missing under boost

[Cobra80]

My car just started missing under boost in 4th gear or higher. 1-3 is fine. I changed the plugs, but it is still doing it. I am assumung it is a coil going bad. Is there a way to figure out which one it is without waiting for the computer to pick it up, which it has not yet done.

 

[ModularFan]

My car just started missing under boost in 4th gear or higher. 1-3 is fine. I changed the plugs, but it is still doing it. I am assumung it is a coil going bad. Is there a way to figure out which one it is without waiting for the computer to pick it up, which it has not yet done.

have you tried pulling one of the coils out to see if it changes the ideal.

 

[03cobra#694]

What plugs and gap?

 

[Cobra80]

I have NGK tr6 .32 gap, the person who owned it before me had some auto lite race plugs with a .55 gap, so i am sure the coils have been worked over. Should I just get a set of after maket coils? the car only has 49k on it.

 

[Cobra80]

any sugestions?

 

[SLEEPERSTATUS]

have you done the boost bypass mod?

 

[Cobra80]

Not that i know of, i bought the car not to long ago

 

[SLEEPERSTATUS]

Not that i know of, i bought the car not to long ago

check it out 03-04 Mustang Cobra ZERO Dollar Boost Bypass How To

 

[Cobra80]

this would make much more since than a plug going out because i can actualy hear the charger stop and start. Thank you I will check it out!

 

[Cobra80]

I recently had the car tuned by PSI Motorsports, they should have bypassed the need for this kit correct? Maybe they did not and i can swap it to test it. Others say that you should not do it due to over heating the blower etc.

 

[03cobra#694]

I recently had the car tuned by PSI Motorsports, they should have bypassed the need for this kit correct? Maybe they did not and i can swap it to test it. Others say that you should not do it due to over heating the blower etc.

Don`t do it.This quoted from 96stanggt
''The bypass is designed to allow the blower to bypass the air from going through the rotors when you're not in boost. You want that to happen, it keeps your blower from getting too hot. The tuner can do it the proper way which is disable in when you go WOT so it doesn't open and leak boost, but allow it to open when you're not WOT.''

 

[SLEEPERSTATUS]

the boost bypass mod is bad brad?

 

[03cobra#694]

the boost bypass mod is bad brad?

YUP,Builds up too much heat.Instead of bleeding off the boost in non-needed boost conditions,it`s creating pressure all the time.This the best I can explain it Anthony.

Read through this entire link on the boost bypass
http://www.stangshiftergaskets.com/2003_2004faqs.htm#_Toc35092406

 

[SLEEPERSTATUS]

YUP,Builds up too much heat.Instead of bleeding off the boost in non-needed boost conditions,it`s creating pressure all the time.This the best I can explain it Anthony.

Read through this entire link on the boost bypass
Terminator FAQs

:uh oh:thanks brad for the info i was going to do that this weekend

 

[Cobra80]

this was the coil, it runs great now

 

[Jomo1994z71]

this was the coil, it runs great now

Thanks for coming back to thread to tell us what it was...
How did you figure out which coil it was?

 

[Cobra80]

I just bought 2 new ones and swaped #1 and #2 then took it out put it under a load in 4th gear, that did not fix it so swaped them to #3 and #4 and that was it, no more missing under a load.

 

[TVSCobra]

no misfire faults?