done EVERYTHING still boost SPIKE!!?!?

[J95GST]

i have, run the car with just down pipe, i shorten the hoses to the MBC
checked them to see if there hooked up right and it spikes really bad,
i can get on it in 1st and 2nd spikes to 25 in second but falls to like 20 then spikes to 30 in 3rd gear and i have to get off of it, bc it just hits fuel shut off or somthing, it will do that in 3 4 and 5 what can i do to fix this some one maybe send a link of how to check my waste gate and fix the flapper or whatever it is???
thanks

 

[Sean485]

What kind of boost controller is it? Did you try just running a line to the wg, bypassing the mbc, and seeing if it still spikes?

 

[J95GST]

its just a mbc i got off ebay,
no i havnt tryed bypassing the mbc what do i do ???

 

[Sean485]

Take the line that normally runs to the source port (bottom) of the mbc and run it to the nipple on the wastegate, it will only run minimum boost but if it doesn't spike you know the problem is the boost controller itself. If it still spikes then you need to look into the wg flapper sticking, etc.

 

[J95GST]

okayy i did that,
it runs better i can run all five gears out and hits 15 in first and falls to 11 then second hits 15 and falls to 11 and third hits bout 16 and falls to 12, does that mean my Mbc is bad???
before when it was spike to 30 in third i had it turned all the way down????
im running just a down pipe and i just had a check engen light come on is that bc i dont have to rear o2 sensor in its not gonna hurt anything right??
alright get back to me

is it my wast gate or my mbc?????

 

[xcz504d]

Sounds like a combination of your wastegate not opening up and a cheap MBC... Your MBC might not be letting enough pressure through fast enough, even with it all the way open, that could be because its faulty or just sucks, either way, the pressure on one side of the mbc takes to long to equal the pressure on the opposite side...

Also if your waste gate isnt at fault and the arm isnt sticking, it could be your boost control solenoid going bad.

 

[Sean485]

The small spiking you are getting with the bypassed mbc sounds like normal behavior for the t-25, I would invest in a good mbc (I have the joe P. and it works well) that has the correct spring and ball in it rather than just the cheapest one the seller on ebay could find that may or may not be the right size/strength/length.

 

[J95GST]

The small spiking you are getting with the bypassed mbc sounds like normal behavior for the t-25, I would invest in a good mbc (I have the joe P. and it works well) that has the correct spring and ball in it rather than just the cheapest one the seller on ebay could find that may or may not be the right size/strength/length.

cool man could you send me a link where i could find a good mbc for sale???

 

[Sean485]

http://www.dsmtuners.com/parts/default.php?cPath=2_138_30&osCsid=6e8a30df9ae95e364e9e4fdb9433c02a