4Crawler

iTrader: (3)

As long as the ECU can (and does) ground the injectors, it sounds like they should be working, since that is all it takes to turn them on. Power comes in through the ballast resistor to all 4 injectors. ECU supplies the ground connection to complete the circuit. I suppose you could check for the on/off voltages at the resistor or the ECU connector, but you'll likely need an oscilloscope to see them (pulses many times/second - too fast for a digital or analog meter to see). Check the cab and engine ground connections to make sure they are clean and tight.

I still would look to the timing and also any air leaks between the AFM and the intake. Even the tiniest hole in the rubber boots and tubing can cause an engine not to run. Had that happen a few times on my '85. Engine would suddenly die and would also backfire when trying to restart.

Wildcat_4R

Here is a diagram of the injector wiring that I drew hopefully helping others out in the future. I cut all of the oxidized butt connectors out and redid all of the splices by soldering each of them. This lowered my resistance in the ECU ground wires significantly. Hopefully this will solve my problem. Once I get it all put back together, I'll be sure to double check all of my grounds and make sure there isn't a leak in the AFM tubing.

Wildcat_4R

UPDATE: Got the wiring harness put back together. Checked all of the wires....they are good to go. However, when I try to jump my fuel pump from the diagnostic ports, it no longer makes a sound. Could it be that a relay or fuse has been blown? I know the wires to my injectors are good. The ground cable that is on the intake plenum/intake is good. The grounds to the E01 and E02 connectors are good. The power coming from the solenoid resistor is good. What am I missing to get this thing working?

4Crawler

iTrader: (3)

You can see the typical wiring diagram on my web page (that was posted earlier):

http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

Wildcat_4R

Pulled CO relay and main relay and tested them. Both seem to be within the specs. My CO relay clicks when I turn the key to the "start" posistion, however it is not clicking in the "on" position when I have the jumper installed.
Checked fuel pump power and there is none. Is that related to the CO relay? It was working 2 days ago...which is pretty irritating.

Wildcat_4R

Is there a fuel pump fuse that I may be overlooking...doesn't say anything about it in my Haynes manual.

4Crawler

iTrader: (3)

The CO relay is pulled in by the STA input in the Start position. In the On position it is the AFM FP contact or the test jumper. Perhaps that winding is bad or there is a problem in the relay socket or the wiring to it.