eaglescout526

That just doesn't sound like enough voltage for anything. But even applying 12V directly to the pump itself yielded near firing of the engine.

I still wonder if the fuel pump can put out but not enough pressure to keep up with the demand of the ECU and engine. Like yes we saw the pump can build the pressure but can it maintain that pressure when fuel is needed?

You snagged that one? Nice, looks good!

What Ωhm said.

On the pump itself should be two prongs. If the clips are attached wrong, the pump will blow bubbles and if they are clipped on the other way, it pump the fuel. But one of the wires going to the pump should be black indicating ground.

No little baby alligator clips laying around? Something like this makes me want to get a bunch of the weatherpak connectors and just make test connectors for power and ground like for the sending unit.

Oh ok. Makes me wonder if the fuel pump runs, but its not putting out enough pressure weather it is resistance in the wiring and connectors or the pump genuinely failing. But that's good that it primes, that takes care of that wonder.

Alright we are getting somewhere. Now we just need the fuel to get to the TB and keep the engine running. Pressure at the rail with this new development?

Relay or jumper in? Cranking or key on?

Just short of a miracle worker lol.

Good thing I got that Jeep/Eagle bolts bolts book. PN J0273573 is 5/16th in diameter, 18 in thread distance from tip to tip, 0.620 in shaft length and its made of steel.

Neither TBI or electrical book says. Let me go look at the 2.5L and FSM.

Maybe, just maybe. I'm crossing mine too.

So I wonder if that ground and the one that goes to the ICM come back to the dipstick ground. The one with the four splices is ground splice "D" that probably goes to the dipstick. On that second splice is a 20, 2 18's and 2 14 guage wires with a 14 going to the grounding point. Meanwhile the ICM ground and O2 sensor come together on probably the same eyelet at the dipstick.

Well with key on, I don't suspect there to be any voltage going through 87 until crank sequence. So O.L. would make sense to not be seen there as the relay isn't energized. I wonder what the second splice feeds then. Most if not all black wires in the harness are ground. But why would there be voltage there?

You can test for resistance and voltage and see if theres a drop.

Ah makes sense. Well he needs to make a build thread for us to watch.

Ok so that was splice "K" to EGR then FI then runs to the D1_6 in that mess and to another splice probably hidden in that mess. I am willing to bet the black splice is a ground, maybe like the CTS and ATS sensors ground, they do share a ground and splice in wire color brown with tracer. Then theres two other ground wires from the ECU that go into a splice that go to G110 and D2_7 on a black wire.

Crap there was also that one other member down at South Mountain, forget his username though. But may I ask what says it is him?

First splice should go from 87(one wire) to the splice which branches off four time, one to the EGR, one to the FI, one to D1_6 and one to C113. Then from C113 an orange wire goes to another splice of five more orange wires with a connector going nowhere and four going else where and to C100(bulkhead connector) But the second splice should be orange wires, not black so I am not sure about that second splice. I can't seem to find C114 in the schematics but it isn't under engine control. Do both connectors have an orange wire or just the one? If just the one that is the C113

So according to the schematic, from 87 on the relay, it goes to a splice, then from the splice it goes to the fuel injector, EGR solenoid and Connector 113 which is a four prong plug. There is also a C114 which looks identical to C113 but C113 should have an orange wire that leads to a splice that feeds a load swap relay, PS switch and to C100 which is the bulkhead under the clutch master cylinder, then from there it goes through the cab to the fuel pump connector.

Like I was saying early on, between the relay is two splices and two connecters. One of those could be corroded enough to cause issues.

Sure, lets see what happens. I wonder if theres something from the relay to the pump that would cause such a drop.

Is this with relay in socket?

Should be around 12V.