Mfanto

Im new to the turbo world coming out of a 350z. I here a lot of people that have to check there vacuum lines. Where are the vacuum lines located, and to check them are you just looking for tears, and leaks? I have a 1st, and second gear, secondary turbo problem. Only once and a while my turbo will not boost up top, but it is only in 1st, and 2nd gear. The rest of the gears are perfect 10-8-9 about. I have a hks downpipe, apexi power fc, greddy exhaust, greddy smic, cold air box, hard pipes, greddy hard elbow set. Should my boost be more like 11-8-11, or am I ok. I changed my boost control selonoid, and it made my secondary boost work a lot better. What do you guys think? Should my car be making more boost, and could I tune it safely to make more boost, or would that put to much stress on the engine? Help!!

Mahjik

iTrader: (1)

There is no need to start another thread, you already have one going with troublshooting help already provided:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/boost-332367/

Majority of the vacuum lines are located under the Upper Intake Manifold (UIM). You'll need to remove that to inspect anything that has to do with the solenoids that are usually controlling most of the sequential system.

I provided you with a picture of the vacuum diagram in the last thread:

http://scuderiaciriani.com/rx7/vacuum_hose_diagram2.jpg

Once you remove the UIM, you'll see the solenoid layout as described in that picture. You need to test BOTH "Turbo Control" solenoids as they both control the Turbo Control Actuator.

There are testing/troubshooting procedures in the Factory Service Manual (FSM):

http://www.iluvmyrx7.com/3rd_gen_manuals.htm

Mfanto

why does it only happen once, and a while mahjik. I took it for a ride yesterday, and I got great boost in all gears..

Mahjik

iTrader: (1)

Solenoids can work fine when cold, and begin to fail when hot (or vice versa). Like any device, it can be "malfunctioning" and not completely "broken".

It could also be a damaged or kinked vacuum line that performs differently depending on the amount of heat the hose has absorbed.

Anyway, you'll never know until you break out the tools and start doing some real troubleshooting. There is no way to know "exactly" what is wrong with the car just typing messages, work actually has to be done to narrow the problem down.

73828793

i had a similar problem when my car was stock. if i was at a stop too long i wouldn't get boost til 3rd gear and would have to let off and floor the gas for the turbos to work. after a little searching with the good ole carb cleaner and fingers i found i had a pin hole in the vacuum line going to the vacuum chamber below the alternator. before i fixed this i would get a max secondary boost of 8-9psi when the car did decide to boost, after i fixed it i was getting 11-8-11 all day with zero problems.

73828793

this statement is dead on. your best bet is to have all the vacuum lines replaced and the solenoinds checked with a Digital Volt Meter. i once had a turbo control solenoid ohm out at 270 something when the car was at operating temperature! which was the reason why my secondary turbo was not working at all.