Hi there everyone. Long time lurker here. Hopefully someone can shed some light on these logs.


Some History: Car ran great all summer and most of the fall. Did a hard 3rd gear pull and let out part way thru the pull and held constant pedal and the car started jerking/missing/bucking....BAD. I can consistently duplicate this behavior. #rd gear part boost hold steady at a certain pedal percent then boom car falls apart.


I listed 2 logs that I did this evening using Mitsulogger. First one I think the trouble starts at log position 35ish and continues until the end of the log at 40 percent tps. The second one was longer with a full pull or two at the beginning and then at the end of the log the trouble starts.


Another weird thing I noticed leading up to the trouble was I noticed that I was having to turn the boost up with the MBC to maintain what I was running previously. As in I was at 22 psi and tapered to about 18 at 6500ish, but started having to turn up the boost every few days to stay at an 17-18 taper.. Also noticed much more taper much earlier. I am now tapering back to 14-15 psi where before I was tapering to 17-18 at high rpm.


Mods: Full LICP and UICP, Bigger front mount, full exhaust, MBC.


I bought the car early summer and had to replace coils and plugs..car ran great all summer. I recently replaced the coils and plugs under warranty when the issue started. I was told the car was tuned at 22 psi from the previous owner and if I can get this problem fixed I will take it immediately to get a tune that I can verify.

This is an evo 9
Any and all help is much appreciated. Ian

 

Fixed. Found a hairline crack on my inter cooler that was not showing up until higher boost. I was not boost checking to a high enough pressure.