JBs93FD

I've got a 93 with 85000 miles the turbos nor the car leak anything but i have poor boost after 3500 I've checked all the vaccume lines i could look at without pulling the uim, the lines still have elasticity and none were off. the car has a 10-5-8 boost pattern, could the charge control sylonoid have took a crap, has anyone had similar problems

Sinful7

When I have that problem, it's associated with a failed check valve. Seems like a common issue - the small vacum line check valves fail with time. If you can, get into the secondary turbo range and when it's only making 8 psi, rapidly lift and reapply the throttle, see if it comes to full boost. If so, there's a failed check valve.

JBs93FD

lift all the way off and then to wot?

Sinful7

Yup, point being - If it's check valve, then lifting the throttle suddenly causes a forceful transition to vacum for the pressurized systems. If a check valve isn't operating properly, what you're doing is using air to force it closed. You don't have to take your foot of the pedal, but lift it quickly and briefly, and reapply WOT. Try it in second gear, because first is over really fast and it can be difficult/jerky to lift and slam.

JBs93FD

it did as you said, so how do i go along fixing this, i also just got my mazda repair manual if you got it refer to it.

Sinful7

Well, you can see the check valves in the diagram in the following link:



https://www.nopistons.com/forums/ind...howtopic=42957



It shows three, but the image only labels two. Anyway, these can either be replaced by OEM Mazda equipment, or there is reports of NAPA carrying suitable replacement valves. I have yet to replace mine because the problem is intermittent.

JimmyJimboJet

isn't someone on the evil forum selling viton replacement check valves? i thought i remember seeing something like this over there a while back...

Sinful7

[quote name='JimmyJimboJet' date='Apr 19 2005, 12:18 PM']isn't someone on the evil forum selling viton replacement check valves? i thought i remember seeing something like this over there a while back...


[/quote]

Yeah, actually I recall that as well.

JimmyJimboJet

[quote name='JBs93FD' date='Apr 19 2005, 11:59 AM']it did as you said, so how do i go along fixing this, i also just got my mazda repair manual if you got it refer to it.


[/quote]



here's a link to those viton check valves i was talking about...

http://www.clubrx.org/default.asp?id=8&ACT...ontent=26&mnu=8

JBs93FD

well i cant last a day without something ******* up . i got a radfiator leak and dont know where its at, there was steam comming from the front (infront of airbox) tore it down to take a look, none of the fittings are leaking but there is a puddle on top of the fans and what looks like under where they mount to on the top of the radiator and on the radiator under fans are all saturated. can the tanks get a hairline fracture and leak, is this common.