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dsm gurus please help. injectors not firing

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M1L3S

10+ Year Contributor
132
1
Apr 1, 2012
maple grove, Minnesota
Before I get flamed about the millions of threads covering this topic my has a unique spin to it.

I have read the other posts.

I checked cam and crank sensors.

Im getting spark.

getting fuel to the rail.

checked all relays.

Ecu is good

im just getting no injection.

If im getting fuel and spark. I should be getting injectors to fire because they run off the same current and switches ?

I have dsmlink v3.

I was having a freind do some basic tuning. Car was running. Then we turned it off and it never turned back on.

Is there something that in link could disrupt the injectors?

We set igntion timing took it around the block. Turned it off and it never turned back on.

How common is it for a black top to go bad ?

Any help would be greatly appreciated! Im stumped on this one.
 
Do you have power to the injetoctors? How about the resistor box? Also the ground side wiring can be checked. Give a quick visual for any unplugged or loose connectors and all ground wires. Maybe you bumped a signal wire on the cas connector when you were setting timing? Or did you mean on link you set timing?
 
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As mercaholik said, I would disconnect an injector and test the two leads on the connector. One side should be getting constant 12v and the other would be switched to ground when the injector is supposed to be firing. And yes, another place to check is the silver resistor box right in the middle of the firewall. I've never heard of one going bad, but they can come disconnected. If that yields nothing, you can always take a multimeter to the back of the ECU connector to see if the ECU is sending the signal at all.
 
I checked wiring. We set ignition timing by adjusting the black top cam angle sensor. Car idked we turned it off to save on gas and make a few adjustments.

Then it wouldn't start after
 
Did you un ground the connector or un check link? Can't you check a box when setting base ignition timing that serves the same purpose as grounding that connector by the firewall so ecu doesn't adjust timing. I don't know if that would cause s no start though.
 
Okay guys, so its still not starting! proving grounds is in 19 days :(

I replaced resistor pack, mfi relay.

car wont start.

I posted a log as to what its doing while I try to start it.

I don't understand why the throttlepos, and the the tps are both saying wide open?
 

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  • wont start log.elg
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I cant open lof from this pc but if its saying 100% tps then your injectors SHOULDNT fire. Thats an old trick ive heard about on dsms(and other FI cars): Hold the pedal to the floor to crank it without flooding it with fuel. Like if you were priming it cranking it over, you wouldnt want your injectors spraying fuel in there. Correct me if im wrong but i have read this on the forums several times over the years.
That would explain why your injectors arent firing if TPS is at wot, or so the ecu THINKS, right?
 
I cant open lof from this pc but if its saying 100% tps then your injectors SHOULDNT fire. Thats an old trick ive heard about on dsms(and other FI cars): Hold the pedal to the floor to crank it without flooding it with fuel. Like if you were priming it cranking it over, you wouldnt want your injectors spraying fuel in there. Correct me if im wrong but i have read this on the forums several times over the years.
That would explain why your injectors arent firing if TPS is at wot, or so the ecu THINKS, right?

At this point i'm willing to look at anything! I was wondering if it could be a bad tps? saying its at full wot? but why wouldn't the injectors fire?

car was running fine, not tuned. but fine. then we turned it off and it hasn't turned back on since .............
 
In the log it shows when I crank it that the tps goes to .63 and throttle is at 0% but then when I let it just log and not crank it stats that everything is full out wot! is there a bad sensor somewhere?

I have no idea what is going on with this thing.

I checked all my wiring. could it be a bad cas?

its getting fuel to the rail. spark. just no injection. even pulled rail out and placed it over paper towel. cranked and the towel was still completely dry ???
 
Yea, im pretty sure if the ecu thinks its at wot when cranking over to start it pulls all injector pulses. I gotta open the log.....

Ok opened the log, yea your TPS is screwy. Its wot. The ecu isnt going to open the injectors.
Have you tried calibrating it in link? Maybe a wire is loose or bad ground to the TPS.
 
Whats the word bro? You prob just got a bad wire thats all. Ring the wires out with a meter. Still curious: Have you done the TPS calibration in dsmlink?
Soon as you get to testing a new TPS or checking wiring update. Im really curious now if its what i think it is.
 
I'm not sure who said it already, or if it was in this thread but there are basically 2 sensors in the cas so you need a digital multi meter and perform some tests. Un bolt and take the cas out of end of cam, index out of course, and with power on but engine not running, spin the cas by hand. Check the signal wires for the appropriate voltage and/or resistance (ohms). First off do you have power at the injectors? Next ohm out the ground wire to the ecu, with no electricity running thru it. If that checked out they're is a whole list of things to check in a particular order, but you'll have to refer to the fsm for that. Also check all grounding and cables going to the ecu, I've had the battery terminal crack on me but it was still connected and would randomly not start. Like I said good visual inspection, and report back what you find out please.
 
Ok, i read your other thread. STILL bro, while you're cranking your throttle position is at ONE HUNDRED PERCENT, LOL. Not trying to be rude but it should not be at 100% while cranking. That millisecond dip to 0% TPS doesnt mean diddly squat. Its like your tps signal is 180 out??? Its completely back asswards. No matter: You have to ring the wiring and if you show me a log where its cranking AND tps is at 0 then ill show you a car thats shooting fuel out the injectors. Most likely a running car. I really think its a wiring issue and not the tps itself.

Let me dig through all my logs and try and find one where im starting it. Or anyone else care to post up a log while starting? I cant. I just tore my car down for a swap.
 
Ok, i read your other thread. STILL bro, while you're cranking your throttle position is at ONE HUNDRED PERCENT, LOL. Not trying to be rude but it should not be at 100% while cranking. That millisecond dip to 0% TPS doesnt mean diddly squat. Its like your tps signal is 180 out??? Its completely back asswards. No matter: You have to ring the wiring and if you show me a log where its cranking AND tps is at 0 then ill show you a car thats shooting fuel out the injectors. Most likely a running car. I really think its a wiring issue and not the tps itself.

Let me dig through all my logs and try and find one where im starting it. Or anyone else care to post up a log while starting? I cant. I just tore my car down for a swap.


If you read the whole threads you would know the car was running and cranking fine. This issue only happened after a freind adjusted both mechanical and electrical using link.

We adjusted cas so it was inspect

adjusted biss screw.

Adjusted screw to throttle plate.

Made adjustments in link.

After all adjustments the car still started and ran. Then we shut it off the last time and it would not start again. Hasent started since.
 
Not trying to sound like a asswhole. But its frustrating not knowing why something youve put so much time and effort in isnt running :banghead:
 
If the
I'm not sure who said it already, or if it was in this thread but there are basically 2 sensors in the cas so you need a digital multi meter and perform some tests. Un bolt and take the cas out of end of cam, index out of course, and with power on but engine not running, spin the cas by hand. Check the signal wires for the appropriate voltage and/or resistance (ohms). First off do you have power at the injectors? Next ohm out the ground wire to the ecu, with no electricity running thru it. If that checked out they're is a whole list of things to check in a particular order, but you'll have to refer to the fsm for that. Also check all grounding and cables going to the ecu, I've had the battery terminal crack on me but it was still connected and would randomly not start. Like I said good visual inspection, and report back what you find out please.


If the cas is bad. Why would throttle say 100% ?
 
Wow.... i guess its just one crazy, unexplainable problem. Maybe your car is setup to read 100% at idle and 0% at WOT??? Who knows. Sounds like a tough one though and i know the feeling. Boy, do i. 10 grand in on a piece of shit and going in another 10k after its all said n done. It stings to think about it.



I'll bow out of this one. Right now i have nothing more to contribute. Im going to tackly my own headache out in the shop
Good luck and i hope you find your problem and get back up and running.
 
Wow.... i guess its just one crazy, unexplainable problem. Maybe your car is setup to read 100% at idle and 0% at WOT??? Who knows. Sounds like a tough one though and i know the feeling. Boy, do i. 10 grand in on a piece of shit and going in another 10k after its all said n done. It stings to think about it.



I'll bow out of this one. Right now i have nothing more to contribute. Im going to tackly my own headache out in the shop
Good luck and i hope you find your problem and get back up and running.


Obviously its not meant to read that. But if you have nothing to contribute dont post.

Im not trying to attack you or anything like that. But being on edge and on a deadline, then hearing snark remarks isnt exactly helping the situation.

I wish you luck with your headache.
 
I posted a log as to what its doing while I try to start it.

I don't understand why the throttlepos, and the the tps are both saying wide open?

Looks like you are loosing the ground to the TPS while allows the TPS voltage to float to 5v.
You also are dipping below 8v during your cranking.

DSMLink will cut fuel off when it sees 100% TPS during cranking as has been noted elsewhere. The cranking voltage is very near shutting the ECU down. You shouldn't see below 10v if the battery and wiring is good
 
Looks like you are loosing the ground to the TPS while allows the TPS voltage to float to 5v.
You also are dipping below 8v during your cranking.

DSMLink will cut fuel off when it sees 100% TPS during cranking as has been noted elsewhere. The cranking voltage is very near shutting the ECU down. You shouldn't see below 10v if the battery and wiring is good


You were right. Unplugged tps. Car fired right up. Plug back in. And I have a no start. Im guessing its a bad tps.
 
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