Fuel pump hotwire

[Chris26]

FYI The pump was not under load when tested(connected to injectors and rail).....

[Paul Workman]

Originally Posted by Chris26

FYI The pump was not under load when tested(connected to injectors and rail).....

Just to be sure we're on the same page....

The connector at the fuel pump (for the record) is "C450"

With all circuitry connected normally, AND that includes the fuel lines to the injectors via the fuel rail(s), WITH the battery (pos) is passed through the VOM (configured to measure Amperes) to the FUEL PUMP PRIME CONNECTOR (the red wire/connector near the windshield wiper motor, jutting out of the big wire loom), you should read between 8 and 10 amperes (approx 1/2 of the current to each pump, is how that works).

However, if the current is NOT where it should be, by pulling the FP1 fuse you cut off the current to the FP1 circuit and what is left is the current flowing to FP2 only. Now, if FP2 is normal, under load (pumping fuel) it should read between 4 and 5 amperes.

CHECKING OUT THE HARNESS TO THE FUEL PUMPS:

With C450 disconnected (at the fuel pumps), separating the harness from the fuel pump apparatus, the ignition switch still in the OFF position, and the FUEL PUMP PRIME CONNECTOR no longer connected to anything, and all other connections, etc. in their normal condition/state (i.e., no jumpers or whatever else being present), the VOM configured to read resistance should read zero to 1 ohm or there 'bouts between the GRAY and the DARK GREEN/WHITE (harness) wires (feeding from the battery-side of the C450 connector, NOT the wires leading into the tank).

Again, reading resistance of the ground connection, the resistance measured between the BLACK wire (on the harness side) of the C450 connector and ground (e.g., the frame) should be very close to zero to 1 ohm (i.e., the amount of resistance one reads when the test leads are shorted when measuring ohms).

IF the above is true, i.e., the resistance reading recorded between the GRAY and the DARK GREEN/WHITE (harness) wires was at/near zero, AND the resistance between the BLACK ground wire of C450 of the harness is at/near zero, the harness "ohms out" FOR NOW.

Let's hear what you find/found.

[Chris26]

Thanks again!!! Any tips on how to remove bolts with cracked off heads from the coolant pipes to the injector housing??? I do not have a torch or anything like that. The car was a gift and TBH this is not going the way I planned it out...I'm supposed to be on vacation but instead have a s@#$load of parts on my kitchen table....If i had a garage ...proper resources...cool neighbours ...then I would not be complaining!!!!

[Chris26]

f@#K!!!! I should have never touched those bolts and just left the whole injector assembly together!!!!

[Chris26]

Ok!!! Broken studs removed..

[Paul Workman]

Originally Posted by Chris26

Ok!!! Broken studs removed..

Jerry has some stainless replacements, or you may have a machine Supply outlet nearby where you can also get them.

I put some RTV on the threads to keep water out and to keep them from seizing again. (Common problem after some years.)

[Chris26]

Would a clogged fuel filter cause this???....after old fuel and water ran through.

[Paul Workman]

Originally Posted by Chris26

Would a clogged fuel filter cause this???....after old fuel and water ran through.

Well, it would take solids of various sorts to plug the filter. If there was some debris in the bottom of the tank, certainly either the pick-up flilter(s)(attached to each pump) or the inline filter (on the frame rear of the RF wheel well) could become blocked.

As for the different current readings, assuming proper connections, the normal draw is 8-10A, divided between both primary and secondary pumps when both are under load (pumping fuel). (IDK what the current might be if they are not immersed in fuel.)

[Chris26]

ok I blew into the lines at the tank going to the fuel rails....and got a bunch of

crud and water out into my catch bottle ...the lines seem to be unblocked now.

But one problem....the fuel pump will not come on anymore after I try and jump

it. Is there a fusible link somewhere....near the battery area for the pumps???

FP1 fuse checks out fine...F&@k....I have a massive headache and working in

40+ degrees C is NOT FUN!!!!

[Chris26]

I'm getting current to the fuel tank connector.
(blew FP1 fuse in the process.)