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Discussion Starter · #1 ·
I don't know if there is a problem or not but I sure hope would like to know.

I just had a VF34 with STi inejctors installed. I took it for a testdrive and to my disappointment, it's alot slower than with a stock turbo. I don't feel ANY ooomph and it's hard to tell when the boost comes on. That's not all. In 2nd gear, I go WOT, around 4.5k, engine starts to hesitate and the rev goes up very, very slowly.
It hardly breaks 5K with the pedal down. When I accelerate slowly, it goes over 5K without any hesitation but it still feels slow.
Boost is fine and it seems like there's no leak. I have no way of knowing how the car doing though since I don't have any diagnostic tools.

I heard that it should be running very rich with bigger injectors and pump but would running rich cause this kind of problem?

My mods are Stage 0 WITHOUT Unichip(being reprogrammed), M2 turboback, Samco IC hoses, Supra pump and AEM CAI.
My Unichip's coming back next week but I want to know if the install was done right and there's nothing wrong.

Would waiting it out resolve this problem? Will ECU eventually learn the new setting and correct itself?

Doug
 

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I think you would need a lot more than just STi injectors with a VF34...
 

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Dougeefresh said:
I don't know if there is a problem or not but I sure hope would like to know.

I just had a VF34 with STi inejctors installed. I took it for a testdrive and to my disappointment, it's alot slower than with a stock turbo. I don't feel ANY ooomph and it's hard to tell when the boost comes on. That's not all. In 2nd gear, I go WOT, around 4.5k, engine starts to hesitate and the rev goes up very, very slowly.
It hardly breaks 5K with the pedal down. When I accelerate slowly, it goes over 5K without any hesitation but it still feels slow.
Boost is fine and it seems like there's no leak. I have no way of knowing how the car doing though since I don't have any diagnostic tools.

I heard that it should be running very rich with bigger injectors and pump but would running rich cause this kind of problem?

My mods are Stage 0 WITHOUT Unichip(being reprogrammed), M2 turboback, Samco IC hoses, Supra pump and AEM CAI.
My Unichip's coming back next week but I want to know if the install was done right and there's nothing wrong.

Would waiting it out resolve this problem? Will ECU eventually learn the new setting and correct itself?

Doug
Sounds very much as though you're running pig rich. See how things improve once you get the Unichip back. Right now you are experiencing the bad points of a bigger turbo (lag) but none of the good points (midrange and top-end).

Your experience is consistent with what other people have reported when running bigger injectors on the stock EMS.

-Pace
 

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Discussion Starter · #5 ·
Nexus6 said:
I think you would need a lot more than just STi injectors with a VF34...
and what would that be? I have slightly more upgraded parts than TXS Stage 4 so I believe I have pretty good supporting mods at this point.

Doug
 

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Discussion Starter · #6 ·
Re: Re: VF34 installed but some problems...

pace said:


Sounds very much as though you're running pig rich. See how things improve once you get the Unichip back. Right now you are experiencing the bad points of a bigger turbo (lag) but none of the good points (midrange and top-end).

Your experience is consistent with what other people have reported when running bigger injectors on the stock EMS.

-Pace
Yes, 'pig' rich would be a good way to describe it.
I 've heard that ECU will eventually make correction if I ride it out so I'll just keep drivign until the Unichip gets back next week.

It's darn slow now, exactly like you described, more lag, no mid+top end power :(

Oh and so far, no CEL yet.

Doug
 

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Re: Re: Re: VF34 installed but some problems...

I read (here or i-club, here I think) of someone doing the same thing. They gave the stock ecu time to learn and things got much better. No personal experience, just reiterating their post.

VV

Dougeefresh said:


Yes, 'pig' rich would be a good way to describe it.
I 've heard that ECU will eventually make correction if I ride it out so I'll just keep drivign until the Unichip gets back next week.

It's darn slow now, exactly like you described, more lag, no mid+top end power :(

Oh and so far, no CEL yet.

Doug
 

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Re: Re: Re: Re: VF34 installed but some problems...

VetteVert said:
I read (here or i-club, here I think) of someone doing the same thing. They gave the stock ecu time to learn and things got much better. No personal experience, just reiterating their post.

VV

Yeah I saw that. Man they gave that guy a hard time. I still have a feeling he would be running on the rich side, but it probably lean out the mixture enough to at least run relatively smoothly.

-Pace
 

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should have installed EGT at the same time, im willing to bet your not seeing past 700 deg celcius, the car runs 10:1 stock and adding larger injectors to that equation without any form of tune, will explain your pig richness, if you were catless id bet you would be spraying unburned fuel right out of the exhaust.

Dont balme the turbo for whats going on, personally i would have installed the turbo and used the stock injectors, and leaned it out with an afc, then when you want to run insane boost levels (above 17 psi) then the injectors are justified, but even with that turbo and mild boost levels are sufficient. I hope you specified your current configuration to turbo xs regarding your chip program, if so, you should be good (when all is installed).
 

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Discussion Starter · #11 ·
Marcolus said:
should have installed EGT at the same time, im willing to bet your not seeing past 700 deg celcius, the car runs 10:1 stock and adding larger injectors to that equation without any form of tune, will explain your pig richness, if you were catless id bet you would be spraying unburned fuel right out of the exhaust.

Dont balme the turbo for whats going on, personally i would have installed the turbo and used the stock injectors, and leaned it out with an afc, then when you want to run insane boost levels (above 17 psi) then the injectors are justified, but even with that turbo and mild boost levels are sufficient. I hope you specified your current configuration to turbo xs regarding your chip program, if so, you should be good (when all is installed).
I do have an EGT gauge and I am seeing over 840 in 3rd around 5-6k. I think the gauge is reading higher than it actually is.

I have a Stage 0 meaning it's from Vishnu. My chip has been at Shiv's for over a week now and when I called them on Friday, they said the cable connecting the chip and their equipment got severed. It looks like I am adding several more days to my Unichipless time.:(

I believe 17 psi isn't that insane. It seems most people who run VF30/VF34 are running around 16.5-17 psi and some even higher. I plan on running around that when the chip gets here.

Damnit, where's my chip! :rolleyes:

Doug
 

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Discussion Starter · #13 ·
PlatinumWRX said:
You really just CAN'T run bigger injectors on the stock ECU.

-Jim
Maybe... I haven't experienced this personally so I wouldn't know for sure.
So far, I logged about 70 miles in 4 days and I am still seeing the hesitation and loss of power around 5k. I did see a little improvement though.
I don't know how or who but I kept hearing peole saying that it will eventually smooth out... Even the guy(Adam maybe?) from Z performance said that it will even out and will take some time to do so. He mentioned even up to a thousand miles.

Doug
 

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840C?!?!?!?!?!

where did you place it and what kind of guage is it

840C is around target temp

thats sounds most unusual,
since this is a new turbo you are following the break in period, right?

personally i would pull my plugs to check the burn pattern on them and see if they are fouled or not

plus what has the weather been like?

this is why i do all of my work myself, no surprises, no clownage from someone else.

they didn't perchance reset your ecu did they?
 

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Discussion Starter · #15 ·
Marcolus said:
840C?!?!?!?!?!

where did you place it and what kind of guage is it

840C is around target temp

thats sounds most unusual,
since this is a new turbo you are following the break in period, right?

personally i would pull my plugs to check the burn pattern on them and see if they are fouled or not

plus what has the weather been like?

this is why i do all of my work myself, no surprises, no clownage from someone else.

they didn't perchance reset your ecu did they?
I have Greddy and is placed on the driver's side exhaust manifold (the round flat spot a few inched away from the engine.)

I was not pushing the turbo much since there really isn't a point of doing it at this point. I've heard mixed opinions about turbo break-in as well. What would be a correct procedure, if there is one?

Weather has been hot, hot, hot! high 90s with 10000% humidity!

If I can afford to do my own work(garage with a second car), i would love to. I need to get a house.

As far as the plugs are concered, I'll wait until the chip arrives. If that doesn't help than I'll check on them.

Doug
 

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I ran the VF30 with upgraded injectors without the Unichip (being re-programmed at TXS) and my car ran fine. Actually it ran so well I thought about leaving the Unichip out and having it re-programmed with the 310hp race map.

Oh, maybe some "food for thought". I was still running the stock fuel pump.

Carlo
 

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Dougeefresh said:


I have Greddy and is placed on the driver's side exhaust manifold (the round flat spot a few inched away from the engine.)

I was not pushing the turbo much since there really isn't a point of doing it at this point. I've heard mixed opinions about turbo break-in as well. What would be a correct procedure, if there is one?

Weather has been hot, hot, hot! high 90s with 10000% humidity!

If I can afford to do my own work(garage with a second car), i would love to. I need to get a house.

As far as the plugs are concered, I'll wait until the chip arrives. If that doesn't help than I'll check on them.

Doug
well that sounds to close, i placed the probe about 1" before the o2 sensor, right infront of the merge from both manifolds, so it could read an average of all 4

as for turbo breakin, i would say be easy the first 500 miles and start to modulate speeds/loads the next 500, change oil then have fun,

yes the weather plays a part as well

this is a most 'unusual occurence' please keep us apprised as teh situation is unfolding!
 

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Carlo said:
I ran the VF30 with upgraded injectors without the Unichip (being re-programmed at TXS) and my car ran fine. Actually it ran so well I thought about leaving the Unichip out and having it re-programmed with the 310hp race map.

Oh, maybe some "food for thought". I was still running the stock fuel pump.

Carlo
I hadn't considered the impact of running an upgraded fuel pump, but it makes sense. The ECU knows how to control the stock pump, so it can decrease both the injector pulse width and the fuel flow. Hmmm.

Thanks for the input, Carlo. Still grounded? :D

-Jim
 

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Been on good behavior so I think I'll be able to come out and play at Atco on Thursday :D

Now if I can ever finish my N2O install I'll be in good shape for the track!

Carlo
 

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Discussion Starter · #20 ·
This morning on m way to work, I decided to floor the car n 2nd. The needle swept across 5K mark with some stumble and hesitation. I let go around 5.5k and about 2 secs. later, voila! CEL. A blinking one, too.
Everything's going as suspected.:(

Doug
 
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