The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support ExtremePSI
Please Support Fuel Injector Clinic

2G Fuel Cut or Boost Cut?... Need Help fast!

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Djames93

Probationary Member
7
0
Jul 5, 2012
LaPorte, Indiana
Hello, I recently got a 1996 Talon tsi. It has a 16g turbo and a GReddy FMIC and BoV.

The problem Im having is if I push the throttle too far the car will spool just fine but then during boost itll buck. If i let of the throttle just before the buck it wont happen?

Im thinking they put the 16g in without upgrading the injectors and fuel pump so its starving itself?

Ive also been told to check into my re-circulation because it could be that its not recirculated and needs to be, or I need a new MAF translator? Any help would be much appreciated, the faster the better!! Thanks
 
Last edited by a moderator:
Not upgrading injectors on a 16g, which are notorious for creeping.:hmm:

Does it feel like you hit a brick wall under full boost..Fuel cut..I would also do a blt, to be safe..But cut gets my vote;)
 
Sounds like a boost leak to me. All versions of the 16g (small, big, Evo3) can be ran at stock boost without upgrading the injectors, so long as your not creeping much past 10psi like Bud said. Not recirculating also won't affect performance at wide open throttle, it causes issues when letting off the gas.

How to check for boost leaks:
http://www.dsmtuners.com/forums/art...-boost-leak-test-how-boostpro-net-tester.html
 
Yes Bud the first time it happened it felt like i hit a wall, whole car bucked forward, scared the shit outta me LOL. where can I get one od those BLT gauges? and ive read it could be caused by bad plugs and wires, how would i check those?
Wes, how would i tell the difference between a boost leak or fuel cut? would that be why i need the gauge? Autozone rent able?
 
A boost leak is really common, and sometimes mistaken for parts need to be replaced or OMG WTF just hapened.

Plugs are easy to check, and cheap to replace..Make sure your gap is where it's supposed to be tho, under.032

Scared the shit out of me too when I didn't know what was going on.

A good thing about the stock ecu tho, is that fuel cut is a built in engine protection..Basically engine protection for dummies..I could see someone putting a gt35 on their dsm and trying to run x psi, on stock equipment.

If the auto parts stores here even knew what boost was,I would bake them cookies.
 
Wes, how would i tell the difference between a boost leak or fuel cut? would that be why i need the gauge? Autozone rent able?

A boost leak typically makes the car stutter, buck, jerk etc. You can keep accelerating, it's just not very pleasant or fast. Fuel cut feels like your suddenly dragging a concrete block. If there aren't teeth marks on the steering wheel, it isn't fuel cut.

Check this out for more info on fuel cut. But in my experience, 99.999% of the time someone is experiencing "fuel cut", it's just a boost leak.
http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/186971-what-fuel-cut.html

You also don't need the pressure gauge, you just need to pressurize the intake. Rig up some kind of coupler like the one shown that can be attached to the turbo inlet. Then pressurize the system to 5-10psi more than you plan to run and spray soapy water all over the intake pipes/intercooler/intake manifold and watch for bubbles. If you see bubbles, it's a boost leak.
 
Last edited by a moderator:
Wes, how would i go about pressurizing the FMIC system? Ill go try this now and report back my findings.
 
Hey Jordan, do you have a BLT gauge? If so, I live in Indiana maybe i can meet you and have you help me check it out?
 
Upon Flooring my car, I have stock boost controller, should be at 12psi but crept up to 15psi maybe above but the problem is.

When i floored it, boost gauge hit 15 psi, then my car staled for a split second but i noticed during the split second, the cars boost gauge hit 15psi... 0 boost, and back up to 15psi..


Is this fuel cut?
 
Boost leak for sure.:thumb:

When you leak boost, it runs richer causing you to hit fuel cut even at LOW boost (depending on the size of your leak)

Same problem in my winter dsm at stock boost (BCS still connected too) I'm just too damn lazy to go freeze my ass off in the garage to fix it.ROFL

In regards to a leak tester; you can find one on ebay for pretty cheap, or you can go to home depot and make one for cheaper.

Good luck!
 
I agree boost leak test but how much boost did it run? Could be there is a low fuel supply due to injectors or fuel pump. Regulator could be failing as well. Also the pcv could be failing and utimitly leaking boost into your valve cover. Last thing i can think of as of right now could be a fuel filter.
Start with the BLT and progress from there on to the next possible issue.
 
Yeah i have a tester and a air compressor. i just need a hose.

But, before it wouldnt do this.

I had some exhaust leaks keeping my 18g a little laggy so i threw on double gaskets and sealed them off.

Before i would hit 12psi creep to 15 down 12 and on.
Now it just straight to 15psi bogs and goes to 0psi and jumps up to building boost again.

My car requires 2 tries of cranking since its loosing fuel pressure when its turned off.
Maybe a fuel leak around also helping with the fuel cut.

Mods are:
Evo 8 fuel pump
Stock fuel pressure regulator
Evo BOV
intake
full 3" exhaust
18g turbo and stock boost controller
 
Last edited by a moderator:
I had this same problem in my 97 Gst. I bought the car dirt cheap because the owner couldn't figure it out. It was completely stock except for a 16g turbo upgrade and a very oversized atmospheric bov . It would run completely fine up untill i start hitting high boost, them it would feel like its hitting a fuel cut off and it would hesistate and when I let off the gas an run it again without boost it will run like nothing's wrong. All I did was swap the bov with a recirculated bov and upgraded to a fmic and never had the problem again. My guess is it was the bov but I'm not 100% ( when I say it was oversized, I mean it was huge, way to big for a factory set up.)hope this helps.
 
You probably fixed your boost leak with the new FMIC. Either that or the BOV was leaking.
 
Im having the same problem i havebig 16g. and255 with stock injectors and it is breaking up between 6 an 7 rpm. it is at 13 pounds and seems to run fine during day but at night its the. Cuts out hard you can hear the motor buck real hard... Im guessing its the same and to upgrade injectors ?
 
if you think you have fuel cut, maybe you should install a wideband and make sure you have enough fuel for sure that way you would know if your motor can handle the setup
 
That's one of my next on the list for my car i got alot of stuff to sell new and used and it won't let me post any classified so in the mean time Im just not getting on the car very hard. I was thinking about gettin the tatrix cable set up that is on the classified first page but it seem alittle cheap for the whole kit? How much do they usually run with an ecu ?
 
The Tactrix cable is for tuning the stock 98-99 flashable ECU.
 
if you think you have fuel cut, maybe you should install a wideband and make sure you have enough fuel for sure that way you would know if your motor can handle the setup

I think you may be mistaken. Fuel cut has nothing to do with the size of your injectors or pump or anything like that. It is a preset limit in the ecu of how much air is coming into the engine. When the airflow reaches this limit it cuts spark and fuel as a safety measure so you dont continue to hammer on it causing it to run lean and destroy the motor.
 
Yes Bud the first time it happened it felt like i hit a wall, whole car bucked forward, scared the shit outta me LOL. where can I get one od those BLT gauges? and ive read it could be caused by bad plugs and wires, how would i check those?
Wes, how would i tell the difference between a boost leak or fuel cut? would that be why i need the gauge? Autozone rent able?
This is probably solved but I will add my penny. Same issue, was increasing boost and at 15 was getting a buck followed by a loud misfire through the intake. I changed my spark plugs to next coldest heat range. For my car it had BPR6ES and I switched to BPR7ES. No more detonation.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top