Idle and boost issues

[MR.P]

Hello my 2jz-gte from an aristo have som problems. I had the code 22 and I changed the coolant temp sensor and the code went away. Now I have the code 42, the speed sensor. Can the speed sensor cause any problems?

Okay is it normal when you have no battery on the car and then connect the battery, start the car and have no idle? when I drive the car for a while it idles but sometimes it wont idle but when I start it again it idles again.

My car boosts like 7.3 psi (or 0.5 bar). when I reach like 4-5000 rpm the boost drops a bit. at 8000 rpm its like 4.35 psi (or 0.3 bar).

Is this the IACV? mine does not operate at all like in this video: http://www.youtube.com/watch?v=8gie3CHMlI8

I manually pulled it open but the boost was lower when I drove the car.

I also tested the ttc mod but it act the same as before.

What can the issue be? the turbos doesnt have unnormal play in the axles. Is it the second turbo who not are coming online? and what can cause that? Thanks

 

[hvyman]

How are you getting to 8k. Stock Ecu only goes to 6500.

Speed sensor won't be an issue. Your goin to lose boost on the top end especially that high as the turbos run out of breath at that rpm.

You can pull the iac open or closed? The Ecu resets it to fully open everytime you shit the engine off. You will heart a clicking noise from it as well. If you don't it's likely bad. You can also test it like the manual says.

 

[MR.P]

How are you getting to 8k. Stock Ecu only goes to 6500.

Speed sensor won't be an issue. Your goin to lose boost on the top end especially that high as the turbos run out of breath at that rpm.

You can pull the iac open or closed? The Ecu resets it to fully open everytime you shit the engine off. You will heart a clicking noise from it as well. If you don't it's likely bad. You can also test it like the manual says.

Dont know, I have a dakota digital box to the stock rpm gauge. it idles 700 rpm and and you can rev it to 8000. Maybe something with the ecu is wrong or the rpm converter.
No i opened it up and put 2 big screwdrivers to stop it from closing. but it does not move when I am revving.
isnt this the iac valve?? http://www.max-boost.co.uk/max-boost/resources/SUPRA_MKIV/Idle_air_control_valve.pdf

But the boost should not drop after 4000 rpm right? it should go to 0.8 bar ? Isnt it like the 1st turbo boost 0.5 bar and then at 4k rpm it goes to 0.8 bar when the second turbo kicks in?

 

[525gte]

Every time you unhook the battery the ecu has to re learn .. It will run and idle like crap go for like a 30 min drive should be better. Don't keep u hooking battery. And as be for speed code don't matter

 

[MR.P]

Every time you unhook the battery the ecu has to re learn .. It will run and idle like crap go for like a 30 min drive should be better. Don't keep u hooking battery. And as be for speed code don't matter

ok it sems to idle fine know But what can cause the 2nd turbo to not come online?

 

[hvyman]

are you sure its not? IF its the same in ttc and twin then its not the turbo.

 

[MR.P]

are you sure its not? IF its the same in ttc and twin then its not the turbo.

no not like in the video i linked. It doesnt move at all. It is the same in ttc so it must be something else. The vacuum hoses sems to be fine but I will check it again. Is all the vsv:s important? because You bypass 2 of them when you go ttc right?

 

[starletmunchkin]

are you ttc? sounds like you dont have something right in either the exhaust bypass valve or the reed valve. I was having the same problem, i could only get 8 psi out of it.

 

[MR.P]

are you ttc? sounds like you dont have something right in either the exhaust bypass valve or the reed valve. I was having the same problem, i could only get 8 psi out of it.

Yes I testet ttc mod and it acted the same. Did you change them or repair them? can I test them in some way?

 

[starletmunchkin]

I was having problems with my vsv solenoids, and was only getting 8 psi, i did the permanent ttc mod were i completely removed all the vsv, iacv, and manually opened the exhaust bypass valve on the y pipe near the downpipe, after this instant 15 psi on bpu. I know its the cowardly thing to do when trying to diagnose the sequential system but its a good way to find out if its a vsv,iacv,egcv issue or not.

 

[MR.P]

I solved the problem. It was the lines to the pressure tank who were in wrong place. I switched the place and it now runs great. Thanks all of you guys

 

[tlo86]

make sure you set the rpm converter to the right engine size thats what that is

 

[MR.P]

make sure you set the rpm converter to the right engine size thats what that is

Okay will do that