***Blackonorange's STS Turbo Build!! - Done by Speedtech Saskatoon***

blackonorange

Thanks guys !!

blackonorange

Well we couldn't find the leak, and now the engine idles at 1100 ish and I got the code lean bank 2 afr stays at 15 ish and vac is at 12 at idle I also can only boost to about 4 psi

blackonorange

And on top of that the bov don't open and the compressor surges eveytime

hindi1973

having the same problem in my customers sts 370z , we tried everything to make it boost again we even made a direct hose form the turbo to the wastegate so it can give the maximum psi of the turbo and it gave 3psi , no leaks , we made a smoke test , their was a history of a bad pcv valve which made oil come out from the exhaust ,went all the way to the intercooler,maf sensors, piping etc etc , fixed that and cleaned everything and still doesnt build boost , check engine comes back on and idle at 1100 , spoke for ben STS went step by step with a confrence call with my mechanic and it looks like the 3 port solenoid is messed up since we made a and its suppose to make a ticking noise and its not , this is the last solution if not then its a bad turbo which went bad after 1000 miles or so , although their is no smoke,shaft play or anything , so lets see what happens after changing the 3port solenoid . wish you the best .

p.s all of this took place after loads of exhaust leaks that happened and fixed them then changed tha bad place of the boost controller which was under the back bumper . since then problem after problem has been happening .

Boosted Performance

^^^If you connected the wastegate to the compressor, and the boost gauge to the IM, you will not see max boost pressure. You need to connect the lower half of the wastegate direct to the IM to see max boost pressure.


Where did yo guys get the BOV vacuum source and wastegate boost source?

If the wastegate source is right at the turbo compressor, then you will not make wastegate spring pressure for boost. This is due to pressure drop across the entire system, in this case a lot of piping. So there maybe 8psi at the compressor outlet, but only 4-5psi (or less) at the IM. The wastegate should be hooked up as close to the TB as possible.

BOV must go to the IM as it uses vacuum to open. However, if the manifold vacuum is up in the -12 in/hg, then the wastegate will not open. The spring inside it (assuming it is a Tial type BOV) is rated for vacuum, and it will not open unless the set vacuum for that spring is reached.






So with the VQ, vacuum should be in the -19 to -20in/Hg (at idle fully warmed up) and the -10psi spring is optimal. It will never open if the lowest vacuum you see is -12in/Hg.

There must be vacuum leaks present, and it would explain the high idle. Exhaust leaks will not alter the a/f ratios unless they are pre O2 sensor. In this case if the OEM sensors are used on the headers, it should not make a difference.

blackonorange

What's the 3 port solenoid ?

hindi1973

we tried all kind of ways to make the turbo build boost to the maximum by making a direct hose from wastegate to the turbo , this way should give us the maximum psi possiable of the turbo , but it also didnt , we closed the exhaust side of the wastegate to see if vents air we said it might be a bad wastegate spring but its closed and no air , the solenoid am talking about is the pcv swith
we applied 12v to the post on the PCV switch and listened for a click , their was nothing , the hose that was in the intake we pulled out and everytime we go on boost it spills alot of air/oil out side like crazy which means the crank case is getting filled with boost insted of the turbo ,

The PCV switch is grounded when the body is bolted down (Normally open)and then a 12v signal is applied when 1psi of boost is applied (switch closes) then it vents to the atmoshere through some small filter on top of the switch

i guess this is our problem , if its not then i dont know wht is the problem other than the turbo it self . i am waiting on STS BECAUSE we changed both pcv but didnt change the switch , and hoping they can send us the switch , it looks like it has 3 ports or something similar

we are not in california and i am really intersted in deleting this pcv switch thingy once and for all , i know its against some states in usa such as california , all info is appreciated in getting this switch or deleting it completely .

thanks

blackonorange

How could you be building boost in the crank case? 0_0

hindi1973

i kind of didnt understand when BEN was talkin to the mechanic about it , but when i read this thread it made sense , now i am looking to get this switch or away to cancel this headache once and for all .

STS turbo kit smoking like a chimney, ?? - LS1TECH

everything makes sense , not the same vehicle , but same kit kind of , and same issue almost .

blackonorange

My symptoms are different then that tho, mine doesn't smoke there is no oil anywhere it just idles at 1100 with vac at 11-12 and can't boost past 3

hindi1973

Just figured to share that's all

blackonorange

Car goes back in the shop today hopefully it's some thing small , did you check the intake manifold gasket?

hindi1973

yup all good , the pcv switch should make a ticking noise and its not at all , so i guess this is the problem , if not then

blackonorange

Well I dropped the car off let's see what they can find , hopefully it's minor

blackonorange

What's tb stand for?