I shouldn't be butting in cuz I know nothing here....But...if you are getting that initial 2 seconds of power to the pump with the ign.....shouldn't it run?

When using (the 200 ohm's scale), to check continuity to ground, (on a ground wire), I'd hope you would see more like less than one, or a very low number.

Another reason to use that resistance scale to measure the "connectedness" (continuity/resistance in ohms), might be to see if one wire is connecting to another in the harness.

If there is power around, (key on and/or battery connected), the ground resistance numbers might be gibberish.

 

On the pdc where the fuel pump relay "plugs" in, I am getting 6.7v at c16 and c18 (16 is the constant from battery, 18 is the switched source). I tested both asd and fuel pump relays, both tested good, ohms were good.

I then went to c3 connector (gray) at the PCM and tested pin 12, (automatic shutdown relay output. This is from b17 at the PDC?) and I'm showing no voltage (should be getting a 12v signal?). I then tested that wire for continuity and I'm showing 3.8 ohms. That being said, I would assume there is a short in this circuit (a142) correct? Or am I thinking wrong?

 

Just to clarify.

Test asd relay and power terminals. All tested good. 12v showing at both the constant and switched terminals.

Tested fuel pump relay and power terminals. All tested good. 6.7v at both switched and constant terminals.

Test chassis side of fuel pump connector. Shows 12v initially then drops to 6v. Checked for ground continuity and it's good.

Checked for continuity on the fuel pump module and I believe it's good.

Went back to the ASD circuit.
Checked for voltage at the ASD output (C3 gray connector at the PCM) and show 0v. Check for continuity on the same circuit and get 3.8 ohms.

 

Here is a stupid question that I hadn't thought of and I should have. With a bad ASD circuit, shouldn't I be getting a CEL? The only time I get one is when I put the key to "key on engine off". I can use my scanner for codes and done get one, just says "0 codes". The only way I got the code 42 was to do the key trick. Then it flashed code 12, 42, and 55. On a 96 how do I tell if I have a "no buss" condition"? Could this be related to the jeep not starting? Maybe I'm looking in the wrong direction all together. I'm still at a loss on this jeep after a week and a half of testing everything I could think of.

 

Actually good point, I know on my buddies we bypassed the asd to get us home and it threw a cel for the asd

 

Just realized something else as well. Fuse number 7 on the PDC (large fuse should be a 30 amp fuse correct? ...the one that is in there is a 60 amp. Hmmm another issue from the previous owner.

 

ok.. I finally had a set of hands to help me out here. Turn the key on and the all the relays click, wait a second and the ASD relay trips. Any Ideas on where to start?

 

Did you check for spark? It might be your fuel pump is not running. I mean if it has power and ground I'd think it should run.

 

Just reading through this trying to wrap my head around it lol

With the key on you should see 12v in b18, b16, you should also see 12v in the a2 (c1 connector at pcm)

 

Your 6.7v puzzles me....with key on, should be 12v on c18, c16??

 

It depends on if I ground to the battery or use the relay ground. At the relay ground it's 6.7 volts at the battery I get 12. I'll retest it in a minute to double check. Had to come in to warm up.

Also, if I test continuity between the dark green/orange wire at the connector on the coil and the 30amp fuse terminals (fuse pulled out) in the PDC I get 140 ohms. This seems way high to me.

I tested the coil and both primary and secondary came back as good. 1.1ohm on primary, 11,700ohms on secondary.

 

Try removing the asd relay and jumping batt to the output. b16 to b17.
then take a seal beam light (this loads the circuit) connect one side green/orange wire, the other to ground, if the light is bright circuit is ok, dim or off open circuit or corrosion..test the asd at various components, inj, o2 sensors

 

I've gone over most of the circuits with a test light and a multimeter. Is using the sealed beam any different?

 

a multimeter will show you voltage, but it is possible to have voltage with minimal current flow. i have seen it before where a meter will show 12v, but will not light a seal beam. that circuit has a 30a fuse it should be able to carry a "load".
I am hoping tj or salad will read this and chime in....

 

TJ did a few posts back but he is a busy guy. I figure most are. I'm at my end with this. new CPS, new distributor pickup, new battery cables, new battery, added in grounds, tried a different PCM, new fuel pump, replaced ALL my relays, replaced ALL of my fuses, freshened up all the existing grounds, have been back and forth in the wiring harness trying to check this or that and I have gotten nowhere except I found more problems that I have gone and fixed so in the last week I've dumped $400 into this thing and still not running.

about a month ago I replaced the alt. and maybe this problem comes from that? I started cutting the loom for the alt/coil/oil pressure sending unit a little bit ago but called it a night, I'll finish that and look at the splices in the morning and put it all back together the move to what ever is next in that circuit.