Newbie ForumBeginner/newbie/general DSM modification questions. First mods, how to run 10's when you haven't run 12's yet, any tech question that doesn't fit in another tech forum. New Members must limit their tech posts to this forum and sub-forums.
When both the 14b's on my talon and the laser went out, they both would white smoke when boosting and also letting off of the gas after boosting. The laser would also smoke when it sat long periods of time while idling. After the bearings went out on the 14b from the laser, it ate the turbines and so I bought a b16g turbo. Every since then, I've had NO smoking problems from my car.
Oh, it was white smoke, and it was because of the seals in the turbo going out. Good luck
And I'm running 14psi on a Big16g all day long on the stock fuel system, including the fuel pump, with no problems. 15psi is a different story. And when people say check for boost leaks, do it. It can solve alot of your problems. Later
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Brian
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1) Car runs like poopie.
2) Car billows white smoke.
Have you ran a compression check yet? Does the car overheat at all? Have you looked to see if your oil looks like chocolate milk or to see if there's oil in your coolant?
Thank you guys, for all of the suggestions. I'm going to check the intercooler pipe along with the turbo tomorrow morning. I just took the car for a quick drive a few minutes ago and I hit about 7-8 PSI of boost without a problem, but I wasn't giving it much gas...I know as soon as it hits about 10 PSI or WOT it'll sputter and jerk like crazy.
Could the fuel pressure regulator really be the cause of the problems I'm experiencing though? With the jerking under high boost, the sputtering etc? Could the ECU be the problem? Being as the car has 450cc injectors in it (which was not stock for an automatic)?
Anyway, thanks for the help and I'll post my findings tomorrow.
No. Fuel cut is when your maf sees too much air coming in. This makes the ecu think that you're running dangerously high levels of boost or that it has a malfunctioning wastegate. The reason it thinks it see too much boost is because the turbo is working harder than it normally has to to maintain boost pressure that its losing from the leaks in your intake piping. While the outlet of the turbo is pushing 10 psi, the intake leaks are forcing the turbo to spool faster than normal and the maf is seeing the equivalent of ~20 psi or some other ridiculously high amount of boost. Go to the vfaq to see how to build a intake pressure tester and plug up your leak. Not all boost leaks will be clearly visible.
I have been trying to figure out my 2gb gst. I just got finished looking at the archives and found an article on fuel cut. I am curious my car has is all stock drivetrain except for a HKS filter cone on it. I have test everything or so I think with the exception of the Knock positioning sensor. My car is fouling out plugs but it is doing what the fuel cut article was talking about. It said that the car felt like the whole drivetrain was tearing out . Neways it sounds like it might be a ecu problem then and was wondering if my ecu out of my 2ga awd is the same so I could try swaping them. Also about the fouled plugs is that possible with fuel cut. Maybe the car is leaning out a higher rpms. The car doesn't idle surge but doesn't idle well at all.(around 300-500). Any help would be great. This problem started after the car had set for a while while I was living in Ohio playing hockey and it needed a new clutch. All started after changing the clutch and have been going crazy since. Thanks for any help
Got a 98 gst with evo III 16g, had a evo III ported o2 housing but last night i installed a dumptube. Drove it got on it a few times at the boost i had it set about before which was like 16, and it pulled hard i went to get tires and when leaving got next to an Evo and when i dropped to third and put my foot down it pulled hard but then made popping noises and stuttered. So i turned the controller down to 12 tried it again and it took a while then it creeped to 16 and got the popping and stuttering again. Now when i had the evo o2 on it i didnt notice any fuel cut when set at 16 i noticed when the gauge got to 16 it moved back and forth at 16 but couldnt feel any jerking or poping. All i could think of would be fuel cut but i would like to get that double checked with tuners. Also i though tthe dumptube decreased creep a great deal but i cant hold any pressure under 16.
ONe more thing sorry i also notice when under full accell, i can hear the dumptube and when i hit second and put my foot down i can hear the dumptube like the noise cuts in and out when under full boost.
i got on it today and i figured out what its doing,
the dumptube made my turbo creep really bad, my controller cant even touch it. i put my foot down in third looked at the gauge 19psi i saw that about shit myself and let off as im runnning stock injectors, so im suprised i thought dumptubes decreased boost creep i love the sound, but when i cant control the booost looks like its back to the evo o2 hosuing
i got on it today and i figured out what its doing,
the dumptube made my turbo creep really bad, my controller cant even touch it. i put my foot down in third looked at the gauge 19psi i saw that about shit myself and let off as im runnning stock injectors, so im suprised i thought dumptubes decreased boost creep i love the sound, but when i cant control the booost looks like its back to the evo o2 hosuing
i got on it today and i figured out what its doing,
the dumptube made my turbo creep really bad, my controller cant even touch it. i put my foot down in third looked at the gauge 19psi i saw that about shit myself and let off as im runnning stock injectors, so im suprised i thought dumptubes decreased boost creep i love the sound, but when i cant control the booost looks like its back to the evo o2 hosuing
Creeping is a good performance sign. You're creeping because your 2.5" tubular o2 flows better than the evo3 o2. Instead of going backwards and solve the creep by getting rid of the added performance you should move forward and port the turbine inlet and wastegate path to accommedate the added flow.
the turbo is fully ported.
the evo o2 was also ported to match the turbo both from same company.
i dont think the wastegate is opening fully.
That doesn't mean anything, my turbine and o2 housing was ported by Turbotrix and it creeped bad. There are two areas of special interest when porting to get rid of creep,
1. Take off material on top of the wastegate path so when you can actually see half of the wastegate when looking straight down. This way when the gate opens, air can flow directly out of the gate instead of making a almost 90 degree turn. The reason the dump tube didn't help you is because of this, without porting the entrance to the wastegate path you can still creep even with a external wastegate mounted on the o2.
2. Port behind the wastgate door to allow it to open so it's parallel to the flow, be careful with this step because you have a tubular o2 which is hard to port match what you did on the turbine side, port it just enough so the door opens more and clears the o2 side.
You can always go with external on the manifold but it costs more money and creats other undesireble side effects like noise and higher temperature in the engine bay...etc.
As it turns out, I got the car on a lift and found a lovely boost leak on the lower IC piping. The fuel cut issue was solved with a Keydiver Stage III Eprom in a 95 ECU. Interestingly enough, my creep issues are also gone and with the MBC set to 16PSI, I get a spike to 17 PSI which settles back to 16 almost instantaneously.
Fuel cut has nothing to do with your fuel system or what pump you are running. It is airflow related. You flow over a certain amount of air through the mas and you hit fuel cut.
I stand corrected (really). I got around my issues by installing a 95 EPROM ECU with fuel cut removed in the chip.
You can delay fuel cut by getting larger injectors (let's say 550cc's) and an SAFC-II. This will allow you to drop the airflow as seen by the ECU, which compensates for the larger injectors and keeps the ECU from cutting your fuel.
I agree with spyderturbo. You need to upgrade your injectors and get some tuning device. I made the stupid mistake of upgrading my turbo before updating fuel components. My car was slower than stock and made me sick to my stomach.
Now, after some 550's, MAFT, Walbro 255 that Big 16G is awesome.
Fuel cut has nothing to do with your fuel system or what pump you are running. It is airflow related. You flow over a certain amount of air through the mas and you hit fuel cut.
You nailed it. I can't even remember how many times I've answered that question.
For that, you get a rep point.
To clarify a tad, there are mitigating factors besides raw airflow numbers that the MAF sees that determine the exact point of fuel cut, including IAT, and some others I can't recall.
fuel cut has nothing on me. stock maf on 1g and i hit 21 22 psi on pump gas and no fuel cut.. all i did was remove all the honey comb things in the maf and cut the holes bigger and poof.. no more fuelcut.. down side for me.. crappy idle but i dont care becuse i was boosting 19 20 21 22 psi on stock 14b and no problems IM me if you need help :laser: :thumb:
fuel cut has nothing on me. stock maf on 1g and i hit 21 22 psi on pump gas and no fuel cut.. all i did was remove all the honey comb things in the maf and cut the holes bigger and poof.. no more fuelcut.. down side for me.. crappy idle but i dont care becuse i was boosting 19 20 21 22 psi on stock 14b and no problems IM me if you need help
you'll still hit it down the road again
but hacking the maf is a nice way to suppress it - i wouldnt go farther than removing the upper honeycomb though
also 2g suck with hacked mafs so that plan does not help 2gs
I have a B16G turbo w/ a Hallman Pro B.C. I turned the boost up, but immediatly hit fuel cut off. I kept hitting it all the way down to 11psi on my OBX Boost Gauge. Can't I run more boost? I don't have any ecu upgrade, but have a Greddy S-AFC and give it plenty of fuel. I also have an egt and it's always at or below 1. Don't stock GST's run 12-16psi? Why can't I run at least stock boost with a bigger turbo? What do I need to do?
Last edited by DSM GREENHORN; 03-29-2005 at 02:19 AM.
Reason: bad grammer
1, fuel cut is mis-diagnosed as much as crankwalk.
2, afc does not = plenty of fuel if ya have stock injectors and f/p
3, you get 1 on the EGT ? ( i dont know what that means)
your prob is prob spark related, wrong gap dirty plugs or bad wires.
does your car stumble/shudder/miss ? thats not fuel cut.
fuel cut feels like you just hit a brick wall.
2 ideas. boost leak (big one)
or possibly like in my case. The boost gauge has a break in the line and you are really running 23 psi. (on an almost stock 2g)
(HMMMM no wonder my car was so freaking fast till I hit fuel cut)
2 ideas. boost leak (big one)
or possibly like in my case. The boost gauge has a break in the line and you are really running 23 psi. (on an almost stock 2g)
(HMMMM no wonder my car was so freaking fast till I hit fuel cut)
I so totally did that too. I was like..shit this t25 isn't bad...lol. I know better now.
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Hammer_Gaidin
95 GST, 93 TSI AWD, 90 Talon N/T
i recently got my car back with a rebuilt 6 bolt motor swap. last night while driving it..it would start sputtering and missing around 3200 rpms...and it did this in every gear but first which actually would go alittle higher. so i would push in the clutch and rev the car while driving and the car would rev up fine so i threw out the whole rpm thing. so as it would get closer to 3k rpms i would take my foot outta the gas alittle bit and it would climb up past 3500 w/no problem. so i figure it has something to do with the boost. it does it around 4-5lbs of boost. i didnt wash inside the engine bay or anything just trying to figure this thing out. any help guys would be appreciated. most of the searching results just turn up ppl who hose down their motors.
My 6-bolt has been sputtering at light throttle around 2500-3000rpms with 0-vac/0-boost. Maybe its the same problem. Your not getting the random misfire CEL are you?
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Matt Lafond
BB 50-trim built 6-bolt 2.0L
E46 BMW
I cant figure out what is wrong wth my car.When i run the boost up to 12lbs in 1st thru 4th it just starts cutting out like i am hitting fuel cut?How could i be hitting fuel cut at 12lbs of boost.It will hold 12lbs if I do a pull from 5th gear but any other gear cuts out.Less than a month ago i could run 16lbs and be fine but ever since i resoldered my capacitors in my ecu it has did this. If i messed something up with that then my car probably wouldnt even run, right?I also just put in a new hallman boost controller. I have a 255 and i am venting(has ran fine befor with 16lbs)
Last edited by AHALLA05; 04-15-2005 at 06:49 PM.
Reason: found problem
![Fuel Cut: What is it? How do I fix it? [merged]](/forums/iconimages/newbie-forum/fuel-cut-what-how-do-i-fix-merged_ltr.gif)
. Neways it sounds like it might be a ecu problem then and was wondering if my ecu out of my 2ga awd is the same so I could try swaping them. Also about the fouled plugs is that possible with fuel cut. Maybe the car is leaning out a higher rpms. The car doesn't idle surge but doesn't idle well at all.(around 300-500). Any help would be great. This problem started after the car had set for a while while I was living in Ohio playing hockey and it needed a new clutch. All started after changing the clutch and have been going crazy since. Thanks for any help
I am Fuel cuts master
(HMMMM no wonder my car was so freaking fast till I hit fuel cut) 
