Loose boost after shifting
 

I dont know if any of you guys have ever heard of this problem. My car is loosing boost pressure when I shift after a hard pull in the previous gear please guys this is a really agrivating problem also when i have no boost i hear a low grinding noise when i would normaly hear the turbos and if I press on the breaks then I will start to get boost again.

Replace your check valves. Also look for loose vacuum hoses.

Dave

i was having a similar problem as well... thought it was my eletrcial solenoids.. but trns out i had to replace my actuator... jus have it checked out...

i have exactly same problem from what i read and are about to fix,,,, its the turbo control actuator (the big one on the bottom of the turbos its controled by pressure and vacume).,, i beleive its basically one of the elecrical solenoids that supply the vacume or pressure.

They let the air in to the actuator when you go full boost on 2nd turbo but when you let off the gas the solenoids are supposed to switch off and let the actuator close by releasing the air (this isnt happening because the actuators are old and the pressure or vacume in the system is stronger than the electrical door withing the solenoid (roughly))

do you notice that when it happens the exaust note changes??

hey, mine does this sometimes. the exhaust note is wery different til it hits 4500, sounds a bit more fartcan like:)
but fuck it, im going single this winter

it sounds different because the turbo control actuator is still open

yes thats correct... the actuator is a rare problem to encounter, and is only seen on cars way over 150k ( mine has 176k on chassis )... i thought it was my solenoids, so i checked them out and they were opening perfectly... but it still kept happeneing even with new Efini turbos i just replaced... so i took my car to Ricks Rotary and he told me the problem...

If its your actuator Zack4173, then hopefully you can find a used one, because Mazda sells those suckers for around $700... :shocking:

Yeah the exhaust note changes and i loose so much power.

Cool guys ill have my rotary mechanic check out the actuator for me. Thanks for your help.

i have the same problem, but mine tends to rattle at low rpm's!

Check the PRESSURE SIDE turbo control (TC) solenoid on the rack. It's the one in the "E" position if I remember correctly--3rd one back from the front, I think. The solenoid in this position is problematic and will stick partially open sometimes. That inturn can hold the TCA open, allowing it to get out of sync with the rest of the turbo controls resulting in low or no boost for a period of time until the pressure drops low enogh in the control line to allow the spring in the TCA to close it.

Im Haveing The Same Problem And Some Time I Get A Strange High Pitch Whisstle To.