ok, i think i just found something. when i tested the voltage at pins 37 and 57, i had the key off, and am getting 12.6 volts at the computer harness (computer disconnected), and the injectors (all of them). when i turned the key to the ON position, i'm now only getting 0.23 volts at the computer connector (computer still disconnected), and the injectors. does any of that make any sense?

i thought it should be the other way around, no? no voltage with key off, and voltage with key on? and the voltage at the battery with the key on stays at 12.6. and it still cranks fine (new battery, not weak or anything).

thanks in advance
-Mike

 

I can't tell you just yet where, but something is using your injector circuit for a ground.
Start with every ground you can see and every one in the diagram .
One of them has an open or poor connection.

 

found something new. i was checking everything again, and discovered that i'm getting 13 volts (had the charger on), at both he POSITIVE AND NEGATIVE wires of the injector harness with the key off, and with the key on, i'm getting 4 volts at both the POSITIVE and NEGATIVE.

wheni checked it the first time, i thought i had the computer in, but i didn't. so with the computer out, and key on, i was getting .23 volts. with the computer in, and key on, i'm getting 4 volts. any ideas? thanks

-Mike

 

I could be wrong, but this is what I would suggest you do.
If you have the computer unplugged and you are getting a reading at the injectors remove the EEC relay and the Fuel pump relay.
There could be a path thru either the EEC plug or the Fuel Pump Relay plug or the relays themselves. They are both fed from the same source and we have to eliminate that source.
Let me know if you get any change in readings when you do what I have suggested.

 

i'll be sure to check that tomorrow. another thing i didn't mention, is that i unplugged the ignition switch, just to see if it was "leaking" power to the fuel pump relay, but it was still getting power. also, i didn't seem to be getting a very good ground from pin numbers 20 40 and 60. 40 and 60 supposed to be the main computer grounds, and 20 supposed to be case ground. i cut them off of the main harness, and spliced wire onto the wires comming fromt he computer plug, and tied all three going to the negative of the battery. and i noticed when i disconnected the three new wires, i heard the EEC relay click off (computer still plugged in). i didn't check any voltages tho (it was late, lol). but i got to thinking about the case ground. by cutting that ground and running a new one, does that affect ahything? i see in the schematic, that that wires grounds out, but also forks off upwards to another wire. i can't tell if its to #16 ign ground, or to the wierd dotted-lined cylinder thing (what is that supposed to be anyway). or if what i did is fine.

also after some reasearching, i found a tool called a breakout box. they have one specifically for the 60 pin eec-iv connector. do you think this is something i should purchase? will this tool test the computer, and the harness? or just the harness? new they run about $600, but i see some good used ones on ebay for about $200. if you think this'll help, i'll order one asap, lol.

i'll let you know about the voltages without the relays. thanks.

-Mike

 

The dotted line cylindrical image means the wires are shielded.
A breakout box is nice to have . It doesn't do anything to check the computer , but makes it easier to do voltage checks instead of backprobing plugs etc.
I suspect a voltage feed going through wire #1 and don't know at this point if it is the relay, wiring or the plugs mentioned.

 

so do you think in my case i should get a breakout box, or is that only if the car runs (like to check for running issues)? I'm not sure excatly how it works, but in my mind, i picture hooking up this thing, and 59 lights lighting up (the one light not on, means thats where the issue is) lol. am i in the ball park, or way off?

 

With a breakout box if you wanted to check a particular circuit that goes to pin 60 at the computer for example, the breakout box will have a test hole that you can probe without going to the actual plug or wire. It goes between the plug on the computer and the computer to make access to a circuit easier to check with a piece of test equipment.
It does make it easier to check if circuits are functioning ,but does no actual testing on its own.
Numbered test holes on the box correspond with the pin #s of the computer.

 

FINALLY figured it out...... kinda, lol.

i went to pull a part (east side version of pick and pull), and got the entire harness from an f150 with a 5.0. the harness was close enough that i figured i could make it work. till i got home and realized on the engine there are those big fat connectors that basically connects the engine harness to the rest of the harness, and that mine had 5, and the f150 one had 4. there was an extra blue one. and when i disconnected them all except for the blue on, the injectors were still getting the wierd voltage readings. when disconnected, the injectors finally didn't get any power.

so thats when i decided that since the relays weren't doing what i wanted, that i'd make them do what i want, lol. I cut the EEC and Fuel pump relay connectors, and wires out. i kept the origional two fat yellow wires that run to the solenoid (that have the fusable links on the ends), and ran it straight to the battery. the red wires that supposed to feed power to all the sensors, injectors and to the computer. i cut the two wires off the computer connector, and T'd them in from the relays. IIRC, there were like 2 more wires that i snipped off the connector, and ran them straigt to the relays. i noticed on diagram it says the main wire that feds the fuel pump with power, T's off and also goes into the computer. that wire was blank on my computer connector, so i just left it off, and just ran the wire from the relay to the fuel pump. and the wire to the ignition switch, i just put an aligator clip on to activate the relay when i want.

so anyhoo, after all that i clipped the ignition wire, both relays clicked on, the fuel pump went out after 2 seconds, i got inside, and she fired right up. didn't even hesitate. it was like i've driven it everyday, lol. but it hasn't run in over 2 years since it origionally broke down (it was a repossession btw, RV place couldn't figure it out (master mechanics my hiney, lol)).

so nw i got to figure out why its leaning towrds one side. but i'll start another post for that one. thanks for all the help, i really appreciate it