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Resolved Fuel cut at 12psi

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JBDdsmer610

15+ Year Contributor
508
8
Mar 4, 2006
easton, Pennsylvania
ok everyone I've been trying to figure out why I have fuel cut at 12psi. I have a full 3in Megan turbo back, on a stock ported 14b, hard intake pipe with K&N filter, VRSF short route FMIC with a 1g crushed BOV, hacked 1g maf, fuel lab AFPR set at 46-47psi, EGR block off plate, and a hallman pro MBC. But as the title says I keep hitting a fuel cut at around 12psi and it wants to creep too. I have absolutely no boost leaks what so ever as I did a boost leak test twice last night. I just can't seem to figure out why I'm getting a fuel cut on some 12psi low boost...I need some help here guys any ideas or input would be great!!!
 
You didn't list what fuel pump and injectors are in the car, nor what you're using to tune everything with.

So, safe to assume you're stock in all those departments?
If so, the pump is probably maxed on flow and those 450cc injectors are probably at 100% of their duty cycle- ie. they're maxed out as well.

On my old Laser I hit fuel cut with literally no other mods apart from a straight pipe turbo-back.
 
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I find that hard to believe. I used to run 20psi on stock pump and injectors for at least 10 years. Never had any fuel cut. The reason you're hitting boost creep is most likely because your o2 housing. Is it stock still? Also why is the afpr turned up that high?
 
Sorry guys forgot to mention the injectors and pump but yes I'm on stock injectors and pump..I do have a set of 680cc injectors and full v3 ECM link with SD conversion but I haven't installed it yet cuz I need to get my wideband and bung welded into my DP. So I saw no point in installing that stuff without having a wide band hooked up..and another thing I have no idea where to start with the link I wish I could hook it up right now but is there really a point without my wide band hooked up yet? It's literally in the car wired up just need the bung put in and screw the sensor in and plug it in...and what PSI should I have the AFPR set at I thought it was supposed to be set at 46-47psi on the M/T cars??
 
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And I also have a full punishment SS O2 housing with a tial 38mm v-band wastegate vented but I thought it would be useless installing it on the 14b....opinions on that guys? Should I install it or should I leave the stock O2 housing?
 
Fuel cut is solely based on measured airflow. It's an ECU function and has nothing directly to do with injector or fuel pump size (It's suspected that it was based on a safe airflow for stock parts and intended to protect against a disconnected/broken wastegate hose). Real Fuel Cut is usually caused by a boost leak which raises the measured airflow but clearly turning the boost up can also trigger it.

Link just using the stock MAF is still very useful and should be the first thing you install right now. First it will eliminate the ECU fuel cut settings and allow you to log/debug as you add additional parts. Since your MAF is hacked it should output lower airflows and throw off the AFR, Link would allow you to correct that.

Without a log it's impossible to say if this is ECU induced Fuel Cut or something else.

So between the hacked MAF, higher base fuel pressure (1G MT's run 36.3 psi base), and no tuning tools right now it's had to give concrete causes. Go install your DSMLink now, do some basic tuning and post logs.
 
My daily driver has been running on 17psi(14b) for years and I never had problems with fuel cut. Logger says the airflow is maxed with a stock e931 eprom ecu. My other car has 272cams and a 14b/evo3 turbine and it hit fuel cut @12psi with a non eprom ecu. I never really figured out why the one never hit fuel cut, the injector duty cycle is over 100% and I know it has a boost leak at the compressor o-ring. The car that hit fuel cut had a boost leak at the throttle body shaft seal but held 7psi, anything more and it would bleed down.

Both airflow sensors had the lower honey comb removed and the screw removed.
 
I will start installing the link in about a half hour.i just replaced the fuel filter and turned the fuel pressure down to 37psi but the car had some trouble idling so I pruned it up to about 38.5psi and got it to idle fine. I also noticed my cam angle sensor was completely loose and flopping around so I tightened it up. I'm gonna take the car for a spin now and go do a little 3rd gear pull and see what happenes. As for the link I will hook it up like you are telling me too the only this missing from that equation is the wideband. I already have the AIT sensor welded into the throttle body elbo after the BOV and I also have a 3bar map sensor and the complete pigtail from ECM link. I just don't know where to start with the link it kinda scares me...I don't want to screw anything up on the car. I kno everyone here is very knowledgable and can help me with the link my main thing is getting it hooked up and getting the car to run right without doing damage, and should I hook up for speed density using the AIT and MAP sensor or go off the 1g MAF. I guess I'll have to start a thread in the tuning section when it comes to that.
 
And one other thing should I go ahead and install my 680cc injectors too while I install the ECM link...and instead of drilling and welding a bung in my DP I think I might buy one of those AEM no weld o2 bung sleeves and just drill the hole b/c I don't have a welder and don't really have access to one
 
IMHO, Don't do anything but install link. You can move to SD later. Get a baseline with what you have, learn how link works and then you can start adding other parts once you understand what the logs are telling you and what to change.
 
Ok Steve so install the link and run it off the stock 1g MAF, and don't install the injectors or the SD parts. Do I need to do any extra wiring besides plugging the link cable into the OBD 1 plug. Like any wiring to ECU pins or anything? I'll Deff get my ECU in tomorrow and get my laptop in the car and start playing around and get some logs at the same time and hopefully I can get them posted up tomorrow...I didn't get a chance to install my ECU and stuff today.
 
If you understand how to setup the injectors. Then throw in the 680's. If not then wait till you learn ecmlink more. Start by reading thru the wiki. Learn what you can log and why and how to use it, how to adjust. And anything else you need to know is on the link forums or here. Go thru the setup steps! Get your idle then cruise then wot dialed in :)
http://www.ecmtuning.com/wiki/
 
If you understand how to setup the injectors. Then throw in the 680's. If not then wait till you learn ecmlink more. Start by reading thru the wiki. Learn what you can log and why and how to use it, how to adjust. And anything else you need to know is on the link forums or here. Go thru the setup steps! Get your idle then cruise then wot dialed in :)
http://www.ecmtuning.com/wiki/

Ok I'll start playing around with it tomorrow. I'm just a little worried because I don't want to do any damage to anything and I think I may be better off running the link with the stock 450s for the time being until I understand the ECM link more.....and I need to get on the link forums as well, I need to email the admins so it will let me on cuz I'm not the original owner of the link so I need to have them reset or whatever they have to do
 
You def won't damage anything installing the 680's. Just make sure you use some fresh seals and the correct ones for those brand. As long as you do it right and sync them properly with your ecu. That's why i suggested waiting till you learn more. The wiki has the most information for setting up first time. Need anything just ask ;)
 
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Assuming that the EPROM ECU is the correct one for your car, you just unplug your old ECU, plug in the new one and reset everything back to defaults then set it for a hacked MAF. That's your starting point and from there follow the instructions on the DSMLink wiki.
 
ok so that vehicle profile is horrendously out of date or just plain incorrect.
install ecmlink using maf, even without a wideband, and update the profile.
report back after you have some logs to provide
 
And yes it is the correct ECU for my car it actually came out of my buddy's GVR4 when he had the link in it and I bought the link from him...and there is a setting in the link for a hacked maf? And yes I've been meaning to update my profile I was out of the DSM game for a couple years and that whole time I had an engine at the machine shop getting done witch is still there 3 years later and I get an excuse every time why it's not done. But enough of that I'll update my profile and start messing with the link in a little while...thanks guys I'm sure I will need some help with some things so u will be hearing from me
 
I tried to mess around with the link today but I couldn't get my laptop to pick up the USB cable for the link I tried installing drivers and everything so I think I need to get all the windows updates and I'm trying to get them now
 
This thread is marked as resolved, but i've read through it and didn't see what the fix was JBD!
Is your issue fixed and what fixed it ?
Same here. Fuel cut,bog, stalling,bucking......ect these types of threads are very common and the overwhelming majority of them have no resolve or explanation. Also seems once people experience this, they just drive grandma style since it appears as no one finds that golden egg of a fix.
 
:D That's totally not me, I'm hitting fuel cut in every gear and I just plan for it, make a nice poping noise shifting gears, but I want that 5k-7500 range back! I have a thread open on my issue, and I will post a conclusion when I fix it.
Think i've read through 1000's of posts with the last one saying well i'm going to try this or try that....
 
:D That's totally not me, I'm hitting fuel cut in every gear and I just plan for it, make a nice poping noise shifting gears, but I want that 5k-7500 range back! I have a thread open on my issue, and I will post a conclusion when I fix it.
Think i've read through 1000's of posts with the last one saying well i'm going to try this or try that....
You and me on the same SINKING ship.
 
You guys aren't the only one's. My car has 1200 miles on a fresh rebuild and is experiencing similar problems. Leave boost at 15 or lower and it runs without sputter, but turn up the boost and it spits and sputters, with the WB going lean for a millisecond then back to normal then lean again then back. At half throttle she will spin up to 8000 but just at a slower rate. I am chasing a ghost I guess and haven't found the problem yet. I checked 4 coils last night, 2 new and 2 off of running cars and all had 1.2 ohms on the Primary side (which is slightly out of spec) and all were in spec on the Secondary side. I thought I was having spark problems but swapping coils out did nothing for me, new wires, plugs...well its all new 1200 miles ago and ran very well when it was brand spanking new. I am following this to see if any info will help me and also if I find my problem I will suggest it on here too. Good luck!
 
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