3 Injectors wont fire

[billdo_83]

My car was stored over winter time and I tried to start it up just the other weekend. I put on parts over the winter time like a FMIC, Pro-M MAS and 800s.

Long story short 3 of my injectors arent firing and one of them is. I've put in stock injectors and the same 3 will not fire. I'm positive that I have fuel going to them. I was going to swap in a differnet resistor pack tommorw. What other things can I test out or swap out?

I tried a differnet ECU also and no luck on that.

 

[johnk]

Maybe the wiring harness for the injectors. Those plugs have seen a lot of heat over the last 13 years and maybe worn out. I had to rewire all the plugs around my thermostat because the wires got to brittle at the connetions and took a dive. They weren't all appearant at my first glance some where hanging on by a thread other's completely snapped with a little tug. If it turns out to be I think I saw new harnesses on MachV.com

 

[billdo_83]

I'll steal the harness from my other DSM and give that a try tommorw.
Good idea

 

[billdo_83]

I checked all of the wiring today and all the clips turned out to be good.

I changed out the CAS and that didnt make a difference. I swapped in a differnet ECU and resistor pack. I dont know what else to check here.

Power transistor?

I'm getting 9v from clip #3 and I'm not getting any voltage at any of the other injector clips.

I need some more ideas here.

 

[5spd4life]

deffinetly try your power tranistor, seeing it controls your coil pack, and everyone knows what that does hope i helped...look at my thread see if u can help me

 

[billdo_83]

Now I just need to get my hands on one and swap it in there. It sucks having to drive over an hour just to try one thing on the car and then drive back up to school.

 

[psychlow]

The power transistor just converts DC to AC to energize the coil pack (coils don't work on DC), so I don't see that being your issue. I'll take a look at the electrical schematics later on tonight and see if I can figure out some possible solutions for ya.

 

[billdo_83]

I can send you the wiring diagram for the Pro-M if you wish to see that also.

Also here is the wiring diagram for the car...
http://www.taboospeedshop.com/wiring.htm

 

[psychlow]

Sounds elementary, but based on the link you posted and this pinout, have you tried testing for continuity between pins 51, 52 and 61 and their respective injector plugs?

If you've tried a new ECU, the actual wiring is the only thing I can think of if you have one injector firing.

 

[billdo_83]

Out of the slew of things that we tested on sunday I really want to say that your suggestion was one of the things that we tested. When I go back to the car tommorw to throw on another power transistor I'll test them again just to make sure about that.

I've been stumping a lot of people with this problem

 

[billdo_83]

I tried out a differnet Power transistor and no luck with that either.

Should I rewire the ECU harness?

BTW: With the key on the on position injector clip #3 puts out 9.6~v and the rest of them put out 0

 

[johnk]

Just curious if you have checked for any CEL codes yet?

 

[johnk]

Found this thread shows you how to manually fire an injector to see if it is still good

http://www.dsmtuner.com/forums/showpost.php?p=1445299&postcount=27

 

[billdo_83]

I had a code come up before that was
25: Barometric Pressure Sensor.

 

[billdo_83]

Found this thread shows you how to manually fire an injector to see if it is still good

http://www.dsmtuner.com/forums/showpost.php?p=1445299&postcount=27

I've swapped oodles of injectors around and I keep on getting the one firing in Cylinder 3 so I dont think its an injector problem. I've also tried out multiple sets.

 

[johnk]

OK so you've swapped out working parts for ECU, Resistors and injectors. How do you know that one injector is firing? It's not enough to run the car on. Are you checking it for sound or current?

What's a pro M MAS have your tried using your stock MAS?

It should be good if any injectors are working but have you checked your MPI fuse?

 

[psychlow]

I'm thinking something got hosed on the harness - it may be shorted to ground.

AFAIK, you should not be seeing any voltage on that injector clip unless the engine is running and the CAS is getting pulsed.

 

[billdo_83]

I know one injector is firing becuase that cylinder is soaked with gas and the other cylinders are as dry as a bone.

A Pro-M is a Mustang MAS and its a new product for the DSM market and Import community that is hitting the shelves shortly. Its been run on a few cars now and no problems with them.

I will try a stock MAS next time I go back to the car and see what happens.

I'll also try taking out the CAS and spinning it around to see if I can hear the injectors firing at all...

I looked through the harness tonite and couldnt really find anything. I'm thinking that I may need to buy a new harness or else run all new wiring. That would def not be cool.

 

[BISHILVR]

The mas has nothing to do with getting voltage to your injector connectors, you can start the car with no mas plugged in at all. I would say that since storing your car a critter or two have taken up housekeeping and made a meal outta your wiring harness somewhere???. That's the only logical reason i can think of if it ran ok when you parked it. also psychlow coils work on DC every day like it's they're job!!!, if you dont think so then explain a points and condensor system???, there's no dc/ac conversion taking place there. The ignition transistor does not convert DC to AC, it amplifies the signal pulses from the cas and does some buffering, etc. then it sends its output to the ecu/coil pack (depends on the application). I can see where it seems like it produces AC but it really does'nt produce anything on it's own, just outputs pulsed DC in a different form than it originally recieved it. Not cuttin on you, just a little f.y.i.

 

[zephyr_8]

you haven't done any welding on your car lately by any chance?

 

[billdo_83]

No welding on the car over the winter time at all.

I'm going to start going through wiring and see if there is bad wires someplace that are maybe no connected or touching.

I'm also going to redo the ground for the ECU becuase I have already have had one bad ground over wintertime (My starter ground had to be redone) so maybe that is the cause also.