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!!

 

[WES_393]

What do you mean by new intake? Intake pipes, intake manifold, intake snorkel? Regardless, you should never assume you have no boost leaks after doing anything with the intake. If you just replaced the snorkel (MAF to turbo pipe), then make sure the MAF's electrical connector is clean and tight as well as double checking all the couplers. If everything checks out then do a BLT.

 

[SleepyGST]

Sorry I didn't specify, in your terms, the snorkel. There's also a K&N open cone filter on the end just thought I'd add. I check my MAF and it looked very clean including the electrical connector. Question about the BLT: don't BLT's usually involve taking off the air intake and using a coupler on the inlet of the turbo? This problem started when I added the air intake, so shouldn't I be testing that? One thing that I can think of is the coupler that came with the kit that connects the intake pipe to the turbo didn't have a smaller end on it so it was a little big for the turbo inlet. I had to crank the clamp pretty far before it was snug. If my problem of hitting that wall sounds like a boost leak symptom, I can almost guarantee that it's because of that coupler.

Thank you for the reply as well!

 

[SleepyGST]

Sorry I didn't specify, in your terms, the snorkel. There's also a K&N open cone filter on the end just thought I'd add. I check my MAF and it looked very clean including the electrical connector. Question about the BLT: don't BLT's usually involve taking off the air intake and using a coupler on the inlet of the turbo? This problem started when I added the air intake, so shouldn't I be testing that? One thing that I can think of is the coupler that came with the kit that connects the intake pipe to the turbo didn't have a smaller end on it so it was a little big for the turbo inlet. I had to crank the clamp pretty far before it was snug. If my problem of hitting that wall sounds like a boost leak symptom, I can almost guarantee that it's because of that coupler.

Thank you for the reply as well!

 

[Haase]

Running a basically stock t25 setup without turning up the boost I don't see any possible way that an intake and filter could make you hit fuel cut.... I would definitely do a boost leak test. You can take off your intake pipe from the cold side of the turbo and connect the BLT in place. That's where I always do mine from

 

[WES_393]

If the coupler connecting the intake pipe to the turbo is leaking, it will definitely cause issues like your describing. You may need to find a reducer coupler such as this: Forced Performance Turbochargers: FP 4" to 2.25" Reducer Coupler

It still wouldn't hurt to do a boost leak test though.

 

[SleepyGST]

Running a basically stock t25 setup without turning up the boost I don't see any possible way that an intake and filter could make you hit fuel cut....

Those were my thoughts exactly, but I wasn't too sure.

And yeah thats what I thought what the problem could be, just that the coupler isn't totally sealed, but I hit such a wall when I was testing it out on the road that I immediately thought it was fuel cut.

Thank you for the replies guys! I'll try that out and if I have any further problems I will just bump it I guess!

Update, I replaced the coupler connecting the intake to the turbo, which fit much better, and came out with the same results. Once I hit around 5k rpms I hit the same brick wall...this is my daily driver and even though I don't go over 5k often at all, it still sucks feeling afraid to go under boost

 

[We're on Boost]

When this happens, is it pretty violent? I've only hit fuel cut once ever, and it was a violent lurch (that was on my 1g).
The last time it happened - was there a loud pop? I'm thinking, if it is pretty violent like fuel cut, and the loud pop only happened the first time, it could be that an intercooler pipe popped out the first time, and ever since you've had a huge boost leak. A huge boost leak would let a lot of air out, increasing the air flow through the MAF, maybe enough to bring on fuel cut?
BTW, a boost leak wouldn't be because of anything on the intake side of the turbo. It would be something between the compressor outlet and the cylinder head.

 

[casperfast]

when you say hit a wall, do you mean that the acceleration looses, of that the car bucks and jerks? fuel cut is not comfortable on the car or the driver. if it is fuel cut then there is a possibility that your waste line came off and your overboosting. other than that,a boost leak wouldnt really cause this

 

[We're on Boost]

Has the fuel filter ever been replaced? If your air lines to the WG and fuel pressure regulator are ok and you don't have all the stuff you would need to do a boost leak test, you could start out by putting in a new fuel filter. Then if that doesn't work, get everything you would need for a BLT and do one.

 

[SleepyGST]

Hey thank you for the replies guys, but yeah the jerk is very violent and I just tried tonight after tightening a clamp around my BOV that was very very loose hoping that would do it, but it still did (including another loud 'pop').
And We're on Boost, to be honest I highly doubt the fact that the fuel filter has ever been changed. I am the second owner after 85k on it when bought and changed a few things for the cars first time. I can give that a shot! I also took a look at the WG lines and they are also still in place. I have yet to check the lines for the fuel pressure regulator, but I do have a boost gauge that is T'd into that line. The boost gauge is a very cheap one that basically came free with the piller pod, so is it possible that i have a leak there that could be serious enough?

 

[casperfast]

it is possible that if the line to the regulator was off then you would run lean, and cause a poor running condition. i would deffinatley check that.

 

[We're on Boost]

I have yet to check the lines for the fuel pressure regulator, but I do have a boost gauge that is T'd into that line. The boost gauge is a very cheap one that basically came free with the piller pod, so is it possible that i have a leak there that could be serious enough?

Well the idea of a leak in the small diameter line that goes to the fuel press regulator and your boost gauge is that it is important for your fuel pressure regulator to get accurate air pressure from the intake manifold plenum. If any of those lines, or the boost gage itself, have an air leak, it will lower the air pressure going to the fuel pressure regulator. That fools the regulator into thinking there is less boost than there really is, so it will make your fuel pressure lower than it should be, which would lean you out. I'm not so sure this would do what you are experiencing but it would be bad - it's something to be sure about - no leaks in that little air line.

 

[SleepyGST]

So I changed the fuel filter, holy balls was that over due! It looked like chunky oil pouring out of there! but I took it for a spin after a little bit of a drive and came out with the same results I'm planning on "bypassing" my boost gauge because i wouldn't doubt that there is a problem with the cheap material that was provided and hope that works. if not, i'm going to make my own BLTer.

I realize i haven't tried all possibilities yet, but is there anymore input that anyone can provide to add to the great previous posts?

 

[Nutty-GST]

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.

 

[DSMTyson]

Do a boost leak test up to at least 25psi

 

[Nutty-GST]

Going to try and get one this weekend. But if i have no leaks what could it be?

 

[spyderturbo007]

Fuel cut has nothing to do with fuel delivery. You can run 1000cc injectors on a 255HP pump and still hit fuel cut. The ECU doesn't know and frankly doesn't care about fuel delivery.

Fuel cut is caused by reaching a predetermined airflow setting dictated by the ECU's internal programming. I've been out of the game for a long time so I don't remember what that number is, but 2.55g/rev seems to ring a bell. Anyone know if that's right?

Anyway, do a boost leak test and fix the leaks. That should solve your problem.

 

[We're on Boost]

So I changed the fuel filter, holy balls was that over due! It looked like chunky oil pouring out of there! but I took it for a spin after a little bit of a drive and came out with the same results I'm planning on "bypassing" my boost gauge because i wouldn't doubt that there is a problem with the cheap material that was provided and hope that works. if not, i'm going to make my own BLTer.

I realize i haven't tried all possibilities yet, but is there anymore input that anyone can provide to add to the great previous posts?

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?

At some point, if you can't find anything wrong, you might have to cook up a way to log the signal that goes to your ecu from your Mass Air Flow sensor. As mentioned in post 18, the ecu throws a fuel cut when the MAS signal exceeds a certain value. You would have to find out what that threshold value is. If you can measure that you are getting near that level, then it could actually be a fuel cut. For instance, on the 1g, when this signal gets to about 2000 hz (so this is a frequency) the stock ecu throws a fuel cut.

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.

Is your downpipe and cat stock?

 

[Nutty-GST]

No its a ebay 2.5 or 3in but im not to sure was on there when i got it. and i have my dumptube rerouted into the exhaust as well

 

[We're on Boost]

No its a ebay 2.5 or 3in but im not to sure was on there when i got it. and i have my dumptube rerouted into the exhaust as well

Aha, then your problem could very well be hitting fuel cut. I think. I've never had a 2g and don't know much about them. But at 15 psi and a non-stock downpipe, a 1g would be all over fuel cut territory. The only reason people aren't suspecting fuel cut on Sleepy's car is because he apparently still is using the stock downpipe. SleepyGST are you still on stock downpipe?

 

[AngelOfPassion]

So I changed the fuel filter, holy balls was that over due! It looked like chunky oil pouring out of there! but I took it for a spin after a little bit of a drive and came out with the same results I'm planning on "bypassing" my boost gauge because i wouldn't doubt that there is a problem with the cheap material that was provided and hope that works. if not, i'm going to make my own BLTer.

I realize i haven't tried all possibilities yet, but is there anymore input that anyone can provide to add to the great previous posts?

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).

 

[Nutty-GST]

So how can i get rid of it? Do i have to buy dsmlink to get rid of it? Heheh i just want to be able to see what my car can really do!

 

[We're on Boost]

So how can i get rid of it? Do i have to buy dsmlink to get rid of it? Heheh i just want to be able to see what my car can really do!

dsmlink (ECMlink) would be the way of choice. But you would want to read up on it before you buy, so you know what you are getting in to. It's not everybody's cup of tea. But it would include a socketed ecu with one of their chips in it, capability for you to tune, and good logging capability - so you can tell what the heck is going on in there. When I shopped for engine management equipment a few years ago, I spent hours looking for an ecmlink manual to study. There wasn't one. I think there still isn't. But their web site is very good now. I think you can figure out the lay-of-the-land from the various pages on their web site, and there is plenty of ECMlink help available here in DSMtuners from users with experience.

A simpler way, if you have a so-called eprom ecu, is to get the eprom (chip) re-programmed by somebody who specializes in that. One of the guys in here who has a good rep for that is MY1GDSM. Here's a link to a recent thread where there was some discussion about this method:

http://www.dsmtuners.com/forums/newbie-forum/436670-custom-tuned-chip-question.html#post152984743

You can still use the custom chip method even if your ecu is not socketed. You would have to get your ecu socketed, or buy one that is socketed, then you can get a chip programed for it. The programing can remove the fuel cut thing entirely, and can compensate for bigger fuel injectors, higher fuel pressure, etc. But if you wanted to log while running, that would be a separate thing and I wouldn't know what to recommend for that! The logger I use is nice but no-longer made! Actually the most important things to log are A/F ratio (which would be a seperate add-on anyway with a wideband A/F sensor) and knock (which would be done by ECMlink from the stock knock sensor).

 

[WES_393]

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.

This is your problem, your simply running out of fuel. You can't run that much boost on that turbo with the stock fuel system. Turn the boost down.