Aristo 2JZ Swap. Will not Boost in 1st gear

1990 mk3 targa

Ok the swap has been done for about 3 weeks now. and i started to notice that 1st gear wasnt as strong as second so i focused on the boost gauge(stock boost gauge) while accelerating and it wont go above Zero. the rest of the gears are fine, pegs out 8+ psi on the gauge quiet nicley.

When i received the motor one of the VSV's was broken(one on top the motor) and i replaced it.

Besides that do you think maybe a wireing issue?
 

monster2j

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Aug 20, 2010
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mine did the same thing and i was told its normal, because the r154 transmission doesnt put enough load on the motor as does the stock automatic. i just switched to single turbo and problem solved :)
 

kneedragger85

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Sep 9, 2008
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I'm pretty sure I can at least hit 8psi in first gear. Every other gear turbo #1 hits 10psi and turbo #2 hits 14psi.

EDIT: Did you keep/replace all your vacuum lines?
 
kneedragger85;1743557 said:
I'm pretty sure I can at least hit 8psi in first gear. Every other gear turbo #1 hits 10psi and turbo #2 hits 14psi.

EDIT: Did you keep/replace all your vacuum lines?

some were kept and some were replaced that looked really bad

---------- Post added at 10:12 PM ---------- Previous post was at 10:04 PM ----------

taking it to the shop tomrrow and looking it over any suggestions would be nice
 

Dirgle

Conjurer of Boost
Mar 30, 2005
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I can definitely see more than 8 PSI in first gear. Double check all of your intercooler pipes, don't just look at them, physically try to separate them. Next in your other gears do you have the mid-range fall off point where the second turbo comes online. If not you may be trying to spool the first and second turbo at the same time. Also if your pressure tank is failing or has failed, the sequential system may not function properly if you haven't built positive pressure in the last few minutes.
 
Dirgle;1743606 said:
I can definitely see more than 8 PSI in first gear. Double check all of your intercooler pipes, don't just look at them, physically try to separate them. Next in your other gears do you have the mid-range fall off point where the second turbo comes online. If not you may be trying to spool the first and second turbo at the same time. Also if your pressure tank is failing or has failed, the sequential system may not function properly if you haven't built positive pressure in the last few minutes.

Ok il go over this today and check it out..
It seems to pick up quiet nicely when the second one comes online..like you can tell the difference when the other one does start to spool

---------- Post added at 12:07 PM ---------- Previous post was at 12:06 PM ----------

hvyman;1743608 said:
Solution. Go single. ;)

il buy the parts if you come put it on and tune it for me :)
 

te72

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Mar 26, 2006
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I wonder if this is an issue exclusive to the 2j, or the CT12B's..? Hell, I see 15-16psi in first on stock ct12a's.

Edit: What gears do you have in the differential? I have 3.73's, lots of load to be found there. :)
 

kneedragger85

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Sep 9, 2008
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Boulder, CO
te72;1743846 said:
I wonder if this is an issue exclusive to the 2j, or the CT12B's..? Hell, I see 15-16psi in first on stock ct12a's.

Edit: What gears do you have in the differential? I have 3.73's, lots of load to be found there. :)
Us JDM 2JZ guys have CT20A's, USDM twins are CT12B's.

EDIT: We're in sequential mode which the first turbo has an electronic exhaust valve that's closed off from turbo #2 under 3800ish rpm and also has an internal wastegate. Thus, turbo #1 has essentially 2 wastegates. When the transition to turbo #2 occurs, that exhaust valve is pressured open via the EGV VSV pulses which bleeds off turbo #1 exhaust energy to prespool turbo #2 and you will see a dip in boost when this occurs. Then both are online at 4k rpm. It's just the nature of the system and it's a complicated one.