New Intake, Possible Fuel Cut?

[SleepyGST]

Hey guys, I realize there are millions of threads about this, but I can honestly say i didn't find another thread the same as this, but I don't really have a whole lot of time right now to just search for too long, so any help is greatly appreciated!
So i purchased a new intake and got it installed, everythings tight, all the lines are in the correct spot. I went to take a run with it, and it sounded and felt great until I got on it a little bit and I hit a wall and when I got back my parents said that they heard a huge pop. I have not done a boost leak test cause I'm confused as to what the problem is in the first place. My mod list is up to date. Sorry for such a novice question, but any help is greatly appreciated!!

 

[grothe3297venge]

I have this same problem when i go WOT at about 4.5k RPM its like boom..
My mods are Greddy rs bov,injen intake,EVOIII 16g@15 psi, tublar hearders, Greddy exhaust, and FMIC with full piping, boost/narrowband gagues. Car drives fine idles fine brand new intake filter new ALT.

I would suggest to upgrade your fuel pump also.

^^^^just noticed Wes said the same thing

 

[We're on Boost]

Here are some comments made by donniekak in a similar thread about a 2g, a couple days ago. I think these comments are correct:

Fuel cut is triggered by the ecu seeing over a certain hertz from the maf. When you burn EPROM chips, tune with link, tuner pro, or flash cable, you have to raise the airflow cap in the ecu, or you will hit fuel cut.

Maf over run is a different problem. It is caused by a 1g maf not being able to read over 30lbs/min, or a 2 g maf being pushed over 50lbs/min. It causes erratic afrs, and engine damaging lean spikes. It can be detected by looking at the raw hz signal from the maf, and it becoming erratic. It does not feel like hitting a brick wall, like fuel cut.

When upgrading the fuel system, you either trick the ecu into seeing lower airflow(safc/maft), or reprogram the ecu to control the larger injectors, and removing/raising the airflow cap.

BTW, the OP's quick fix was to lower boost to 13 psi, which he said took care of it. This was a 98 gsx.

 

[Nutty-GST]

What do you guys think a safe boost level is for no cut on the e16g. Because hitting the cut scares the dookie outta me . when it happens i park the car hug it and say sorry

 

[SleepyGST]

You sure you are not overboosting the turbo? If it's not a boost leak I would look into your wastegate and boost controller (even the stock one) to make sure everything is hooked up correctly. Do the BLT first though as I think it would be difficult to overboost a t25 (i think i saw you mention that was your turbo).

Yes I'm still on the t25, and like you said i think it would be tough to overboost it seeing as it becomes inefficient at 15psi, and my boost gauge is staying at 11psi when im WOT. I just bought everything i need to do a BLT and I'm going to do that tomorrow and tell all of you about the swiss cheese I have for a force induction system.

 

[SleepyGST]

Update: After doing a BLT i found a pretty hefty leak coming from my intercooler inlet. It seems as if the owner before me bottomed out or somthing and smushed the bottom of the inlet inwards and now theres a big leak. I'm going to see if I round the inlet out again and get the piping to seal properly and BLT again from there. PROGRESS!

 

[96awd16g]

Update: After doing a BLT i found a pretty hefty leak coming from my intercooler inlet. It seems as if the owner before me bottomed out or somthing and smushed the bottom of the inlet inwards and now theres a big leak. I'm going to see if I round the inlet out again and get the piping to seal properly and BLT again from there. PROGRESS!

Def sounds like your problem there!

To nutty-gst, I wouldn't run over 13-14 til you can log and/or tune. Do you have a boost gauge and are sure that the 16g isn't boost creeping over 4k rpm? I'm willing to bet it is. At least my 16g with exhaust would creep from 12-13 psi up to 16-17 psi in a hurry and that most definitely caused fuel cut. Porting solved my issue, can hold steady boost all day now!

 

[SleepyGST]

So I fixed that leak by using a pipe expander to round it back out, and then using a high compression hose clamp and now I have no leaks at all. I went out on a drive and it did it again, but only this time it wasn't as bad. As a matter of fact, it wasnt anywhere near as bad so I'm not convinced anymore that its fuel cut. I'm thinking it may have been the beginning of more of a sputter, but I didn't wanna keep going WOT. So with that said, do you think it's something like plugs or wires?

Well if it was that bad inside the fuel filter, I suppose it is possible that your fuel injectors are partly clogged. Did it look like the filter was torn or letting stuff through to the "clean" side?QUOTE]

Sorry I missed this question, but now that you say that there was all sorts of nasty stuff pouring out each end, and now that I feel as if my problem isn't fuel cut, I'm thinking that I either have a lack of spark or fuel causing a sputter at high rpm's. I pick up some fuel injector cleaner today in hopes of improving flow to handle the higher rpm's. What do you guys think?

 

[We're on Boost]

.... So with that said, do you think it's something like plugs or wires?

Well if it was that bad inside the fuel filter, I suppose it is possible that your fuel injectors are partly clogged. Did it look like the filter was torn or letting stuff through to the "clean" side?QUOTE]
I pick up some fuel injector cleaner today in hopes of improving flow to handle the higher rpm's. What do you guys think?

I think it could be plugs.
It could be wires too, do you think the wires on it are the original ones? I don't really know how good the original wires were on these cars - I've never had them. The wires I show in my profile have been great. Hey whaddya know, they aren't in my profile. I'll get em in there.
The injector thing seems very possible too. I don't know if fuel injector cleaner will do it but worth a try. The thing is, because of the apparently hemorraging condition of the fuel filter, there could be paper fibers in there or some other kind of nasty sediment or dirt that doesn't dissolve in injector cleaner. To actually take the injectors out and have them cleaned by a shop that does it right could be kind of a pain, especially if that isn't even what's wrong.
This is where some logging capability comes in handy. If you could log the voltage from your stock narrow band O2 sensor and also log the MAF Hz, you could figure out some things. Like, you would be able to tell if the A/F is going lean just as the stumble hits (O2 voltage going to 0) and you could tell if you are getting into fuel cut territory (MAF Hz getting to that level). It should be easy to find out what MAF Hz causes fuel cut in the 2g ecu. Hey you'll have 30 posts pretty soon. Somebody in the "tuning and engine management" tech section would know that number I'm sure.
Do you have a fancy multi-meter by any chance? I mean one that measures frequency?
Is your downpipe the stock one?

My plug wires are the blue NGK wires. They don't cost much and you can buy them all day long exact fit for your car from Amazon.com.
For your car NGK ME77 $52 from Amazon.

Anyway, try new spark plugs first - cheap and easy!

 

[SleepyGST]

yeah i tossed some fuel injector cleaner in there just to try, it obviously can't hurt, but idk we will see i guess!! but yeah when you say theres probably a lot of stuff in there beyond the cleaner's cabability, i totally believe that. haha

but as to logging and for the multimeter, i don't have my own but i do have access. my uncle and family mechanic have all sorts of gizmos lying around and would be more than willing to help me out. my family mechanic actually has his own diagnoser, i found out. not exactly sure what you call them, sorry, but it's the hand-held that plugs in under the dash. so maybe that could help me out!

as far as my wire situation, i bought my car at a dealer about a year ago and he stuck a heavy chunk of money into maintainance and the wires were mentioned, but you never know, because something as simple as the fuel filter hasn't been changed in 15 years! haha i think what i'll do before spending any money, is go to my family mechanic and try diagnosing and go from there.

thanks for all the help, its very much appreciated!!

oh and yeah you're right, 30 posts IS comin up soon

 

[We're on Boost]

Yep, now that you are armed with more information than you had before, and have fixed the boost leak, and know what the condition of the fuel filter was, I do think the best idea is to go to the family mechanic. And as far as gathering info as you drive by logging or having more gages, probably a boost gage would be a good idea so you can check to see if your boost is somehow way more or way less than stock.

 

[Nutty-GST]

@96awd16g...My boost holds fine does not go past 15 maybe some times moves down to 14 And yeah i got a boost gauge

 

[SleepyGST]

Alright guys, I'm reviving my thread from quite a while ago. I've had several more things done, and still havent figured this problem out so I'm just looking for more advice, but I don't expect it to be fixed over a keyboard.

So after thinking is was fuel cut to then just a simple top end sputter, I replaced my plugs with NGK Bpr6es' and replaced my wires with the NGK Blue's. I still didn't get rid of my problem, so I SeaFoamed it for the heck of it and the car felt healthier, but still not cured. brought it to my family mechanic and had him fix some things and check my compression and spark which both came out great. He took it for a spin, and confirmed that it is indeed fuel cut by telling me that it is in fact electronically shutting down for the split second. I told him the only way it could be hitting fuel cut on my near-stock set up is if there was a boost leak. so I handed him my tester, told him to pump it up to at least 20psi on my boost gauge and he fixed every leak that was in it.

So, after fuel filter, plugs, wires, spark test, compression test, SeaFoam, no boost leaks, and a walbro 190, I still can't go WOT. Any ideas on why I'm still hitting fuel cut?

 

[Passnu2]

sorry if I missed, but is your fuel pump new?

 

[SleepyGST]

Yup just installed last week

 

[gsxeclipse97]

Clean your maf it will make the car do all kinds of wonky things if its can't read airflow correctly.

 

[We're on Boost]

I don't think you ever said whether you are still on the stock downpipe, or an aftermarket one.

 

[SleepyGST]

Sorry, I'm on the stock downpipe yet. My boost gauge reads a steady 13-14 pounds. When I'm accelerating, I can go very high in the rpm's no problem if I'm mid-throttle, but if I go full throttle it cuts out at 4500-5000. I don't know if this helps, but before all this, my battery died and when I replaced it my idle has been shakey ever since. I didn't think anything of it at first because I know it has to figure itself back out, but its easily been a year. It doesn't seem like a vaccuum leak because I've experienced that before, but just seems like my IAC can't figure out where it wants to be. Also, on cold starts before the car is at running temp, the car kind of has a sputter-like acceleration and all of a sudden the boost will just slam in. I was actually posting on a thread about that somewhere else that other people were experiencing it, but it was never figured out. Not trying to change the topic of the thread, I just wanted to throw some more info in to try to help.

 

[SleepyGST]

Decided to run seafoam again just for kicks, found a nice leak between the manifold and turbo so could also be affecting O2 readings, but wot operation doesnt read that...im stumped guys!

 

[handsome_black]

This leak is before the front O2 sensor?

 

[SleepyGST]

Yup! Pours out where the manifold meets the turbo.

 

[SleepyGST]

I decided to do another BLT with soapy water after my mechanic claimed to have absolutely no leaks, and found my BOV's gasket was leaking, and all for injector seals were having a bubble bath. I'll report results once leaks are fixed.

 

[TSImuchforyou]

yeah i was thinking maybe bov was leaking but hope you can get it fixed with injector seals and bov gasket if not maybe bov is just bad?

 

[SleepyGST]

Forgot to mention that I found a small leak in the plastic portion of my stock uicp. The leak is in the seams or whatever in the middle. Should I gorilla glue that hole shut or melt it together with a soldering iron? Any other ideas? The hole is very very small, but a leak nonetheless.

 

[spdyshowcar]

Id try to find a new pipe gluing it or melting it back together could just cause a bigger leak down the road if anything it could be a temporary fix until you get a new pipe.

 

[SleepyGST]

So I changed all four injector seals and replaced my bov gasket, did another boost leak test to find not one bubble anywhere in the entire system. I took it out for a drive and once im at 4500-5000 at 15lbs I still hit fuel cut. I got all the way through 2nd but cut out in 3rd. One thing I did notice was the inside of coil #2 was all beat up and black, but im hitting fuel cut not bucking...guys my patience is running thin and my blood is boiling. Im absolutely stumped, I need your guys' help to restore my love for my car because im about to divorce it right about now.