Electrical NighTMaReS

[blackblazer717]

ok two days ago i had to have a tow truck come and haul me home =(, ive yet to figure out the problem and im very confused.
the truck stopped running, and now it will not fire at all, what could cause the truck to not fire the injectors and not produce any spark...? i replaced the cap, rotor, ignition coil, ignition module, fuel filter and i have no clue what it could be. please help. any clues would great any secret fusable links or something. thanks
luke

 

[readymix]

Is your fuel pump getting power??
My neighbor had a bod wire going to the pump relay and it caused the same issues you are having

 

[blackblazer717]

the fuel pump runs but the injectors dont fire

 

[hawkeye649]

[ QUOTE ]
the fuel pump runs but the injectors dont fire

[/ QUOTE ]

You need to get out a noid light and see if you get a grounding to one of the two wires that go to the two injectors. Each injector has two wires, one red and one black IIRC. I believe the "supply" wire is sys voltage (whatever your batt is at, 12~VDC) and the other should lead to "nothing". The ECM grounds this wire. You should see if youg get ground at the wire when it's, and then you should see if it grounds at the ECM.

More detail in how it died would help too. Have you tried to pull any codes? /forums/images/graemlins/thinking.gif

 

[dyeager535]

In other words, hook the two wires of the noid light to the two pins on the injector connector, and crank it...if the light flashes, you've got injector pulses. /forums/images/graemlins/smile.gif

 

[hawkeye649]

[ QUOTE ]
In other words, hook the two wires of the noid light to the two pins on the injector connector, and crank it...if the light flashes, you've got injector pulses. /forums/images/graemlins/smile.gif

[/ QUOTE ]

No it isn't that simple. One IIRC the pos wire will have constant voltage too it as long as the key is in the "on" position. So you want to attach a volt meter too that wire and see if you get any current flow from that wire to the neg post of the battery. If you don't see if it isn't a bad wire. If that works, then you should use a noid light from the pos post of the battery, or from the supply wire, too see if the ECM is grounding the wire for the injector. Then you should know if it's a fuel or an electrical problem. /forums/images/graemlins/waytogo.gif

 

[dyeager535]

Why isn't it that simple?

One wire is ECM ground, one is constant 12V per your message. If the truck is in run, but isn't being cranked, if the noid light stays on with both leads hooked up to the injector connector, you'd have a short to ground, no? Since the ECM controls GROUND, you don't have to worry about the noid light flashing if the engine isn't cranking, (and there is no short in the wiring) since there is no ground for the injector without a distributor reference pulse (cranking).

If the light pulses when the engine is cranked, since the ground is what is controlled through the ECM, then that means everything is ok.

I don't see the failure in logic of that.