hello everyone, i have a 2004 Evo8 i cant boost anything over 13psi without it cutting out and back firing, i bought the car in April and all i know is that it apparently has a reflashed ecu and has a manual boost controller, it looks like the boost soleniod in plugged off, could that be the reason its cutting out? Ive owned 2 Eclipse GSX's so i get the jist of how everything works but i could push 20 psi on my GSX with the solenoid blocked off n it ran no problem, i asked my local tuner what he thinks and he said MAF is maxed out but i know these MAFs are good till around 25psi. Any help would be much appreciated.

Thanks,
Jon B

 

Sounds like a tune issue to me..
Possibly a boost leak?

 

Boost psi doesnt mean anything for the stocck maf lol you need a new tuner. Do a blt on the car first, then pull your plugs and make sure they are gapped correctly. Sounds like something ignition wise. If thats not the cause it may be boost cut. The previous owner may have flashed in a lower boost cut before selling to prevent engine damage from a possible joy rider and forgot to flash it back. If the solenoid is capped off that is not the issue. This is bypassed when installing a mbc.

 

Kinda what I thought at first except last time I checked boost cut never causes backfiring

 

Check for boost leaks. Then remove the MBC and hook everything up back to stock and see what it does. I wouldn't go above stock boost levels until you figure out the tune.

 

I had an issue similar to this and I found that the v-band clamp on my turbo between the hot side and cold side was loose and my cold side spun and was holding my wastegate open