... Lots of other things will cause this problem....

Check the connectors on the injectors... and the coil packs for tightness and oxidation on the contacts....

Clean the Throttlebody and make sure to remove the sensors... before cleaning thoroughly.....
Pay special attention to the the MAP sensor sensing ports...; this controls what the ECM senses for Manifold Absolute Pressure and what fuel pulse is delivered to the fuel injectors....

so the map sensor could be bad because i cleaned the throttle body out good with carb cleaner

kmanxj5050 said:

so the map sensor could be bad because i cleaned the throttle body out good with carb cleaner

Click to expand...

You would get a bad Map sensor code if it was.
I would check your fuel pressure, the ECM can't do that.

Low pressure or plugged fuel filter = lean mixture and misfire in all cylinders.

kmanxj5050 said:

so the map sensor could be bad because i cleaned the throttle body out good with carb cleaner

Click to expand...

Most throttlebodies have a coating inside the throat which is supposed to decrease dirt build up due to static when air flows across the surface of the metal. Factory recommends the use of Throttlebody cleaner and not carb cleaner....TB cleaner is sensor safe; carb cleaner is not.

Just because the MAP sensor does not throw a CEL by way of the ECM; does not mean the sensing port(s) isnt dirty....

how do i check fuel pressure?

and are the map sensor ports the two holes on each side of the throttle body?

if so they are nasty, and will the carb cleaner mess them up?

i didnt really clean those ports much cuz i didnt know what they were lol

There is a cap on the fuel injector rail that has a bicycle (schraeder) valve where you can screw on a pressure guage to check pressure when pumping up and during operation....

Generally I when I clean the TB; I remove ALL the sensors (MAP,TPS and IAC) and do a thorough cleaning of all the ports. Not that much more work to ensure good operation of the TB.

The MAP sensor is held onto the TB with two screws and has a small rubber hose that slips onto a 3/16" nipple to sense manifold pressure.

ok yeah i used that to let the pressure out before pulling the injectors.

im just takin it in tommorow becase i dont have time and have to go on a road trip with it this weekend and it needs to be fixed (i hate given in to the damn repair shops)