car breaks up underfull boost

[sherloc123]

i have a 92 talon with an evo3 jdm engine and when i get on it full boost itsort of stutters. the kid that had it before me said when he got it, it ran fine and he didnt drive it often cause he was away at school and when he came home and drove it around it started doing it. so im thinking either plugs or bad gas. any other guesses? its the jdm engine with the yellow top injectors with the 16g

 

[UndergroundR32]

Change the plugs for the hell of it. It's the easiest thing to check for and rule out if it's not the cause of the missfire. Also, my guess would be it's a boost leak problem since you said it happens when you're at full boost.
http://www.vfaq.com/mods/ICtester.html

 

[sherloc123]

the engine gets the full 11 pounds according to the old autometer gauge

 

[UndergroundR32]

Did you check around the engine bay for leaks though? Just because it builds boost doesn't mean it's leak free. Listen around for hissing noises after you reach the set boost and have someone pay attention to how quickly the psi decreses.

 

[sherloc123]

theres no leaks or any thing. its fine at lower boost but itsorta stumbles. i know what a boost leak would do

 

[UndergroundR32]

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