no power at injector?

[DSmdank]

so my car started running bad on the way home. found out 2 cyl were dead. its the 2 closest to the timing belt 1&2? not sure on the order. its getting spark. there is no fuel going to them i checked the volt while the key was in the ON postion but the car off im not sure if im doing that right because i dont get anything to any of the injector clips. i changed out the computer and does the same thing. ive searched but i cant really come up with anything good. im thinking its the resistor box. anyone have any ideas what i should check next? im stumped

 

[vernvision]

The injectors I believe are wired in pairs because it is a Karmen system. If 1 of the wires lets say shorts it will also short the other injector as it will not complete th circuit. I had the wires break around at the base of the harness. I just went to the wrecking yard and found some on a non turbo (runs cooler wires are in better shape usually) and rewired them which corrected the problem. I would suggest insulating the wires better than DSM did as that is why these crack and break. There is a lot of heat generated under the hood of these little beasts and with a 1990 you have probablly already have had to fix some wires as a result of this. If that doesn't work for you let us know and we can go from there.

 

[steve]

Each injector is wired to a resistor in the pack on the firewall. All the resistors are wired together to the MPI relay and through the MPI fuse to the battery. The ECU has individual control over each injector. If you know getting power to the injectors you need to check at the resistor pack.

 

[vernvision]

Ok I scanned out of my Mitsubishi service manual the images of the circuit diagram so that this can be better explained. I believe there is no difference between the 92 and 90's. If you need printable images of these email me and I will send you a better quality. Hope this helps!

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[DSmdank]

yea the car already had the injector clips changed. but i noticed after looking at it some more there cracked after the solder point on the old wire. probly gonna replace it would be a good idea. ill also pick up a resistor pack while im out.
thanks guy for the help.
one more question. when i turn the ket to the on position should i have power at them? or do i have to jump something?

 

[steve]

When i turn the ket to the on position should i have power at them? or do i have to jump something?

You should have power to them as soon as the ignition switch is in run or start and the MPI relay is activated. So if the ECU doesn't turn on the MPI relay nothing powered from the MPI circuit will be.

 

[DSmdank]

yea. i have power to the injectors. i supposed i was doing it wrong...

but i found out the problem. pulled the injectors and there full of rust
time for a new gas tank and -6 lines. anyone know where i would get a gas tank. im gonna try the junkyard tomorrow.

 

[vernvision]

Just don't buy yourself another piece of junk at the junkyard. It is likely that your tank is going to be in the same condition of theones at the yard especially because they could have been sitting for years with bad gas in them. You could take your and have it cleaned and resealed if it is not in too bad of shape. You should be sure to clean the fuel line out too. It might be full or crap as well. There are several people who can rebuild and flow test your injectors. You can search the forumns for links. If you can't find them I will see oif I can dig up the info for you if you need it. This why it is good to run your tank down and add a high quallity fuel system cleaner now and again like redline or better product.

FYI: I learned this from an old school racer and mechanic that a little bit of 2 cycle race oil in your tank now and again will prevent rust and rehydrate seals especially in carbs like accel pumps. He swears by it in fuel injectors to but I have only tried it once. It didn't affect the performance that I could see as far as screwing anything up in the fuel system since that was my biggest concern. If you do this it as at your own risk and I just thought I'd throw this out there for the experimenter.