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Unread 10-28-2013, 01:37 PM   #16
Que89YJ
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He meant weld spot. Spell check can be a double edged sword.

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Unread 10-28-2013, 02:13 PM   #17
flipit
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Quote:
Originally Posted by Que89YJ View Post
No, you are explaining it. There should be no voltage with the key off. It is wired wrong. The fact that you have 12 there doesn't tell you everything you need to know except that if that was left on the way it was wired you will kill the battery and or the pump. You need to pull the pdc and check the fuel pump wiring at the relay.

Check your fuel pump by jumping power direct to the pump. You have the pump out so take up front and put power right from the battery to it.
haha, you're killing me Que!
I dont feel like requoting myself, so i'll just say, toaday at 1:14 am-
so i pulled off the fuel pump,
took the two cables, put one on the batterys ground terminal,
and one on the positive terminal.
then at 3:11 pm
I used the two pieces of wire on the unit to test the fuel pump, and I got nothing. and both wires were in good working order, no resistance worth noting.
the bottom line is~

All three wires going into the pump are as mentioned, in working order (except the hot is strangely always hot)
the fuel pump has been "jump tested" and it did not work.
it's broken, malfunctioning, pick a word.
I am not sure what i did to it,
but i would PREFER to not fry it again.
being a college student, I can only afford so many $70 fuel pumps.
so would that constant voltage really be a problem that would break a fuel pump?
I guess i should backtrack.
I bought the jeep in 08, with the wiring in it's current predicament.
I drove it for a year, and then one day, after playing in some mud,
I got towed home. I cleaned up the Jeep, and attempted to fire her up, and it made the clear indication that it was not receiving gas.
I opened the tank and saw a glittered tank- the pump had some how grinded itself and decided not to work anymore.
so I replaced it, and the second one either never worked,
or pretty much instantly broke, I'm not sure i did not get enough time to fully test, now I'm testing all the parts, trying to find out what i can do to make sure the next pump lasts a lot longer than this one has.
Is it actually bad for those 12v to be constant?
or will that just drain my battery?

oh, and thanks for clearing that typo again.
I thought the wide spot was some sort of term,
like the skinny pedal you know?
skinny pedal i get, that one is easy,
but wide spot lost me.
the weld spot is good though,
like I said, the whole ground, grounds.
all along the wire and at the sending unit. it's grounded.
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Unread 10-28-2013, 03:25 PM   #18
laybackman
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4.0? no 5.0 Doh!
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Unread 10-28-2013, 04:26 PM   #19
Que89YJ
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He has a ford 5.0 in it! Pdc is bypassed and power is coming out of the ECU directly to the pump.
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Unread 10-28-2013, 04:26 PM   #20
flipit
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so, it has been brought to my attention that I missed out some important information-
the engine that needs fuel is a 5.0 HO- from a 95 mustang.
the hot wire is spliced into the main computer, and it is always hot- which it seems is frying my pump,
so the problem is weird because this happened after almost a year of driving, not at first.
and the plan is to try to get that hot wire back on it's original track so that it's only hot when the key is allowing it to be.

I'm off to grab some parts for my Dana 44 and then I have class, should be back in about six hours.
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Unread 10-28-2013, 04:28 PM   #21
Que89YJ
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He needs to write the fuel pump back to the pdc and wire a switched ignition to control it. It sounds like he has the stock pdc still.
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Unread 10-28-2013, 06:27 PM   #22
laybackman
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Quote:
Originally Posted by Que89YJ View Post
He has a ford 5.0 in it! Pdc is bypassed and power is coming out of the ECU directly to the pump.
Damn! The OP is a real smarty pants. He had the unmitigated gall to post all the pertinent information about his YJ in his profile....How dare he do that!

JK!

I assumed it was a 2.5 or a 4.0 and NEVER thought to check his profile. Doh!!
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Unread 10-28-2013, 06:30 PM   #23
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Quote:
Originally Posted by Que89YJ View Post
He needs to write the fuel pump back to the pdc and wire a switched ignition to control it. It sounds like he has the stock pdc still.
Why can't he use the stock wiring at the gas tank for the 5.0 fuel pump?
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Unread 10-28-2013, 07:15 PM   #24
Que89YJ
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The po cut it so part of it is there and part isn't. I think he should use as much as he can. He is going to need help figuring out where the po cut it between the ignition switch and the pdc.

We are definitely on the same page. The only problem I can see is the fuel pump will be on when the ignition switch its turned on because the ECU will not be controlling it....unless we have him wire a kill switch for it.
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Unread 10-28-2013, 10:07 PM   #25
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Quote:
Originally Posted by laybackman View Post
Damn! The OP is a real smarty pants. He had the unmitigated gall to post all the pertinent information about his YJ in his profile....How dare he do that!

JK!

I assumed it was a 2.5 or a 4.0 and NEVER thought to check his profile. Doh!!
haha, I have been surfing on JF for a while, trying to learn the tricks of the trade,
and MANY times have i seen a guy create an account with his first post being a question, and the first answer being "we could help you more if your profile is finished"
so yep. got my profile all set up.
honestly, If i thought it was important, I would have started with that.
so that you didn't have to go and look.
but for some reason i assumed my wiring was normal.
I'll consult my associate and we will check all three wires going into the fuel pump, then check it with the wiring diagram from
http://www.jeep4x4center.com/knowled...?utm_source=cj
as was mentioned earlier,
and if any are alternatively routed, as the one is- i will look into chaging them.
I can tell you already that the gauge wire (dk blue) actually goes from dk blue to red, and then fades into a pink and is spliced back into the blue again on top. the PO (previous owner, or problem originator, take your pick) obviousely had unique wiring skills which I knew would have to be addressed eventually, I just cannot wrap my head around the fact that
-It worked fine, until I went mudding one time, and came back, then after clean up I tried to start it and nothing. metal shavings in the gas from the first fuel pump, replaced it brand new, let it sit for four years, and the new one doesn't turn on either.-
so now the idea is that the steady 12v current fried the pump, well how come the first one lasted for so long?
maybe during my mudding I broke something right at the end?
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Unread 10-28-2013, 10:10 PM   #26
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Originally Posted by Que89YJ View Post
....unless we have him wire a kill switch for it.
I would really prefer, really, really prefer to NOT add extra wires into the mix right now. If i can run out back tomorrow for a bit, I'll take some shots of the wiring set up I have, just to show how hectic it really gets...
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Unread 10-29-2013, 03:56 AM   #27
Que89YJ
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No extra wires. Right now your pump is not all the time, with a rewire the pump will come off the fuel pump relay. Like I said though, you will have constant power while the ignition its on. The pump is wired to go off if you get into a wreck the engine cutting off will also kill the pump. It's easier to just wire it with the switch ignition. I bet if you can find the wiring diagram for the 5.0 ecu you will find a switched ground pin to control the fuel pump relay. We can wire the switch ignition feed for it but you are going to need to figure out the year for the ECU A's a wiring diagram if you want to wire it in for the ECU to switch the ground.
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Unread 10-29-2013, 05:41 AM   #28
laybackman
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Quote:
Originally Posted by Que89YJ View Post
No extra wires. Right now your pump is not all the time, with a rewire the pump will come off the fuel pump relay. Like I said though, you will have constant power while the ignition its on. The pump is wired to go off if you get into a wreck the engine cutting off will also kill the pump. It's easier to just wire it with the switch ignition. I bet if you can find the wiring diagram for the 5.0 ecu you will find a switched ground pin to control the fuel pump relay. We can wire the switch ignition feed for it but you are going to need to figure out the year for the ECU A's a wiring diagram if you want to wire it in for the ECU to switch the ground.
I found this. Pin #19?

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Unread 10-29-2013, 05:51 AM   #29
Que89YJ
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Flipit check on the ecu and see if this wiring diagram matches your ecu and if you have a wire for that pin. If you do then we are going to be able to get you setup real easy.
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Unread 10-29-2013, 08:33 AM   #30
flipit
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Originally Posted by Que89YJ View Post
The pump is wired to go off if you get into a wreck the engine cutting off will also kill the pump
Okay...let's just run with this exact part for a short moment.
Let's say that the PO wired this whole thing, and it worked great,
then maybe for some reason my engine cuts off, maybe the air filter gets clogged, or maybe I pinched the air filter tube and it's not getting enough air or something (just go with it) and so the ECU is getting an incorrect reading for the air to fuel ratio, and it decides it needs more gas, but of course without enough air the engine shuts down and the request is not pushed all the way through. so continuing scenario, I get my Jeep towed home, wake up the next day, wash her down and clean her up~ and then when I go to fire the engine, the ECU still requests the pump to pump extra like i mentioned, and the pump goes into hyper mode and eats itself up.

I know that's a really vague and maybe sounds like i have no idea what I'm talking about, but when it comes to ECUs, I am still a beginner definitely.
but without holding that scenario to the T- is there any scenario close to that that might be remotely possible?
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