Can ECU be reflashed?

[DSMOCTANE]

I did an OEM motor swap in my Eclipse GS and am having trouble with the ECU running right with the new motor. Can these PCMs be reflashed?

 

[bryanwheat]

No they can't be reflashed. If you have a bone stock engine in there than you don't need to do any tuning. You need to diagnose the actual problem.

 

[1Gina2G]

on the subject of ecuflash and 420a ECUs..

would evoscan work for the 420a ecu for logging? or Mitsubishi only?

 

[Diamond Star Werks]

If you have a 420 use torque pro to log. No evoscan will not eork.

 

[dsmcurse]

How about post your problems your having in detail and maybe omeone on here can point you in the right direction

 

[DSMOCTANE]

-Well let me just say this: Since I had installed the new engine, I had a DTC showing that my timing had skipped one or more teeth. I purchased a top dead center indicator tool and discovered that my timing was DEAD on. After some extensive research, I had learned that this was a false DTC simply due to the ecu being calibrated to the first motor's timing cam/crank marks. I learned that these variables CANNOT be simply relearned by using an OBD-II scanner or disconnecting the battery. After gaining access to a DRB-III scanner, I was able to reset those two variables which eliminated the code entirely. I am wondering if there are more variables which can be relearned to accommodate the functioning of the new engine such as control of air/fuel ratio, ignition timing, and perhaps control of idle speed? I will try to gain access to the DRB-III tool and see if such options can be relearned.

 

[4G63_fiend]

What exactly are the symptoms? what makes you assume the ECU? For no reason at all will the ECU need to be "reflashed" due to a direct swap-unless you went from n/a to turbo. For tuning purposes there is a company called ECMTuning that offers a "piggyback" set-up that allows for real time monitoring and adjustments. It is a great tool but again that should not be needed for a factory setup to run correctly as stated above.

 

[DSMOCTANE]

Symptoms are cylinders #3 and #4 fouling with oily/gas drenched plugs and pistons. Cylinders #1 and #2 are burning fine with clean plugs and normal signs of clean carbon built up on the pistons. I am getting P0300 misfire DTC's and the motor is timed precisely, has great spark in each cylinder w/ new MSD ignition coil pack & wires, steady uniform compression, and we even did a leak down test which proved worthy and successful. I am wondering if the injectors are surging and dumping way too much fuel into those two cylinders. Would there be a specific DTC that would show for faulty injectors? Or is it just better to pull those puppies out and have them tested individually? Through trial and error, we have narrowed it down to either a fuel management issue or some kind of faulty computer error. The tech guy at Mitsubishi told me that the PCM for this new motor is required to run it, but that ECU was long gone before I even bought this motor. I already had to have the ECU relearned those two cam/crank variables to adjust to the new motor, so why wouldnt there be a possibility that other variables would need the reset with the Chrysler DRB-III scanner? The only other thing I can think of is a faulty bank 1 O2 sensor that sits on the header could possibly be giving a weak signal to the PCM. Gotta have so much patience with these DSM's, but man I love the car so much even though its N/A. I feel like the issue is right under my nose! Any suggestions are appreciated. I will keep everyone updated.

 

[grothe3297venge]

What exactly are the symptoms? what makes you assume the ECU? For no reason at all will the ECU need to be "reflashed" due to a direct swap-unless you went from n/a to turbo. For tuning purposes there is a company called ECMTuning that offers a "piggyback" set-up that allows for real time monitoring and adjustments. It is a great tool but again that should not be needed for a factory setup to run correctly as stated above.

Not for the 420a sorry.

Op - if you think your dumping to much fuel are you not using stock injectors or what??

 

[DSMOCTANE]

-It could be a strong possibility because the motor was boosted in a past life. The only thing we did during the rebuild to the injectors, was clean them and put brand new oem o-rings on them. I am hopefully gaining access to that DRB-III scanner just to be certain that other variables cannot be reset.

 

[Rst303]

I have yet to see a flashed 420a ecu besides standalone megaquirt , try to find out or post a injector part number so we can all see if your running the factory injectors.

 

[2gnt]

Can these PCMs be re-flashed?

Sorry they can't be re-flashed, but maybe one day:
www.neons.org • View topic - Neon PCM Reprogramming

 

[DSMOCTANE]

So I changed the upstream oxygen sensor and recalibrated the pcm to relearn the crank/cam positions and still running a bit funny. Again, the symptoms are an over abundance of fuel in cylinders #3 and #4 and appears as if they are not firing correctly. #1 and #2 are burning fine and have regular carbon deposits on the pistons and white plugs. #3 and #4 on the other hand foul plugs and it appears there is not much carbon deposit on the pistons at all. People keep telling me that my oil rings are not installed right, but why would they be fine in cylinders #1 and #2? The leak down test proved worthy, but then again how could you tell that the oil rings are dysfunctional? Might pull the injectors this weekend and have them tested. Turns out they are OEM, because we compared them side by side with the original motor's ones and have it documented in our notes and photos.

 

[H@xtGSX]

It sounds like either you have too big of injectors, your fuel pressure regulator isn't working right, or there is a restriction causing the fuel pressure to be too high. Isn't 3 and 4 injectors the first fed on the rail? If so, the excess pressure could be blown out into those cylinders, leaving 1 and 2 closer to normal... Just a theory.

 

[DSMOCTANE]

-Many fellow mechanics seem to be suggesting that my fuel pressure regulator may be stuck open or faulty. Whats a standard fuel pressure reading when you test it for the 420a? I am going to be testing the fuel pressure tomorrow with a tester. There is def an over abundance of fuel in those cylinders and I feel like your theory makes logical sense.

 

[jksmith]

No they can not be reflashed, you would hvae to replace them, atleast they are fairly east to find