So I got my car tuned about a month ago. I was leaving a car meet yesterday when the car started to "stutter" real bad(under heavy load). Its making boost, drives fine under light throttle, sounds fine just under heavier throttle it will lose all power and the check engine light jumps on. The "stutter" is real violent and feels like all power is lost when it happens, not just boost. Thats why im thinking its a fuel issue(fuel pump or pump relay) and not just a boost leak. Im taking it to my local shop today, but was wondering if anyone had any suggestions on what they think it might be or if anyone has had any similar issues.

Car is tuned on 93 octane on 27-28 PSI. Mods in signature. All help is greatly appreciated!!!

 

What pump are you running?

 

Factory fuel pump

 

Any Ideas? Can anyone help a brother out?

 

Have you checked for boost leaks?

 

Have you changed the black stock fuel pump relay to the new blue one?

 

Hmmmm no I haven't. Is this a common problem with the Evo X?

 

Huge issue, I believe there's a stickied thread about it in the fourms...the black relays fail due to poor design and cause bad lean issues, some tuners near me won't tune cars on the black relays for safety.

 

https://www.evolutionm.net/forums/sh...d.php?t=571202

 

So it turns out 1 of my recently installed NGK Spark plugs(installed a month ago) had an issue. The sleeve around the diode broke loose and was sliding down and cutting the spark off. Just thankful it was a cheap and easy fix.

Heres some pics so you guys can see what exactly the issue was.

 

theres lots of info on this issue. Back your tune off a bit, youre probably detonating. Is your check engine light set to flash on knock?

 

^^^ if your knocking parts of your plugs loose you have a detonation problem--need a retune before you buy a motor.

 

I do not have my check engine light set to show when knocking but my accessport shows that I dont have a problem in knocking. Is it possible that it may have just been a plug with a manufacturer defect? If you can see my signature with my list of parts, Im making 352 to the wheels on a dynojet. The shop that tuned it is suppose to be one of the best local shops for tuning. Not sure if there is a direct corralation between the power put down and a "safe" tune. But I see people with similar set ups making more power. Thanks for the help guys!

 

Make sure the plugs are gapped correctly.. I was robbed off 20hp on the dyno in my last car because over time the plug gap increased

 

You could keep thinking that nothing is wrong or take other's words here.
One bad batch of gas @ 28 PSI could spell D-E-T-O-N-A-T-I-O-N.