aoc007

iTrader: (5)

Hey so my turbos work pretty well but most of the time just before passing through 5000 rpm the car bucks because there's a loss and sudden regaining of power, I'm thinking this is either the Charge Control Valve or an inadequate grounding issue. Anybody have experience with this happening? Thanks

setup:
stock series 6 twins
stock rebuild
power fc
twin power
550/1300
v-mount
dp, mp, cb
pullies

gracer7-rx7

iTrader: (16)

Wow. Your car is running again? Congrats.

What is your boost pattern like?

aoc007

iTrader: (5)

Haha yeah it's been awhile, I hadn't started it for two years, I changed the battery and it cranked right up in less than a second I was impressed! And I decided to hold off on my single turbo motor, just want to drive it to sevenstock and do some trackdays on the twins

I'll have to pay closer attention but I think the pattern is correct, just a bit inconsistent because I have a midpipe and stock wastegate. So 12-10-12.

aoc007

iTrader: (5)

Ok I did some more testing today, boost pattern seems to be 11-6-13. I assume this is due to the creep as my boost control is set to 12. And that's from my Defi gauge which always seems to read I think a psi higher than the boost controller even though theyre teed on the same nipple. And importantly this hesitation I have seems to occur about 4800-5200 rpm, after the transition, not every time and it's like the car looses power for a second then instantly regains it. I know that my compression is a bit low and I may have a stuck side seal and my primary turbo leaks oil and they both seem tired but this seems like it might be electrical possibly due to the insufficient stock grounding? My battery is relocated to the bin and attached directly to the starter to power the engine harness and grounded below the bin. I will try putting another ground on the ecu.

serbRX7

iTrader: (9)

i had same problem it was solenoid valve...

try this - if you have boost controler take it out (unhook the vacumm lines and hook them up to stock locations)

on the wastgate you will have two vacumm lines - take off the one thats on the right side of the wastgate.... and cap the wastgate niple - ( cut the vacum line and put a bolt in it will work )

you car should only boost 8 psi at wastgate and you car wont be bucking anymore or creep

and after this test...if you dont have anymore off thos problems ...just chang your solenoids

aoc007

iTrader: (5)

Ok, so which solenoid did it end up being for you? Thanks

serbRX7

iTrader: (9)

for me it was the one - labeled in diagram with [ I ]



but it might be more then one

did you do the test

Speed of light

iTrader: (8)

I experienced a problem like this once, and it turned out that the fuel map was really rich after the transition resulting in a similar symptom; as if it were laying down momentarily. Took out fuel there and it was fine.

Note that Solenoid "I" is the waste-gate control.

aoc007

iTrader: (5)

Hm I don't think it would be that solenoid since I have a boost controller with it's own.

Did some more testing today, it appears as though right at the transition the boost doesn't ramp up smoothly but rather slams on real quick, may be due to the midpipe with unported wastegate? I will do some poking around, want to check the charge control valve, charge relief and associated systems.

serbRX7

iTrader: (9)

yea check everthing....as i sayed it could be more then one thing

i had full 3" exhaust no cat

i also had boost controler that was making my boost patern bad and creep

your boost pattern is really bad

i just needed the car to drive
so i did what i told you....it shouldnt take you more then 5 min to do... take it for a drive reprt back

i drove it like that for about a year as i just whent singl turbo after that and took all that stuff out

it will stay flat at 8psi insted of 11-6-13 turbos will still work sequentially

arghx

iTrader: (3)

How is your boost controller hooked up? Is it controlling both precontrol and wastegate? Or do you have the factory precontrol

aoc007

iTrader: (5)

It controls both.

TRWeiss1

iTrader: (20)

I experienced a similar problem when I still had the twins. In my case, the issue was a leaking fuel injector. This is an issue that just started happening for you, I take it? By saying that it happens between 4800 and 5200, and is intermittent, suggests either an injector or the leading coil. The reason I say that is because either one of these issues will cause intermittent problems, as I have had both happen to me more than once.

That being said, I vote for either a leaky fuel injector (or injectors), or a failing leading coil. Also, verify that the harness running to your coils is good. Mine was shot, and was in need of being replaced. FWIW, I was running the HKS Twin Power as well when I had this problem...

Jdmster

Thanks SERBRX7! It works for me, But i only get 5psi of boost , my car has been bucking like a bronco lately from 3k rpm and above randomly. Although, i still have the bucking problem, driveability has increased!

1QWIK7

iTrader: (33)

So from the diagram, you're saying take off the green hose from the wastegate and cap the other side??

serbRX7

iTrader: (9)

replace wastegate it should be 8psi

whats the condition of your turbo how much miles on it

serbRX7

iTrader: (9)

just take the green hose from the right side of the wastgate and cap that wastgate niple...

the one on the left stays conected....

seandizzie

iTrader: (1)

What are you a/f ratios doing? Rich spot in the map maybe?

1QWIK7

iTrader: (33)

Yeah but then what about the hose itself? Plug that as well?

Also what would be the result If the wastegate nipple was left uncapped? Could that cause overboost?

serbRX7

iTrader: (9)

Yeah but then what about the hose itself? Plug that as well?

there is no need for that as the selenoid wont be controling the wastgate anymore

just use tight silicon line with bolt and ziptie


Also what would be the result If the wastegate nipple was left uncapped? Could that cause overboost?

yea...wastgate would not open as it need to build presure to open

wastgate control solenoid raises boost by relieving air pressure from wastgate.. so by caping that niple you will only make the boost at your wastgat spring presure

if you still have problems after this i would change out all the solenoids as you are all ready in there...i think you can get them for a good price from one of the vendors

(E) (F) (H) (I) (J)

serbRX7

iTrader: (9)

also if you are on the stock ecu and you did bunch of upgrades

that might be throwing off your ECU and causing this problem

most times this happens right at turbo transition

car bucks and then burst of power

going to PFC ecu and a tune would be one way around it... but that would be a project...

so chang out solenoids and return your car to stock as much as posible


------------------------------------------------


if you are on PFC check you tune
1300cc injectors are known to go bad

Jdmster

Well... I bought a JDM Series 7 motor, so i assume its low mileage. I'll report back, if i solve this issue. By the way, I did a auto to manual swap retaining my auto harness and ecu, Hold light is flashing and i have 2 Engine codes which are, AWS & Purge solenoid. I have a notorious bucking problem, saving up to get a PFC.

1QWIK7

iTrader: (33)

Yeah recently i had been experiencing overboost. At first i thought it was ignition breakup because i would get flat spots at around 5k.

Then i started to look at my boost gauge and noticed it was going way past 10psi.

I decided to look into the turbo area for unhooked/missing vacuum lines and saw the wastegate nipple was left free.

Maybe the cap was broken off and i didnt know about it. Im non seq but i never had this problem in the past.

Im on the stock ecu with the stock cat so i was wondering why im overboosting like this.

Anyway i capped that nipple and im gonna go for a drive today to see if that helped.

Thanks for the advice man.

serbRX7

iTrader: (9)

i think you were hitting fuel cut from over boosting

try to take some pic of your setup

ok....i think your vacuum line burst or poped off just conect it back up from that wastgate niple to solenoid [ I ] as shown in the diagram...http://www.fd3s.net/turbosystem.jpg
as your solenoid is probably ok

1QWIK7

iTrader: (33)

yep!!! That certainly was the problem. A missing cap from the wastegate nipple. Now I get a rock solid 7-8psi.

But now my car feels slow LOL.

If I wanna get a boost controller again, would I leave that wg nipple capped?

I'm gonna get a simple bc this time. Grimspeed sells a simple Manual one for 80 bucks.

Thanks again for the advice man.