Fuel Cut: What is it? How do I fix it? [merged] - Page 15

grizzly · 07-09-2004, 02:26 AM

yea you could by turning down the boost, but then I don't think you want to do that now do you. Or if you want you could get a fuel cut defencer, but a lot of people say that it's bad. you could also build your own just look it up on yahoo or something

OnlyNeed4 · 07-09-2004, 11:32 AM

i have the boost controller turned all the way down, to minimal boost. i make 9 psi and it hits fuel cut at 5k rpms and a bunch of black smoke shoots out the exhaust. no matter where i set the boost conroller, it still hits fuel cut at only 9 psi, i should be able to run atleast 12 psi shouldnt i?

94EclipseGST · 07-09-2004, 11:58 AM

Check to make sure your timing is not off. When my timing was off, I had very simular problems, with black smoke coming out and fuel cut. Once I adjusted the timing everything was fine.

97GS-TSpyder · 07-09-2004, 03:22 PM

check your BOV make sure its adjusted properly

FunkMasterChipZ · 07-10-2004, 02:38 PM

theres a product out there by HKS its called a fuel cut defender its a computer doohikkie that just fools it into not cuttin fuel www.hksusa.com

crankbender · 07-10-2004, 05:25 PM

Quote:

Originally Posted by FunkMasterChipZ

theres a product out there by HKS its called a fuel cut defender its a computer doohikkie that just fools it into not cuttin fuel www.hksusa.com

do not remove fuel cut with the stock fuel system...you will break things.

Black smoke = extra fuel. This tells me that you are leaking counted air through a boost leak. Boost leak check your car and fix the problems. This leak will also cause you to hit fuel cut at 9 psi and nothing else mentioned would do the same.

kpt4321 · 07-11-2004, 01:01 AM

You should not hit fuel cut until greater than 15 psi of boost, maybe 20. If you're cutting at 9 psi you have a big boost leak, guaranteed.

blcknspo0ln · 07-12-2004, 01:24 AM

affirmative. go to VFAQ.com if you're not familiar with making and testing for boost leaks. takes about 10 bucks and a half an hour of your time.

mine did the same thing, slow spool up and fuel cut at 12 psi.. then i discovered the 4" long slit in my hosing...

oh, and boosting past 13-14 psi on a stock fuel pump is the highest I would go. with a 190 I'd only go to 16 psi, which is what i'm at right now without any ill effects

thefisl · 07-13-2004, 10:58 AM

Ok, I got on the freeway and had to change lanes to get over onto the other freeway. It was very busy and I was getting close to the onramp, finally someone lets me by (one more lane to go). This lady was on her cell phone and either didnt notice me (which I doubt) or didnt care. Suffice to say she didnt let me through and I couldnt slow down enough so I missed the onramp.

That B1@tch!! So I speed up so that I can at least flip her off, then I hear my turbo spoolin more than ever b4 ( I thought this was due to the new BOV) then, all of a sudden I hit what I perceived as fuel cut. I was at about 4Krpm and then the car seemed to stop as if I hit the brakes for a second. I let off the gas and then everything was fine. I didnt bother to catch up to her. But I had to make like a 5 mile loop

to get going in the right direction.
So........I'm not sure if this is fuel cut or not, but the way I've heard it described, it seems like it. I know that I shouldn't be having this problem, b/c if you check my profile, I dont have sufficient mods to be at that point yet. All I have is a CAI, Greddy Type S (which I have connected both the nipples, the lower of which is T-ed into the line that goes from the turbo to the BCS). I know that I should have a boost gauge, but the other day I went to Autozone to get one and I asked the guy at the counter if they had any boost gauges and he said "What's a boobst gauge?" I was like

? This guy is retarded. Now I just got my ACT 2100 in right after I installed the BOV, so I never really got a chance to punch it. I think that I probably have a boost leak b/c I didn't have this problem with the stock BOV and I'm assuming that since the new one is holding more boost it caused a leak to open up or something. I want to get some opinions of what you guys think might be going on. I'm going to do a leak test but I don't have a boost gauge and in the vfaq it says to pressurize the system to something like 20 PSI and whatch the boost gauge to make sure you dont go over anything like that. What do you guys think? Please help.....

P.S.
sorry for the long post :o

james13 · 07-13-2004, 06:38 PM

i had the very same problem...and my boost controller was unhooked so my turbo was over boosting. Check to see if you have both top and bottem lines hooked up on the boost controller.

-james

boostedinaz · 07-15-2004, 11:16 AM

You need to get a boost gauge. There is no way around it. Go to www.jegs.com or www.summitracing.com and look for autometer gauges. They will have the gauge to your door in a few days. From there drive the car and see what the gauge goes to. Its been along time since I have ridden in a stock 2G so I dont remember what the stock boost is. i want to say 9 lbs. If it creeps or has problems then you need to find them and fix it.

Pressure test the intake to make sure that you dont have a leak. I would test to 20 psi becasue that will eliminate all leaks.

Michael

thefisl · 07-15-2004, 08:19 PM

ok... installed boost gauge (splitfire [side note it came with a t fitting that had a restrictor on it...dont know if thats ok but installed it n e way.])

Max vacuum ~25
vacuum @ idle ~20
Max boost ~20PSI!!! ( I really dont know since thats where the boost gauge maxes out!!)

Also, my car was trailing white .....it used to just puff it whenever i revved but today when i started to test the boost gauge it was smoking slightly at idle.....when i came back it stopped..... Please help....

boostedinaz · 07-15-2004, 09:00 PM

Quote:

Originally Posted by thefisl

Max boost ~20PSI!!! ( I really dont know since thats where the boost gauge maxes out!!)

There is you fuel cut right there. You are getting boost creep and need to figure out why and fix it.

Here is a qick search for yeah try these.
http://www.dsmtuners.com/forums/sear...earchid=153162

Michael

boostedinaz · 07-15-2004, 10:22 PM

Quote:

Originally Posted by thefisl

thanks.....that link you posted is a no go......

Weird.

Just type

boost creep

in the search and start reading.

Michael

thefisl · 07-16-2004, 11:51 AM

so mike you think its definitely boost creep? it couldnt be a boost leak? would a blown head gasket come in to play anywhere on this. ( i think my hg might be blown :thumbdown )

boostedinaz · 07-16-2004, 05:40 PM

Quote:

Originally Posted by thefisl

so mike you think its definitely boost creep? it couldnt be a boost leak? would a blown head gasket come in to play anywhere on this. ( i think my hg might be blown :thumbdown )

It could be a boost leak but from my experiance it will just go to the boost you set it at, but since it is leaking the turbo will be working alot harder. So now that is is working so hard is has to pull in more air it will hit fuel cut.

Do a leak test and see what comes up. After that get a boost controller and try to bring you boost doen to about 15 lbs and see if it stays. If it does great if not then go after the boost creep issue.

There are a few ways to test for a blown head gasket.
When the car is cool turn it on and pull the radiator cap. You will see bubbles in it if it is blown.
You can also do the same thing and leave the cap on and if the upper hose is hard before the thermostat opens, then it si blown.
The last is to do a leak down test. You will see a high percentage of leak down in the cylinder that the gasket doesnt seal.

There are more but those are the easy ones.

Michael

thefisl · 07-17-2004, 10:15 AM

Quote:

Originally Posted by boostedinaz

It could be a boost leak but from my experiance it will just go to the boost you set it at, but since it is leaking the turbo will be working alot harder. So now that is is working so hard is has to pull in more air it will hit fuel cut.

Do a leak test and see what comes up. After that get a boost controller and try to bring you boost doen to about 15 lbs and see if it stays. If it does great if not then go after the boost creep issue.

There are a few ways to test for a blown head gasket.
When the car is cool turn it on and pull the radiator cap. You will see bubbles in it if it is blown.
You can also do the same thing and leave the cap on and if the upper hose is hard before the thermostat opens, then it si blown.
The last is to do a leak down test. You will see a high percentage of leak down in the cylinder that the gasket doesnt seal.

There are more but those are the easy ones.

Michael

Ok, I checked the radiator cap......well I can't say I saw bubble persay.....it was like, well the only analogy that i can think of is this.....when you look at a river the water swirls around and creates very very very tiny bubbles........now I dont know if the cooland is supposed to just flow straight through or if it swirls around in there but thats exactly what it was doing...... can anybody go and look at theirs and describe what it looks like...... I can alwasy post a vid clip if thats possible....... Thanks guys.

jdurston · 07-26-2004, 10:30 AM

I am a DSM newbie, just picked up a 92 fwd turbo last week.

I think I am experiencing fuel cut. The boost does not seem to build very well at low rpms. At high rpms it really pulls but it always cuts out a bit past 6000 rpm. I don't have a decent boost gauge yet, but the stock gauge reads close to 1 kg/cm2 at high rpms, max throttle.
The wastegate actuator arm fell off the wastegate arm. I put it back on. (I think the original owner didn't tell me something.)
I can move the actuator rod but it takes considerable force. The wastegate arm moves fairly easily. Is there an easy way to check the actuator. Right now I am not driving the car. I don't want to blow my engine from overboosting.
I'll probably just try and get a used actuator from a junkyard if my original one is bad. What kind of pressure should I be seeing once I install my autometer boost gauge?

Thanks in advance.

Josh

SlowSpyder · 07-26-2004, 10:37 AM

if the pressure source is connected straight to the actuator then you should see about 7-9 psi

98GSX-WI · 08-01-2004, 08:23 AM

The majority of my mods are now installed (see profile)....the last mod I am having done for what I'm calling MY Stage 1 is the bigger fuel pump, regulator, gauge... When first increasing the boost, I eventually got to about 17-18 psi and then I got fuel cut (my intention wasn't to go that high, but seems good to find out when fuel cut would occur). Anyway, I backed it down to about 14-15 psi and it's running good. Question is, with a 255hp fuel pump, will this allow me to increase boost to 17-18psi--without fuel cut? The more I think about it, won't the bigger fuel pump just allow me to increase the boost without going to lean....if I get fuel cut before the bigger pump, won't I also get fuel cut at the higher boost after the bigger pump? I'm curious, because I read that fuel cut is only related to the air flow the MAS senses and that the ECU ultimately calculates based on the Hz, pressure, and temp. Thanks in advance. I'm finding upgrading this car very interesting, especially understanding exactly how everything works (in theory) and why certain things happen....