05Evolution8MR

So I've been having some issues with my 05 MR. To make a long story short and get to the point I want to replace my ECU to see if my original ECU is the issue. My car is lightly modded. It was stock when I bought it in 2006 and I then put in a fuel pump, boost controller at 21 PSI, HKS 272 cams, removed the catylitic converter and took the car to Switzer and he tuned my stock ECU on his dyno.

I'm not a "tinker-er" and I hate working on cars. I wanted the car to be dependable and yet decently quick and that's what I got. I did nothing but drive the car daily for the last 8 years with this setup.

From my forum searching it seems as though I want to first save my immobilizer code and then download my flash that Switzer did. Put in a different ECU and load this information on, correct? My question is can this be done with any USDM EVO 8 ECU from 2003-2005 or does it specifically have to be a 2005 P/N 1860A118

Thanks

detroit pistins

iTrader: (102)

What is the issue you are having? We maybe able to help save you the time of going thru this headache.

05Evolution8MR

About two months ago it started with a couple misfires or hiccups in the higher RPM range. First things first I replaced the spark plugs and no change. Then about a week later it got worse, when I would get under load and boost would get to about 15psi the car would drop two cylinders and just run way crappy. I would have to shut the car off for a few seconds, restart it and it would be fine. I could grandma drive with no problems but the second I try and boost, it would do it again.

The car sat a for a week and I replaced the spark plug wires and coil boots. Started the car up and went for a drive, now the problem got worse again. Now I couldn't even get to 15psi before it would drop two cylinders, If I just tried to drive at all, getting close to -1 vacuum to +1psi it would drop the two the cylinders. Shut the car off, restart, back to normal.

I called Kiggly and he came over, ran some scans and we tried some logs. Some readings were all over the place like 02 and air flow but other things looked normal. When the car would drop out he said the 02 sensor readings would just flatline. He found it puzzling and gave me another mass air flow sensor to try, that changed nothing. A few of his ideas were either fuel or the ECU. The ECU seems probable as this issue is not giving me a check engine light, which the ECU is not self diagnosing.


I bought a new Aeromotive fuel pump, installed that a week later, that had no change and now the problem is worse as the car sat. I can free ref in my driveway and get to about 4,000 rpm's and it will drop out, keep it from stalling and eventually over about 10 seconds the two cylinders will start running smooth again.

Then a week later I installed a new cam position sensor, no change.

So this is where I am at, I would like to try putting in a different ECU to see if my took a dump.

mrfred

iTrader: (50)

i had a very similar issue. turned out to be the exhaust cam position sensor. which cam position sensor did you replace?

i doubt its the ecu, but easy enough to swap.

have you tried swapping coils?

have you considered the crankshaft posn sensor?

05Evolution8MR

My car only has one cam position sensor as the MIVEC's have the intake and exhaust sensors correct?

I have not tried the crank sensor. As for the coils themselves I had unplugged each one while the car was idling and both reacted they way they should. That doesn't mean ones not screwing up though.

For me it seems if I can get ahold of a used ECU, change the code and plug it in I can tell right away if it's fixed. If not then I can move onto coils or other sensors and the ECU can be resold, but I can't return two new coils to mitsubishi.

But that still leaves my question about if an 8 ECU will be fine or if I apecifically need one for a 2005.