stuttering under boost, sure its not a boost leak.

[GsxEcutioner]

hi, well i guess im posting this is in the right forum. awhile back my car as hesitating for an odd reason, well i drove around and i was boosting 17 psi fine, in vacuum it doesnt stutter at all. just under boost, and has never done it before until one day. well when i WOT now at 4k and 16 psi it chugs a bit but will move up slowly. i changed the plugs and wires, but its still stuttering, before i changed them, the CEL was on. and after i changed it, it went off. uhm idk whats going on. please help. i just turned the boost down today, as far as i can go, and im still boosting 17 psi..................=/ thanks for the help
-shane

Car:1996 Eclipse GSX

Mods: ported 14b turbo, ported 2g exhaust manifold, ported o2 housing, MBC, KnN Filter, Greddy sp2 Cat Back, centerforce 2500lb clutch. and 1g bov with upper ic piping

 

[d3str0y3r]

this happened to me in the winter...we thought that the car was pulling timing because of the cold weather...turns out that my boost controller was f*cked up and i was just boosting to infinity and leaning the car out...whoops. that only cost me the entire motor.

try changing the boost controller...they are only $7-$8 and they can save you a lot of trouble.

 

[GsxEcutioner]

this happened to me in the winter...we thought that the car was pulling timing because of the cold weather...turns out that my boost controller was f*cked up and i was just boosting to infinity and leaning the car out...whoops. that only cost me the entire motor.

try changing the boost controller...they are only $7-$8 and they can save you a lot of trouble.

it just somehow messed up one day?

 

[mach4g63t]

Check your fuel system. Maybe the stock one is giving up? And if you adjusted the MBC to get lower boost and it's still running high that's definitely something you might wanna look into. If your plugs are good, your timing is good? ... I would say look into fuel maybe, but definitely check out that boost controller. Maybe it's leaking or something.

 

[My91TalonTSi]

If you've checked for the obvious like boost leaks, bad plugs or wires, I would figure out the boost control problem and turn it down. With the stock fuel system and a 14b my 1g started to run into fuel cut issues when going over 15psi with no tuning device.

Another option would be to upgrade your injectors, pump, and get a logger and tuning device if you feel your running out of fuel.

 

[GsxEcutioner]

the wierd thing is, before i was boosting 17psi all day until redline. then one day when my missfire came, and then after i replaced the plugs and wires, the boost is like this. so you guys think its the fuel? if it was fuel, wouldnt it have happend long ago?

 

[TwoLiterLaser]

What was the CEL code for? Are you sure it is a misfire? I would bet you are hitting fuel cut due to a busted boost controller or wastegate allowing it to go over 17. As far as the 17 psi, I have never had a 1G that would pull to redline with 17psi on the stock MAFS and fuel system, but that does not neccessarily mean anything.

 

[GsxEcutioner]

What was the CEL code for? Are you sure it is a misfire? I would bet you are hitting fuel cut due to a busted boost controller or wastegate allowing it to go over 17. As far as the 17 psi, I have never had a 1G that would pull to redline with 17psi on the stock MAFS and fuel system, but that does not neccessarily mean anything.

uhm the CEL came on, i wasnt sure what for, but i felt a missfire, so i changed the plugs and wires, and after an hour of driving the CEL shut off and no more misses. im thinking its either my MBC or my Turbo itself. and i have a 2g, and it did pull 17 psi til redline. what do you think?

oh yha, and when i bought the car, the previous owner said that he wasnt sure if there was an aftermarket fuel pump,and i havent opened it up to check.

 

[loveTOspeed]

uhm the CEL came on, i wasnt sure what for, but i felt a missfire, so i changed the plugs and wires, and after an hour of driving the CEL shut off and no more misses. im thinking its either my MBC or my Turbo itself. and i have a 2g, and it did pull 17 psi til redline. what do you think?

oh yha, and when i bought the car, the previous owner said that he wasnt sure if there was an aftermarket fuel pump,and i havent opened it up to check.

It's the Barometric pressure sensor. You're gonna have to buy a whole new Mass airflow sensor. That just happened to me. If you want to make sure I'm right, hook up a diagnostic plug and find out the cel code, If it's the BPS then it'll give you code 25

 

[DSMSpyder99]

i agree with check your plugs, the code that probably came up was random misfire. The same thing you are describing has happen to me a few times. That is why i regap my plugs every 3,000 miles.

 

[GsxEcutioner]

i hope it was the missfire, but it still doesnt make sense , if it were the maf, then wouldnt it still be on? and im guessing, that i still need to replace the mbc and maybe the pump?

 

[freshlane]

What did you gap the plugs 2?

 

[GsxEcutioner]

What did you gap the plugs 2?

0.028 ?

 

[GsxEcutioner]

bump*

 

[GsxEcutioner]

can this be the coil pack?