94 GS Fuel Cut Off (New ECU needed?)

I have a big problem. Please help me out of you can. My fuel cuts at 3500 RPM. Here's what I got:

1994 Galant GS (4G64 DOHC. In short, a 4G64 block with a 63 head.)
T25 turbo mounted on a stock but ported 2G manifold (Yeah, I know it's small, but it was there.)
Methanol injection
Cheap boost gauge
3" piping from filter to turbo and from turbo to TB
3" DP and full 3" exhaust
450cc injectors
2G resister pack
ACT 2600 Lb clutch
9 Lb. flywheel
SAFC II
I'm sure there are some things I forgot. But, that's the most of it.

Before I had the SAFC II installed the car was running fine. I just couldn't get on it any cause it would lean out. I was told that the SAFC II would correct that and all would be good. I had the controller installed and tuned at a local shop. When I got the car back, it's fuel was cutting at 3500 RPM. The shop said they have it tuned to provide as much fuel as it can and it is just not enough. I'm hitting 5Lbs. of boost at idle, 12Lbs. at 2500 RPM, and it just keeps climbing. The wastegate is set to 9 Lbs. (It is in good order. The boost still gets way beyond what it's set at. 2 different shops can't figure out why.) I do not at all mind the boost being that high, but I have yet to replace any internals.
I have an ECU from a 97 Eclipse GST. (Not installed.) Would swapping that into my car correct anything? What can I do? I miss driving my car!

you are hitting 5 lbs of boost at idle.............................................. .................................................. .................................................. .............................................
uhuh.

I'm not even going to address that.


as far as your fuel cut,

more than likely its due to a boost leak and you are overrunning yoru injectors.


do a boost leak test and get back to us.

I know 5 Lbs. at idle sounds like complete BS. I get that. But it's doing it. I don't really care about the boost issue right now. I gotta fix this fuel cut problem. The boost test shows there's no leaking.
What do you mean by overrunning my injectors?

how are you supplying fuel? Did you rewire and or change your fuel pump? Just a thought, but I think DOHC hit it on the head.

You cant boost at idle unless you have a stutterbox. If you dont have a stutterbox, your boost gauge is faulty, at idle, your vacuum should be negative 15-20.

Are you running a wideband? What ECU are you using? With stock 450cc injectors and either a turbo 1g or 2g ECU, you should not even need an SAFC to run stock or under stock boost.

Id try setting the SAFC all back to 0, or write down what its set to now if you want to keep that info, then set it back. More then likely you have a big boost leak somewhere, I would highly recommend doing a boost leak test. A big boost leak can feel like fuel cut or misfires, I have had it happne to me several times.

I have only hit real fuel cut one time running 20psi on a stock tune and 510cc injectors and let me tell you its scary. Was doing a 3rd gear pull down the interstate and passing a car under a bridge when it happenned. The car was pulling descent then it felt like it just hit a brick wall and heard the loudest backfire I have ever heard from the engine bay. Scared me and the car next to me lol. After that I didnt really boost till I got my EPROM chip from Keydiver that eliminated fuel cut.

(Edit)
NM you are running the stock GS ECU. If I were you, I would try to get ahold of a 1g turbo ECU or a stock 95 Galant ECU as they have EPROM chips, then have Jeff-o at Keydiver make me a chip.

Like i said before......I also concur.

are you running the stock pump?

I put in a Walbro 255 lph fuel pump in it.

No stutterbox. No wideband. Stock '94 GS ECU. The leak test shows no boost leak. I didn't know 95's had eproms. I have a 95 that I'm not using right now due to a broke connecting rod. Should I swap in and chip or not chip the ECU from it, or use my '97 Eclipse GST ECU, or stay with the stock '94 GS ECU that is in the car right now?

Is there a way to check if the boost gauge is defective aside from just trying another one?

Aside from boost creep, before the SAFC was installed, it ran fine. I had to be easy on the throttle or it would lean out. The SAFC was suppose to correct that. But instead, it pulls great to 3500 then hits that "wall" and sputters like I'm running out of gas.

like youa re running out of gas.

not like the motor blew up?

Yes. Like I'm running out of gas.

more than likely you are blowing your spark out.

what plugs are you running?
what gap?

Hang on. I'll go check.

you need to be running NGK-R bpr6es
and i woudl reccomend a gap of .028.

any other plug will yeild crappy results.
don't use iridium, don't use platinum, don't use bosch, or champion, or zex or anything you can come up with.
only use the oem factory mitsu reccomended NGK.
denso plugs are also OEM replacement if you can't find a place in yoru area that sells NGK.
but make sure you don't get anything but the basic nickel plug.

make sure your wires are in tip top condition as well, i reccomend accel wires because they are relatively inexpensive, and an independant study on dsmtuners showed them more effective than wires 3 times as costly.


did you pull your plugs out? how do they look?

although its a bit unrelated. i'd reccomend repllacing yoru stock fuel filter with another oem fuel filter if you haven't done it in the last 30k miles.

there is no way you are getting any boost at idle. your bov woudl dump it all out. since it is seeing vacuum from the manifold. So you coudl probably count on your boost gauge being faulty, or its improperly installed.

are you recirculating your bov?

Sorry that took awhile. I couldn't find my plug gapper so I went and got another.

NKG-R BPR6ES plugs
NKG wires

Plugs gapped at .025, .023, .025, and .022 from passenger side to drivers. I don't think the slight differences between each other would cause that much of a problem. I'll regap them to .028. Plugs and wires are mostly new. They have been on the car for a year now, but it was only driven about 50 miles over a couple days then parked. Since then it has only been from garage to driveway and back a couple times.

The plugs are blackened to about a half inch up.

Fuel filter was replaced when I did the pump.

No BOV. Just a recirculation pipe, and an air bypass valve. I tried a BOV but it was LOUD! Very loud! I don't care to draw attention from any law enforcement agencies, so I took it off.

get some new plugs.

i change mine once a month.
.22 is rediculous.
your gap is way too tight.

I just gapped my plugs to .028, and reset all the fuel settings on the SAFC. My battery is dead, so I put a charger on it. I'll start it up in awhile and see what happens.

The plugs were new when I put them in. There's literally only 50 something miles on them. You think I'd need to change them anyway?

Ever do something stupid? Ever have a momentary lapse of cognitive faculties? I did. I reset the all the fuel settings back to 0% on my SAFC, then tried to start the car. Only I forgot to put the spark plugs back in. There was this horrid sound of my car gasping, then silence and everything was dead. Then I remembered my plugs. I gapped them to .028, put them back, then tried cranking it again. My "open door" light comes on when I open the door. The the glowy light around the ignition comes on but it's very dim. When I put the key in and turn it on my dash lights light up like they should. When I turn the key though, everything goes black and there is no attempt to start. No cranking, no clicking, nothing. If I turn the key off then back on the dash lights that come on are very dim, as if the battery is next to dead. I charged the battery for several hours. Same thing still happens. It's a newish battery. I have no doubt that it is good. All fuses are good. I do not have a meter to check the relays, but there aren't any (I don't think) that would have this effect if blown. Could it possibly be the starter or solenoid?

if the lights are dimming out, check your ground wires off the battery.
the wire from the battery to the body/block has a tendency to corrode which would cause that.
try running a jumper cable from the negative on your battery to your block and try starting it again

I have a blown ABS relay. I don't know how that would cause the car to act as if the battery is dead. But, it seems to be the issue. Of course auto parts stores do not carry it, so I'm gonna run up to my friendly neighborhood junk yard and find an ABS equipped Galant or Eclipse and get it's relay.

That wouldn't cause your car to not star.....It is something electrical like your battery or cables.....Check your posts and make sure theres no crude on them....Check your cables and make sure there snug and no corrosion on them....Also another thing you can do if you want to check your starter is get a set of jumper cables....Hook it up to your battery and disconnect all cables from the starter....hook up the postive to the postive hookup on the starter....Then with the negative touch the negative post....And if it spins your starter is allright....Another this is it could be the alternator...but the only fuse that would stop if from staring would be something for the fuel or ignition...and if its not even trying to turn over its somethin with your ignition....

Alright, I'm finally back to my car. Everything should be all good aside from my fuel issue. Is there anyone who is running an SAFC-2? What should I set all the values to? Not just the fuel, but all of them. DOHC Stunr, you're running the same engine. Different turbo, but same engine. Have you ran an SAFC? I can find info for Evos and 2G's but, of course, nothing specifically for Galants. I know each individual car will be different. I just would like to have a safe baseline to start from.
Any help is appreciated. Thanks.

Also, the is a 94 GS still OBD1? I have found people who say it is OBD2 even though OBD2 was not used till 96. I think. ??? I need to find what kind of logger I can use.

94-96 are OBD I - OBD II . Freaky weird hybrid thing :roll: . I made a topic about this earlier this week in 7G performance. Evoscan has been proven to work with the 7G as a logger. Downside being it runs off of a laptop.

Actually DOHCstunr was swapped out to a 4g63t with an eclipse ecu. I don't know if he ever ran an AFC and the only person I can recall who did was Peano and from what I remember he had problems with the afc. Your best bet might be switching over to an eclipse ecu but I don't know which one works for your setup(1g or 2g) or what exactly is required wiring wise. Good luck getting things figured out and make sure to let us know what happens.

Oh and if you decide you want to get rid of that 97gst ecu let me know how much you want for it. :wink:

the problem with safc's is that they lie to the ecu.

when you cut fuel on an safc... it adds timing.. which is exactly what you don't want to happen.

so all you can do to prevent this is to get a adjustable fuel pressure regulator. then run a lower pressure than stock, and add fuel that way(as opposed to taking fuel away)
this won't have adverse timing effects.


but if you are getting fuel cut... its because you are over running the injectors. having 450's and that tiny turbo... i woudl presume that its not an injector problem so much as a boost leak problem. you r turbo is pulling more air through than neccesery because its blowing boost out through leaks in your system. this cuases the injectors to increase duty cycle.... even though there is no additional air in the plenum.
so your ijectors maz out prematurely becuase of the spike in duty cycle..... and viola! your ecu cuts fuel.

you need to replace the gauge. Im pretty sure its faulty. you might be overboosting but you wouldnt know since you have a faulty gauge.

I'd say replace the gauge and see how much you are boosting. My buddy's SRT kept fuel cutting after 3000rpms cuz he was boosting more than 19lbs. on stock 550's. we changed plugs to OEM, and turned the boost down from spiking 19 and falling to 17 to spiking 17 and falling to 15psi, and voila the car pulls even harder.

just trying to help.

I'm not sure about you SAFC issue though.

OK. I have learned to install boost gauges. Removed and reinstalled it myself, and now it works. The "performance" shop that installed my gauge had the vacuum lines in the wrong places. I HATE Redline Performance with a passion!
I have figured out, I think, the fuel cutting issues. But I have a piston rattling all over the place when the RPM's get high. (A result of Redline Performance {They installed my boost gauge and SAFC.}attempting a dyno with my fuel being so lean.) So,,, I shall have to get new pistons. I'll go ahead and replace the rods too while it's apart and give it a metal head gasket. I'll keep the post updated as it progresses.