So my 03 evo with 73k miles recently starting running strange... it has a rough idle and all acceleration seems to have gone away(well respectively, still way faster than my old celica lol). It no longer pulls hard even at full boost. The mods I have done are a 3 inch turbo back, short ram intake, exidy stage 2 clutch, and an AEM wideband that I installed recently so that I can start tuning the car.

The check engine light starting coming on frequently several months before the signifigant power loss. I hooked the car up to my laptop and found that it was the P0300 misfire code. After clearing it, the code will come back within 20-50 miles typically.

I logged a few runs and found that the car is detecting up to 20 counts of knock and pulling about 7 or more degrees of timing, plus its running rich. This would seem to be the source of the power loss.

At this point I'm not sure how to go about diagnosing this and fix it. I already replaced the spark plugs and found that it didnt have any effect. Tomorrow I'll be doing a compression test. Any other suggestions would be much appreciated. I'm new to diagnosing problems like this.

 

is it tuned?

 

No at this point I have done no tuning. Just several logged runs to see whats going on.

 

what gap did you set them at? have you changed your coil packs at the factory interval? yes they have them its in your owners book in the service interval section. something like 60k miles. what rom ID do you have? if its the one it came with you might need an update.

 

^^^^^^start here

 

Any updates? My '03 is doing this too, now. No tune, exhaust, intake, newish (15k mi.) COP, new plugs. Possibly fuel filter or injectors? Also, won't hold over 15 psi.
Help, PLEASE!!!

 

Just a random suggestion... I am currently using power sports tuning equipment for my car which requires minimum customary tuning work but at the same time yields very high efficiency without any hassle. I have also witnessed the employment of such tuning equipment on evo cars. When compared to that of other evo cars employing other tuning equipment and standalone ecu's, the performance is miles away in terms of speed, fuel and engine durability..

 

my turbo lancer is doing the samething so I am actually curious on the situation