TK7

iTrader: (6)

today must be question day! i guess so since ive worke dall day on the car, and i think ive finally found some things wrong.


I tee'd into the TCA lines. confused about my results.


pressure:

KOKO causes it to show about 7 PSI, but instantly returns to 0. the needle just flicks to 7, and back to 0. each time after that, it flicks lower and lower(using up stored pressure?)

example

KOKO: 7,0
6,0
5,0 and so on.
should this be happening?


went for a road test with it tee'd in. at 4500rpm it shows about 10psi, and quickly falls to around 7 or so, but seems to hold that till redline.
functioning as it should, i think?



vacuum:

Tee'd in the same way. road test shows 0 psi all the time

obvisouly ive narrowed it down, and im going to check the vacuum side of everything now.

should the pressure side be flicking like that during KOKO?

TK7

iTrader: (6)

update

i took off the IM and started checking all the vacuum lines. pumped it with 15inhg and it held.

got some leads to my battery and tested the vacuum solenoid. no clicking was found. So i grabbed a spare. it clicked as it should. i pumped it full of vacuum again, and gave the solenoid voltage, and it release the held vacuum. so for a last test i cooked the solenoid at about 175 for 5 mintues, pulled it out and ran the same tests, and everything worked as it should.

so, i installed it and began to test using KOKO while the manifold was still off. I can pump it full of vacuum, and then KOKO and it releases it as it should

alright! .......or so i thought.

started doing the KOKO and looking at the TCA. same results! the rod just flicks, doenst hold anything! urrr.

this TCA was just replaced and it appears to hold pressure or vacuum if applied by my mity vac. The lines running to it, leaving the rats nest, looked fine, but i replaced them anyway, and it STILL does it!

i dont know now? me's confused? when KOKO, should i see what appears to be just a momentary realease of pressure and vacuum? its almost like the ECU sends voltage, but only for a split second?

time for a PFC?


.....help

dgeesaman

iTrader: (7)

The 7psi in the lines after 4500 isn't right. When I tee'd in I got the same pressure in the TCA line as what I just got in boost - 10psi.

The KOKO will see reducing pressure and vacuum with each cycle as it discharges the tanks. I think the KOKO should not just flick the TCA, but to be honest I'd like to check it myself on my car. I just need to tee into the TCA lines and run the KOKO test to confirm.

TK7

iTrader: (6)

^thatd be great! cause im at a loss now. i

t really seems as if the ecu is only sending voltage for a split second. that would explain why i see the TCA rod "flick" and why when KOKO, with my boost gauge in where the hose leaves the rats nest, toward the TCA, i only see it "flick" the needle.

ive got somehting like the flu now... so i cant get back out there to re-test the vacuum side. but i bet its acting the same now. just a "flick" of vacuum.


let me know what you see on your car. thanks

dgeesaman

iTrader: (7)

I think the ECU sends voltage as long as the key is in the 'on' position, but I have to check on that to be sure. It's not in the Mazda documentation.

If that is true, the flick would indicate some kind of slow leak in the solenoid or hoses running from the solenoid to the actuator. But I want to check on that.

Dave

TK7

iTrader: (6)

ok. I tee'd in to pressure and vacuum again.

pressure:

KOKO shows a flick to 7ish PSI. road test shows 10 psi at 4500rpm but it trails off to 5 psi or less by the time it gets to redline.


vacuum:

KOKO shows a flick of the needle to 15ingh. road test shows over 10ingh at 4500rpm, but it also trails off as it heads toward redline.




KOKO shows CCA closing fully and holding as long as its in the on position. the TCA has the same "flick" of the rod as it always has.

dgeesaman

iTrader: (7)

The fact that you are losing pressure/vacuum from 4500 to redline suggest that something is leaking - either the solenoids, hoses, tank.

The fact that both pressure and vacuum are leaking suggests the leak may be in the TCA itself and thus the pressure is leaking into the vacuum.

If you're using a mityvac, try applying pressure to one side of the TCA to check for a leak. It should hold up to 10psi indefinitely.

Dave

TK7

iTrader: (6)

well, it would make since for it to be the TCA if i had actually tee'd in like i should have.


but all i did was disconnect the lines leaving the rats nest and connect my boost gauge line to it.

so, doing it this way, the TCA is not even in the loop.

dgeesaman

iTrader: (7)

Ah, I see.

It's entirely possible that you have leaky check valves, hoses, or somesuch on both the vacuum and pressure sides of the circuit.

Dave

dgeesaman

iTrader: (7)

Lacking a helper, I decided that this KOKO question would be a good excuse to run the car and warm up the engine. (Sadly, the FD did not get out today in spite of the 60 deg high temp). My boost pattern is normal.

I tee'd a spare gauge into the line running from the rats nest to the vac side of the TCA. The question was whether the solenoid should stay open indefinitely, or just flick open for a moment. I set up the spare gauge gauge so I could see it from inside the car. Rev of the engine and I got 4psi in neutral according to my regular boost gauge. Then I keyed off, and keyed on. I got a brief flick of vacuum. In fact, in the quiet of my garage, I could hear the solenoids click twice, rapidly in succession.

So my conclusion is that the stock ECU just cycles the TC solenoids briefly and lets them vent, resulting in the TCA just budging and going back to its resting position. If I was really hardcore I'd go back out there and shove a pin in the ECU harness at the TC wire location and see if the electrical signal is the same way. But I'm not in the mood anymore.

Dave

TK7

iTrader: (6)

well......this is good and bad news! ha.

all this time i thought i was kinda of close because it has always flicked like that. now we know thats normal....

crap....no clue what my problem is then.

im using dales check valves, and i can pump pressure or vacuum into the respective lines and it will hold all day! :O(

but wait...so this explains my KOKO results, but what of my road tests? im seeing both pressure and vacuum trail off quickly after the initial surge at 4500rpm.

system holds as it should and both the vacuum and pressure turbo control solenoids have been tested and replaced.


i dont know.....maybe a loan and a single turbo is the only answer!

thanks dgeeseman for checking everything and answering all my questions. if you have any further ideas for my current situation, please let me know.

dgeesaman

iTrader: (7)

Well the road tests are not normal. I did the same road tests before and as long as I stayed in throttle the solenoids did not release. (They are on/off only). Whatever is in the pressure or vac chamber at the 4500 is what you should see constantly in the pressure and vacuum side of the TCA also.

When you let off the throttle you should then see the pressure/vac release back through the solenoids.

I suggest you get a tee fitting. They're like 10/$3 from mcmaster-carr. Then you have an excuse to stock up on random but cool stuff like self-adhesive silicone tape and all the fancy versions of Loc-tite. They have nice vac/pressure gauges for $20 too.

Dave