sctRota

iTrader: (2)

I'm not sure what's up here but recently I am getting an odd issue where my injector duty is never passing 50% in boost unless in neutral where it will hit 70% or so if I step on it hard.

I currently have 550 primaries and 850 secondaries freshly cleaned by RC injectors and have all been flowing correctly.

I swapped another set of injectors off my spare Intakes and same thing.

Second issue I have is unstable boost. I have a set of bnr stage 2's that have been working perfecto since day one of rebuilding them, till I started to hear the wastegate opening way too early. Funny thing is, it happens once in a while but is very noticeable due to the 14-10-14 pattern dropping to 10-5-8

I also replace my twins with a set of 99 specs due to being paranoid that I might need to inspect the BNR's for anything out of ordinary...


My build is pretty simple.
13b streetport
Ported wastegate (99 spec twins)
Blitz fmic
Highflow cat
Stock injectors
3 inch dp
Power FC

sctRota

iTrader: (2)

UPDATE: Fixed boost issue!!! turns out my blue and orange solenoids were flipped ahaa

Steady 12psi now except I still have the low injector duty cycles still.... Could it be the ground on the engine or a faulty injector?

arghx

iTrader: (3)

is it running leaner than you want it to run when under boost?

Snook

iTrader: (12)

What was the duty cycle before?

sctRota

iTrader: (2)

Sorry for late update guys. Way away from internets ahaha

My boost issue is back again :/

arghx, no it runs in the 13-8-14.5 range in both in boost and in the "bad boosting spot"
Snook, I used to get 80-95% duty WHEN my boost was working

I get solid 12psi till 4k and then it just drops to 2psi after a very unstable transition.

when free revving in neutral , I get 3.6psi and 70-75% duty cycles.

Snook

iTrader: (12)

I think everyone is confused because you have two issues at once, inconsistent boost and lower duty cycles.

So boost before was 14 psi with 85% duty cycle. Now you are at 12 psi all the way to redline and 50% duty cycle? This is not correct and too low if so, I'd guess it should be 75ish


Please spell out those details. Sounds fishy, I'm not sure how the reading for duty cycles operaties but I would be careful boosting for your motors safety until you figure it out.

sctRota

iTrader: (2)

Sorry let me clarify entirely now

These are my current problems:

1.) Duty cycles never exceed 50% unless in N
2.) After 4K, boost drops from 14psi to 2 psi
3.) When second turbo cuts out via 2.) issue, exhaust changes tone to a sound that reminds me of an open wastegate.
Motor is not leaning out at all and has steady 13-14afr

I am wondering if the duty cycles are low because the second turbo is cutting off.

Snook

iTrader: (12)

haha yes if you have 2psi boost instead of 14 you are probably losing over 150 rear wheel hp so I could see how a 50% duty cycle seems normal.

Figure out the boost issue. I'm not familiar with the solenoids and actuators enough to pinpoint the problem. The fact that the problem went away and came back shows you that a solenoid or actuator is sticking. They tend to do that on anything above stock boost, especially when they're 20 years old.

Well at least it sounds like it'll be a real cheap fix.

sctRota

iTrader: (2)

Yea, I figured so about the duty cycle issue. I have been trying to track down any leaks or issues with lines and see no problems atm. All the lines were replaced with tight fitting high temp lines. (Not silicone). Perhaps the two green dudes have reached their time. I have a spare set in my storage that I shall try tomorrow.

tbh, this is the first time I have ever had a vac/ solenoid related issue on my car baha. I solve all the locals but cannot find mine!

Snook

iTrader: (12)

I assume you have an intake and catback also?

I have the same mods but with a catless midpipe and intake and catback. Good to know I can turn the boost to 14 without replacing the injectors. Guess I just need a retune and no other mods. I also have a supra TT pump. Have you dynoed your car at 14psi? Are both or either the bnr ii and 99 spec higher flowing than stock turbos?

sctRota

iTrader: (2)

I have an ARC box and a full 3inch exhaust with a straight through highflow cat. I have tuned it to been running 14 pounds for 4 years now and never had an issue on stock injectors with pre 99's, 99's and BNR stage 2's with premix of course. I ran 1300's just to lower the duty cycles but never really got to see how they work on the track as I was back overseas in Korea and Japan again. After this problem occured with the duty and boost, I Figured that there must've been a problem with the 1300's so I removed them and went back to my old setup with IMO didn't solve the problem but was much smoother than the 1300's for some reason?

Stock pump and injectors are still good for 350whp and I don't like the supra pump as it gets hot REALLY fast (High amperage). I dynoed just around 350whp last year and it ad been very consistent. I drive pretty easy on the public roads and don't beat on it and simply just maintain it over and over ahah. I find that the BNR Stage 2's are the best upgrade with the 99 specs right beside em. Never had boost creep, and power is always very reliable and easy to control in corners.

Seems like my two green solenoid vac lines aren't fitting properly, they seem too loose compared to the way they fit on my rats nest. I will investigate this today and get back to you asap.

Snook

iTrader: (12)

straight through high flow cat? Did you gut the high flow cat or are you saying it flows well?

are you running the same tune for stock, 99 and BNR stage 2 twins? You have a wideband to confirm air fuel I guess? If you did it for 4 years my guess is your car is tuned just fine, or you would have known in 4 days rather.

I heard that the larger secondaries arent as smooth, you can feel the transition when they come on. I had 850s and 1600s in my last car but I just don't remember, it was such a differently driving car all together to notice injector differences.

Are you saying you believe your car wouldn't have the health it does without the premix due to the higher than stock boost levels?

What problems do you imagine the supra tt fuel pump could cause, by getting hotter than the stock fuel pump? draw more from the battery?

Good luck with the fix!

nismosilvia270r

iTrader: (5)

I would put my money on the Turbo Control Solenoid, located behind the two green dudes. I got a new one and installed it away from the exhaust/LIM. Then I rerouted the hoses off the old one to the new one. I left the old solenoid under the UIM. Boost transition problem fixed.

sctRota

iTrader: (2)

Two green solenoids are not the issue. tested and holds vacuum and does not leak etc.

Turbo Control Solenoid eh? I have a spare rats nets that I will take it off of right now. but would really be the cause my secondary turbo creating 0.30 (3.6psi) issue?

CRV seems to be holding up well under a vac test too. and all the connectors are placed correctly

EDIT: Changed the Turbo Control Solenoid, no dice. Same issue..

Snook

iTrader: (12)

you mention it happens sometimes, couldnt it be your solenoids sticking sometimes so that they may pass inspection now but maybe not forever?

sctRota

iTrader: (2)

Well, I just replaced them all and still the same issue. Non were sticking before and now I replaced all of them. My turbo pre spool actuator isn't moving though. It seems stuck in the middle?

Snook

iTrader: (12)

That sounds about right, any way to fix it?

sctRota

iTrader: (2)

The duty cycles are directly related to the lack of boost pressure so I am not concerned about the readings I am getting till I figure out the boost issue.
I double checked the arm and how the actuator is operating and it is working as it should and carries the same resistance as the FD I have to compare to atm.

I am really confused now because I can almost 100% assure to myself that the wastegate is opening up at 4k and dropping the boost. OR something to do with the second turbo system that I cannot see. I know the turbo is fine because I pulled the downpipe and checked the hotside fins for damage and saw nothing.

This cannot be a vac leak as I have tested the system and have found zero leaks. I want to solve this issue before I go single turbo just for peace of mind. It drives me crazy to know that this sequential problem is causing this.

sctRota

iTrader: (2)

Boost is getting more solid. Now I start to loose boost at 6.k and the duty cycles have gone up in respect to the higher rpm + boost levels as I hoped to. (This was after I reset the arm on the prespool door)


I'm pulling the UIM today and putting my hyper grounding kit in the case that the solenoids aren't having power to open/close all the time.

Heading to the track today where it will be safer for me to test and experiment. Testing all the secondary controls today with another Tee-line and boost gauge test.

FD3S2005

iTrader: (11)

I had a similar setup and issue when i had my brns s3 and it happened rarely, but i at one point after i got on it then cruised for a little id down shifted and wot, the exhaust note sounded diff, like the wastegate was open, and i could see the boost didnt really build.. never looked at the inj duty when it happened now that i think about it.. always wondered what it was, thought it was just the wastegate flap maybe sticking open after it gets really hot?

sctRota

iTrader: (2)

K I'm back again. I was crazy busy with life again -_-

Injector duty is STILL not passing 50%. Really confused now as I am not making any progress on this issue other than jumping around from sensors and vac lines that are already setup correctly.

I did a compression test on the engine just for peace of mind and I have ballpark 110 on all faces which makes me real happy to know.

I am wondering if the PFC secondary drivers are toast and its causing the secondaries not to go online. The issue with that logic is that I thought that if the secondaries do not fire, it would create a "hesitation" that should be extremely noticeable.

I want to try strapping the wastegate shut and going for a small test run but I worry if the secondaries aren't firing and will damage the engine in a lean out situation. The thing that confuses me is that the car was PERFECT before I pulled the engine to rebuild. I am not sure what exactly is going on and if the PFC has something to do with this fuel and boost issue. My solenoids are brand new and still have the boost issue. Wastegate and prespool both work as I swapped them with the other FD in the shop to test.

I am wondering again if this is a wiring issue, ecu problem, or simply the twins just being a little bitch and not wanting to function correctly. I might sell the twins and get a single turbo but I prefer to solve one thing before jumping across to another thing.