94 GS Fuel Cut Off (New ECU needed?)

[the_boogiman]

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!

[DOHCstunr]

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.

[the_boogiman]

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?

[bronxbombr]

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.

[seth98esT]

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.

[bronxbombr]

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

[DOHCstunr]

are you running the stock pump?

[the_boogiman]

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.

[DOHCstunr]

like youa re running out of gas.

not like the motor blew up?

[the_boogiman]

Yes. Like I'm running out of gas.

[DOHCstunr]

more than likely you are blowing your spark out.

what plugs are you running?
what gap?

[the_boogiman]

Hang on. I'll go check.

[DOHCstunr]

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?

[DOHCstunr]

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?

[the_boogiman]

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.

[DOHCstunr]

get some new plugs.

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

[the_boogiman]

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_boogiman]

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?

[the_boogiman]

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?

[frag_daddy_2007]

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