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Ill check my stuff tomorrow at work. Read through somethings see if can come up with some to try and. To help you figure this weak injector pulse you have going on.
Definitely voltage supply issue. With not carrying current like it’s supposed to be.
I appreciate you participating on my thread. Really doesn’t make any sense!! :beatentodeath:
 
I checked again. I have 12v at the inj wires and 12v at the ECU connector and 12v to the MPI red supply wire.

I'm now wondering if I have 2 bad injector boards on the ecu's, or 2 bad CAS with both having bad fuel side senders

I traced the inj wires on another harness I have. Like opened up and followed them. The inj wires go from inj clip directly to the ECU connector and directly to MPI ground.

/Totally lost
 
Have you checked the cam angle sensor and crank angle sensor signals from your CAs?


I’d verify I’m getting at least spark. Which I think you said you did.

I have an oscilloscope so I can verify the cam signal and crank easily. But you can take a multimeter and put it on battery neg a positive lead on both signals from the cam and crankshaft I believe 88/89 on ecu pins or back probe at the connectors while spinning the rotor shaft on the CAs.

I still haven’t solved my issue but verified I’m getting injector pulse at the ecu. If you need help verifying I can try and make a video for you.

If you actually do the test for injector pulse at the ecu you can rule out the cas since it sends the ok to send injector signal to ecu.
 
Check this test out I just made this one my official go to for injector pulse.

1. Unplug the ecu.
2. Grab a safety pin of some sort to and alligator clip wire. You need to tap into the ground by the ecu so you can pull a ground to whatever relay circuit you have. My mpfi relay transfers power when grounded on pin 6.. from pin 4 to pins 2 and 3

This sends power to my injector harness FROM the resistors ETC!
IMG_0958.jpeg

For instance I have a 95. Its mpi/mfi relay is pertinent to the retardedness of this specific pin layout. Basically when you ground this relay at the correct pin, your injectors have a voltage to them. You know you jumped the pin correctly because voltage will show up again at your ecu harness.

I don’t know what year you have so trust me when I say you need to do some soul searching for that relay and get it bypassed by this ground jumper.

3. Measure voltage at the unplugged ecu harness where the injector pins are located

4.Now that you have current all the way to the ecu HARNESS- with the injector plugged in and KEY ON..

Take another ground jumper exactly like the last one and TOUCH the injector pin to ground.

5.The injector should click. The noid light should light up. Tap a couple times and make yourself feel the happiness of either being relieved or pissed.

5. No injector voltage means you have a cut in the wire which I doubt, all 4 wires???

6. This will rule out the wiring. Try it on another injector. You can take your camera phone and put it by an injector or harness plug noid to verify the light as you perform the test solo in the car.

I’m pretty confident the wiring is good. My ecu must be doing something weird in order to not fire my injectors.
 
Injectors are clogged. I just found a thread on ecmlinkn forum and the guy made a jumper harness from batt to inj and tapped ground wire on firewall and he got his unstuck. I did the same thing and mine barely pulsed. My FIC 750s are seized. Prolly the 10% ethanol and sitting for a year.

CLEAN OR GET NEW INJECTORS!

I'm gonna put in the FIC 950s I have here in asap and I bet it starts.
 
Dude that’s great!! What about your injector pulse? You didn’t noid light it? Probably better imo from what I’m gathering noid is a variable as there are other noid lights with and without incandescent bulbs.

Link that or copy and paste the text/screen shot the info in case someone reads this. I might even use it to be honest. The previous owner of my car never gave me the forum login info so I’m in the dark about the ecmlink forum.
 
Ok y’all I’m trying to keep this build thread in the loop. I opened another thread describing my issue. I have a good ecu. I have a good CAS from a 1g. But my injectors won’t fire, and I can’t see a noid light.

Bypassing the ecu, meaning- unplugged ecu.

I got the injector to open by jumping ground to the mpi relay and jumping ground also to pin 1. I’m testing pin 1 because all 4 injectors are responding the same. Injectors no worky.

Doing this test, I got my noid light to light up and my injector to open.

Blue just had his sudden break through. The stupid injectors. I have a cheap CRAPPY set of 1000cc injectors that are some universal china crap.

I think that might be the problem at least. I’m going to try and source some injectors since- I’m really not wanting to wait for my ecu to get sent out and then they say there’s nothing wrong.

I’m not sure when I’ll get them, I just need 1, and I might have one stored somewhere and I might not have one stored somewhere.

Life’s a little hectic right now and my son is about to turn 9 months. I got a lot on my plate but I’m trying to get this Dsm done. It needs to move from my mom’s driveway and she constantly has told me to move it. Whatever you do kids, don’t get a Dsm unless you’re ready to start being a diagnosis’ wizard.


So I did an injector pulse test through my oscilloscope. My scope has saved me countless hours and money because I’ve trouble shooted every single sensor I’ve tried to blame.

cam and crank signals,
Ecu
Now my injectors


Those 3/4 items are expensive af rn.

I’d be in at least 500$ for the replacement parts and that’s not considering I have dsmlink v3.

So here’s the last test I’ve done. I checked for injector pulse.

IMG_0968.jpeg

I believe this verified my ecu is good and sending a signal.

I have the ground hooked up to battery negative and the other lead of the scope is on injector signal side(green wire on a 2g injector #1 harness)

This test solidified that I am sincerely perplexed as to why my car is not firing?

Well blue pretty much had the SAME EXACT ISSUE but with different voltages that varied. I’m sad he’s not going to be visiting my page but I’m very happy he’s not mad at “dead car is dead” LOL.

So here we go, I’ll try and trouble shoot my injectors out of the car, and most likely source some real brand injectors. I’m super super low on money right now so I’m kind of SOL on ideas to get these but. The world will keep rotating, dsms will keep starting only monthly and people will be visiting this page until it gets resolved for their no start issue. My whole mission is to get people to stop throwing parts at their cars.

I’m there, I’ve been there.. not knowing a dang thing about cars. It’s been a 10 year journey and I’m only finally starting to take this into my own hands. If I can recommend any tool to own if you buy one of these cars I’d get an oscilloscope. You don’t need one, but you will NEED one in order to not go crazy. There’s cheap scopes as low as 100$ rn. You need to get good at diagnosis and understanding the pull down style 5v reference that these Chrysler based computers use.

It’ll transfer to a lot of other vehicles.

That’s about all I have for the moment. I’m at a stand still and am pretty much depending on God to get me to where I need to be.

Also, I’m feeling like the image on my bio. It’s a Dsm thing.

Anyway I’ll update you guys when I get some more eventful information or breadcrumb clues on what to attack next. I’m hoping it’s just the injectors.

Don’t ever buy Chinese Universal injectors!
 
Okay so I tried something new. I was going to try and buy some new injectors but I’m too poor for that atm.

I pulled the rail off since I have a mechanic buddy that says he doesn’t care my afpr says I have x amount of fuel pressure I have to have some type of security problem.

Well I noticed during a few tests on the CAS test where you pull it and key on, and the engine every once in a while would chooch over.. no idea why..

So I followed his instructions and pulled the rail off. Inspected the injectors. He wanted me to try turning the car over with the injectors out but everything inside me remembered what happened when I was testing my old injectors. It flew off the rail! My o rings are super chunky rn since they are new on the Chinese injectors (mostplus + is the brand don’t ever buy them) so I tried to hear out this idea. He said if when I crank, the injectors don’t spray to pull one off to check for fuel.

Well I’m running out of ideas and decided to try KEY On- rail off- CAS SPIN.

So I UNPLUGGED THE COIL PACK!!!
And listened for the fuel to shoot in (cas primes the fuel pump for me) the rail and what do you know. One of my injectors fired. What the heck!!!?

I couldn’t believe it. I heard a click and know since I don’t have my coil pack making those silly squish noises, I heard the injectors try to click. I only saw one, and as I kept spinning what do you know. An injector flew off LOL. So I stopped the video and the test and came in here to mention that about the injectors. Weirddddddd.

Since 1 fires, I’m going to try it again tomorrow and move that injector around. I have a 2 year warranty and maybe what do you know, maybeeeeee I can get these guys to give me a some more injectors.
 
Alright so I went back outside this morning and while the key was in On I rotated the CAS. For a moment it actually fired all 4. But as pressure built up, it stopped.
once enough pressure was built up all 4 stopped injecting.

WTF

Im wanting to test them with a 9v battery to check if they will fire.. It was weird that as SOON as the fuel hit the afpr, 1 by one I noticed they stopped and once pressure filled the rail they all stopped. I spun and spun the CAS and it would not shoot an injector. Once the pressure dropped I got 1 injector to fire before the pressure built up again and wouldnt not fire again.


:idontknow::idontknow::idontknow:

Okkkkkkkkkayyy,

I know at this point it IS my injectors.. But WHAT THE HECK... Maybe They are getting clogged? The rail is pulled so I'll check it out with a 9v and maybe try flushing the injectors with some degreaser and atf+4 fluid.

this is such a weird place to be at the moment. I'm glad I decided to manually check the fuel injectors. Also, the coil pack being unplugged makes this test a lot safer. I know some are not afraid of fuel burning your face off but.. I really don't want to be the guy in my bio LOL. Its a metaphor! I'm in the weeds and I just live with it unphased LOL. Not on fire!!
 
What base pressure are you driving those injectors? Normally people send their injectors out to be clean and balanced. I highly recommend making this a regular part of your build. Any injectors that are not new need to be serviced. It's the only way to ensure you don't lean out one piston over another, as WB will only tell you an average AFR result.
 
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Just came here to offer you encouragement to chase this down. Been following because at some point last fall, right before the car went into storage, the #3 injector stopped firing. These were new injectors from RA and the car used to run fine. When the #3 died, the engine ran very rough, so the #3 got replaced under warranty. Tried trading around the injectors and #3 wasn't getting a pulse.

Called Dave @ ECMTuning to ask if he would go through a black box ECU and repair it. He said he would, but in his experience, he could count on one hand the number of times an injector circuit has gone bad.

This means we have to delve into the wiring -- like you have -- to verify good continuity and connections and not looking forward to it. In fact, it just stopped raining daily two days ago, so we'll get going on the checking soon.

Thanks for sharing what you've been through and the information you've gathered along the way. Yes, this thread will be helpful now and in the future.
 
What base pressure are you driving those injectors? Normally people send their injectors out to be clean and balanced. I highly recommend making this a regular part of your build. Any injectors that are not new need to be serviced. It's the only way to ensure you don't lean out one piston over another, as WB will only tell you an average AFR result.
My afpr was at 48psi so I turned it down to 42.5.

I think the problem is these Chinese injectors apparently are "the suck". I have a friend who could let me try his injectors. 3 match and 1 is stock. Im not really helping myself out here but I also found my old set of Precision 1000cc injectors. They worked great while they were functioning.. Until this whole process started. I definitely need some new injectors. I was reading reviews and apparently they are terrible at low acceleration(the MOSTPLUS+ 1000cc injectors).. Which is all im asking for right now. But I'm glad I'm learning from this terrible mistake. I spent like 80 bucks on these and thats at a loss cause its been over a year, could have gotten my original cleaned probably.. I know the "new" injectors CAN fire. I just want to see if presented with an opportunity of a working injector.. any injector that is good, I can go in a row down the line, if none fire, or if I find one good injector..

I can rotate that injector from cylinder 1, 2,3 then four while moving the good injector(s) around.

Right now I'm just trying to verify my wiring and ecu are all good. I don't have the cheddar to buy some new injectors since I'm out the 80 bucks on top of this.

The one good thing is that the injectors came with really good injector o rings. Which i'll admit I cheaped out on that crap(maiNtEnAcE:banghead:) on my last set of precisions. They were from harbor freight which... the "Titon?" they WORKED.. But when it came to doing a crucial test that would have saved me SO MUCH TIME.. (testing the injectors with the rail out of the head while I spun the CAS) I could have been on this track from the get go.. I did this test a long time ago but with CRAPPY injector o rings from harbor freight which seal but cant hold the injector in the rail with the amount of pressure pushing against the injector. Gas would just go EVERYWHERE!!!! I know gofer had a dsmer he was helping and mentioned you SHOULD DO THIS TEST AND I AGREE! But make sure you let the car coooooooooool down, take the coil pack out of the test by disconnecting them..

These 80$ o rings :barf:on the other hand are capable of holding the injector in the rail allowing me to see sometimes (mostplus+)they fire and sometimes they dont. They like to fire mostly when no pressure is in the rail. WTF At least this will come up as a google search. "Harbor freight o rings" JUST LIKE MOSTPLUS INJECTORS try not to use these on your dsm! Just get OEM or something tested and true:beatentodeath:. All the reviews on the mostplus even on amazon are MOSTLY 75% of people having bad luck. I wouldn't trust these injectors as far as I could throw them. Nor any orings that cant hold an injector in the rail. while testing with the rail and injectors shooting at you. Please don't smoke a cigarette while doing this test, should be common sense but..The CAS is firing a spark during this test and should be out of the equation so you can ALSO hear the injectors clicking on and off. I noticed that when the mostplus do actually fire I can HEAR it clicking. When the pressure is at the rail and its presented with an opportunity to fire it for some reason stops clicking. I'm hoping someone else will mention another simple test. I just thought of this one last second. I started it with starting fluid, it ran great for a couple of seconds it was great to hear it running :(
 
Just came here to offer you encouragement to chase this down. Been following because at some point last fall, right before the car went into storage, the #3 injector stopped firing. These were new injectors from RA and the car used to run fine. When the #3 died, the engine ran very rough, so the #3 got replaced under warranty. Tried trading around the injectors and #3 wasn't getting a pulse.

Called Dave @ ECMTuning to ask if he would go through a black box ECU and repair it. He said he would, but in his experience, he could count on one hand the number of times an injector circuit has gone bad.

This means we have to delve into the wiring -- like you have -- to verify good continuity and connections and not looking forward to it. In fact, it just stopped raining daily two days ago, so we'll get going on the checking soon.

Thanks for sharing what you've been through and the information you've gathered along the way. Yes, this thread will be helpful now and in the future.
I read a post about always testing injectors like I had described in the post above. I think it can be very trouble shoot friendly if we can see a problem with an eye on it. I'm not in your specific situation so I can't relate on the step to go in, but since you're suspicious of your injector 3 circuit I would bypass the ecu with it unplugged and go through the steps of energizing(jumping to ground) your mpi relay and verify the circuit is capable of firing and injector.

Take a camera, set it up in the engine bay on circuit 3 and tap to ground that injector pin with another jumped ground and a paper clip how I described in that post. If you can hear that specific injector clicking you're pretty much verifying its CAPABLE of firing the injector. The variable is the continuity resistance that is present. But then also you have to care about your multimeter as sometimes there is a "static noise" that throws the reading off with cheap meters. I don't want you to be stupid anal about it but. Your contacts shouldnt be reading any resistance in a lead test while testing for ohms (continuity).

At least in a perfect situation. My meter is showing a pretty decent resistance in my leads. Some cheap ebay meter. It works great though and I'd mention having a scope is the ultimate fancy. Even a cheap 100$ one can save you a lot of time and trouble and actually empower you next time you try and solve a bad sensor problem. Seeing my VERIFIED injector pulse on a Oh-Silly-scope ultimately proved my ECU and CAS is functioning properly, getting to the injector harness. I could test it again(through the scope) at the ecu pins which..... Might be another test I could try. There's just some stupid variable here and I'm pretty sure I'm about to nip it in the butt with these injector issues. The noid light test is very disheartening but, with all diagnosis there is that false positive and negatives I'm glad I can say I'm prepared but I wish I had an led noid light so I could really be on my game for that test. I'll have to find some leds online theres a thread on a 3000gt forum about making a noid out of an led.

Diagnosis is 100% the reason people throw these cars in the trash. It seperates the fuel junky dsmer from the seasonal bought not built snowbird if you will.

I gotta admit I had no idea what I was doing when I first got this car. I could have quit, but I have a type of stubborness that can't let a titsubishi kick my ass
 
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I read a post about always testing injectors like I had described in the post above. I think it can be very trouble shoot friendly if we can see a problem with an eye on it. I'm not in your specific situation so I can't relate on the step to go in, but since you're suspicious of your injector 3 circuit I would bypass the ecu with it unplugged and go through the steps of energizing(jumping to ground) your mpi relay and verify the circuit is capable of firing and injector.

Take a camera, set it up in the engine bay on circuit 3 and tap to ground that injector pin with another jumped ground and a paper clip how I described in that post. If you can hear that specific injector clicking you're pretty much verifying its CAPABLE of firing the injector. The variable is the continuity resistance that is present. But then also you have to care about your multimeter as sometimes there is a "static noise" that throws the reading off with cheap meters. I don't want you to be stupid anal about it but. Your contacts shouldnt be reading any resistance in a lead test while testing for ohms (continuity).

Thank you. Then that is how we will test the wiring! We'll post the process and the results in our Build Thread.
 
Incredibly relieved atm.

I scoured my whole parts bin and found my old 1000cc precision injectors. I tested each one by taking a 9volt battery and attached alligator clips to the battery then to the injectors.

All but 1 would click. That was better than nothing so I began the process of reviving a dead injector. I had been here before I knew the process. You take atf fluid and pour it into the injector and set it upright so the fluid doesn’t fall out. I’d also try and click the injector with a 9volt battery to see if it was “back to life”.

Day by day I would do this and slowly it began clicking louder and louder. I tried to pass brake clean through it but it just would not fire through the injector. Desperate I watched a video on YT where a man hit his injectors with a screwdriver handle to revive a dead injector. I repeated his process of giving it a quick slap of a screwdriver handle and to my amazement the injector started passing brake clean through it while energized.

I came to a point where it was now shooting brake clean through the injector and I wanted to test it against the other injectors so I put them through the same process by hooking them up to a 9v battery while attempting to pass brake cleaner through them. 2 where stuck open and would shoot brake clean through without even being energized by the 9v. So I took my trusty new tool and whacked them with a screwdriver handle. They both came back to life and stopped being stuck open.

Once all 4 were passing fluid and energizing with a strong click I put them back on the fuel rail with new injector seals from my mostplus+ injectors. I did one final test with the CAS out of the camshaft and the key on.

To my amazement I could hear each injector clicking while spinning the CAS.

I’m pretty upset it took me nearly a year to figure this out, I wasn’t working on it all that year but I bought these injectors thinking this would solve my problem. It just fueled the problem more since these Chinese injectors are absolute trash and I would and will NEVER RECOMMEND THEM! They suck!! All 4 were behaving as if they were dead and began this build thread.

I became a good diagnoser but sheesh. I lost a lot of time and am out the 80$ I spent on them. Do yourself a favor and look up how to clean injectors if you’re really that desperate. Don’t buy some cheap replacement when you now know this information.

You can always buy a fuel injector test kit which run about 500$ but if you’re serious about doing it yourself I think it’s a worth while tool.

I’ll probably do this from now on, clean my injectors with carb cleaner instead since that is a better carbon cleaner but know brake clean does also work. Also you know the deal, be safe.. wear gloves, be cautious of sparks while energizing your injectors and watch where you attach the injector to the brake clean because the pressure can pop the injector off the tip. I won’t attach any pictures of how to run these tests since honestly they aren’t safe nor guaranteed. But YouTube has been a great help to get my injectors clean.
 
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