deez-nuts-77

iTrader: (8)

hi everyone im new to the site and to the rx7 world. i got a 93 about a month ago.

on with my problem. the 2nd turbo does not kick in when i am in 1st gear but when i shift to 2nd gear it will kick in. if i am driving normal and floor it while im in 2nd or 3rd gear it is a crap shoot on the 2nd turbo engaging (sometimes it will sometimes it wont) but if i let out of the gas and nail it again it usually kicks in.
the car was all stock when i got it and it had this problem then but now i have done the vaccum line upgrade and have it running in simple mode with a manual boost controler.

i think i read something about it could be the in the 2 plastic precharge tanks. i took the one off by the intake manifold and it had no leaks but i have not got to the one under the altenator yet. i was hoping someone could shed some light on the subject or point me in some sort of direction.

thanks for any help
josh

adam c

iTrader: (2)

I would start by replacing the little check valves under the black pressure tank. I think there are 3 or 4 of them?? They are notorious for causing boost issues. Be sure you place the new ones in the proper direction.

deez-nuts-77

iTrader: (8)

thanks alot for your help i will start there this weekend when i get some time.

shipdriver

iTrader: (1)

That definitely sounds like a vacuum leak. The tank under the alternator is the vacuum tank. It has a check valve on the line to the UIM. The other check valves are one the pressure side not the vacuum side. The following solenoids and associated valves use the vacuum system: Charge Control Valve, Turbo Control Valve and Charge Relief Valve- so check the those hoses, solenoids and valves. I was losing vacuum too and dgeesman here on these forums got me going in the right direction. Tearing through these systems has taught me alot in a relatively short amount of time.

deez-nuts-77

iTrader: (8)

thanks i can use all the info i can get so keep it coming if anyone has something to add. its a little nerve racking looking at all the vaccum lines right now but im sure it wont be that bad once i tear into it (ive downloaded some diagrams). im still use to DSM's where i basically only have a couple lines running the turbo but this car is alot more fun

weetbix13

the second post; Adam C is 99% spot on with your problem dude.
pressure/vacuum is stored in the the chambers to aid with boost levels/transitions - if that pressure/vacuum bleeds out of the chamber through a crapped out check valve you will find this problem.

adam c = the man on this one.
no point tearing it down, just replace the check valves.