*RX007*

iTrader: (4)

After accumulating 1500 miles on my new rebuild I decided to start pushing the car to wot and noticed my turbos aren't functioning perfectly like before, my boost pattern now is 10-5-10 I regain full boost at about 5500-6000 rpms. As stated the system was working perfectly prior to the rebuild, both pressure and vacuum chambers aren't leaking when connected to my mityvac. and I have the viton check valves. My thought now is the Charge control valve might be opening slowly seeing as I eventually get full boost. here is a video of me applying pressure to the B port on the valve, after I pump it up it bleeds out and returns to the open position. it will only stay closed if I keep applying pressure, is this the proper way it is suppose to function? I don't believe it should bleed out but I haven't found a definitive answer.



here is a video of applying vacuum to chamber A, it remains pulled in until I release the vacuum.



Any input is appreciated!

arghx

iTrader: (3)

The charge control valve is normally open. Chamber B always receives pressure (unless you are not in boost). There's not much to Chamber B. Chamber A is controlled by the charge control solenoid. Before transition, the vacuum works with the pressure in chamber B to keep it closed. After transition, the pressure on chamber B is supposed to equalize/overcome the pressure on chamber A to open it.

I have not personally tested it, but it would not surprise me if chamber B is vented (bleeds off air). If it weren't vented, the valve would be stuck open wouldn't it? A lot if internal wastegate actuators have a small bleed in them. The wastegate on the 87-91 turbos are like that. They intentionally leak.

gracer7-rx7

iTrader: (16)

I had a similar issue after a new motor and turbos. Couldn't figure it out. Took it to Rotorsports in Santa Clara and let him deal with it. He got it working better than it ever has.

*RX007*

iTrader: (4)

hmm, ok thanks Raymond, it is a very weird issue seeing as I achieve full boost, it just takes a while to get there... I don't know where to look, the actuator rods are the proper lengnth, the pressure and vac chambers don't leak, the charge relief valve works, viton check valves are in place as are newer silicon hoses...

Maybe someone who has tested it can chime in?

Gracer7- Rotorsports didn't happen to tell you what the issue was did they?

*RX007*

iTrader: (4)

anyone think the pettit CCV would possibly fix this?

limepro

iTrader: (2)

If yours is sluggish then yes of course it would.

*RX007*

iTrader: (4)

my boost is sluggish, I dont know if what is going on in my videos is normal

gracer7-rx7

iTrader: (16)

Turbo control solenoid (the one in the rat's nest) vac lines and a couple of other mis-routed lines but I haven't fully checked it out.

*RX007*

iTrader: (4)

hmm ok thanks, can any one confirm the if the CCV is working properly from the videos?

*RX007*

iTrader: (4)

Just went through the whole system today... All the solenoids were working flawlessly, so that was kinda frustrating, I tested all the actuators and they work great, and submerged the two tanks in water, no bubbles. put everything back together and its slightly improved, it seems more responsive but the pattern is still 10-5-10, so now my only guess it the CCV may be moving slowly...

93stockfd

iTrader: (4)

I had the same symptoms after I replaced my engine a couple of years ago. I my case I broke a nipple off of the Vacuum Turbo Control solenoid…it’s the one mounted under the UIM on LIM just above the air valve…I bought a used one and installed it without testing. The turbo control solenoid acts as a check valve till activated and it was letting vacuum bleed out of the vacuum reserve.

There are two control circuits that operate the Charge Control Valve, one vacuum and one pressure. The Charge relief-charge control & turbo control are tied together.
Hook your MityVac to the line that “Y’s” to the vacuum reserve. A vacuum should be pulled after several pumps and hold without bleeding off. Pull the line off of the charge relief valve and make sure it “pops” closed. I realize you have tested this already but this is where I found my problem.

The pressure for the pressure circuit on the charge control valve doesn’t come from the pressure tank …it comes from the piping between the charge control valve and the secondary turbo, the charge control valve needs to see secondary boost to be pushed open The nipple for the pressure line is next to where the charge relief valve attaches. The pressure circuit goes from the nipple to a pipe that goes through the LIM then to the charge control and charge relief solenoids.

One might also want to check the three vacuum lines that are on the back side of the UIM next to the firewall, one could have pulled off while reinstalling the UIM.


rph