overBoost/ cutoff problem

[morpheus1]

So i did a diagnostic check the other night (paper clip in te1 to e1), and this morning, i warmed it up and took it out to get some early morning boosting in, when i noticed my boost guage needle went well over the stock +8 guage ( it seemed almost 10-11 psi or something), and my car kinda stumbled and loss the boost, now it does it every time i floor it, yesterday, boost would hold at 6.8 psi regularly when i floored it, what happened ?, and how can i get it (boost regular @ 6.8 while keeping it floored) -back to normal? :cry:
Normally: (numbers indicate boost pressure) 1-2-3-4-5-6(-)7-8 Around here.
Now it like: 1-2-3-4-5-6-7-8+()(car stumbles)
im at a loss here but is it a fuel cutoff deal?

 

[Poodles]

Yep, it's fuel cut, and it sounds like you have wastegate issues. Check the vacuum line to the wastegate.

 

[morpheus1]

Yep, it's fuel cut, and it sounds like you have wastegate issues. Check the vacuum line to the wastegate.

how do i bypass fuel cut and keep boost at a steady pressure?

 

[trydrew]

You can't bypass fuel cut (well you can, but), in this case you just want to keep it from happening. Check your wastegate vacuum line at least (and all others), and maybe check your i/c piping.

Put simple, fuel cut is just a way for the car to keep itself from overboosting too much. Normally, people try to get rid of it with BPU mods, because it gets in the way when people start tear things up and turn up boost.
Since you did nothing in the way of attempting to turn up the boost, then something is wrong, and your car is letting you know.

 

[92TealSupra]

Ahh the famous Fuel Cut Off. You could have a inter cooler piping leak or your waste gate is no opening properly, even vacuum lines that are cracked and leaking a small amount of air can cause this problem, look over everything, its Toyota's way of helping you not run to lean.

 

[jdub]

Ahh the famous Fuel Cut Off. You could have a inter cooler piping leak or your waste gate is no opening properly, even vacuum lines that are cracked and leaking a small amount of air can cause this problem, look over everything, its Toyota's way of helping you not run to lean.

It would have to be a pretty big vac line to cause boost cut on a stock motor. Most issues you see with vac leaks are at idle. A leak in the IC piping...different story. Or, a WG issue like Poodles suggested.

 

[morpheus1]

Ahh the famous Fuel Cut Off. You could have a inter cooler piping leak or your waste gate is no opening properly, even vacuum lines that are cracked and leaking a small amount of air can cause this problem, look over everything, its Toyota's way of helping you not run to lean.

i did find a hole in the vacuum line that connects the aif filter housing connect tube (main big pipe deal) that connects to the bottom of the turbocharger( ct26), well, more to the side of it, its the only vacuum line i can find that is located underneath the air filter tube, but it has about a half inch across hole in it, (im fixing it right away anyway, but i dont know if thats the main problem causing it).

 

[morpheus1]

Replaced all vacuum lines, problem was solved, i dont mind it now, i liked the extra power, so i shimmed the wastegate 3/4" in washers from the Turbo housing.
So now no leaks and still puts out around 250 hp or so with wastegate shimmed out.
CT26 is stock but keeps around 10.5 psi, pulls a lot better now