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Oct 23, 2013 | 07:12 PM

#31

pdqford

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Joined: Jan 2001

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From: Central NYS

Quote:

Originally Posted by alloro

Yes but the end result is the same, sensors, ignition coils, fuel injectors, etc. all lose power.

The coils are not powered by the PCM Power Relay, but items powered by the PCM relay, like the injectors, would lose power, as you pointed out, IF the PCM Power Relay was powered down.

But the PCM Power Relay is controlled by the ignition switch, so I don't follow the ASD concept with Ford.

Now in Mother Mopar, the ECM controls the ASD relay and can AUTOmatically Shut Down injectors, coils, O2 heaters if it doen't see a CKP sensor within 2 seconds of KO.

Anyway, let's see if we can help Danny get this rig up and running

Oct 24, 2013 | 12:07 PM

#32

Danny01Expo

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mini update, the security light goes off in about 3 seconds and i can hear something up front change
like an actuator or something. Read a post here about someone who changed their
fuel p-++-+ump without fully dropping the tank, i see there is some room there..

debating on doing the change myself or letting a guy off CL do ti for $100 he says he has the tool too. I guess
i'm about to climb under there and see if i have access to wiring to see if it's getting any juice and ground.

Some post had a couple of other ideas, putting an external fuel pump near the fuel filter (i think)
because the stock pump doesnt' inhibit flow, (and the other said he can't cut a hole in the floor,
didnt' say why).

After looking i see the fuel pump is located on the inside of the frame rail a little inconvenient.
Looks like there used to be an access door at the factory that they welded up near the pump.
. Darn.

Oct 24, 2013 | 03:34 PM

#33

pdqford

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Joined: Jan 2001

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From: Central NYS

Before you drop the tank, did you try what Fourty03 talked about in post #20 above?

Maybe keep your finger on the Fuel Pump relay while someone cycles the ignition key to see if you can feel it click.

Or you can porbe the IFS switch in the kick panel with your meter to see if voltage is available for the fuel pump prime when someone cycles the key.

If you don't have voltage here - pump won't run, and you are going in the wrong direction.

If you have voltage here and the pump still doesn't run, then drop the tank.

Oct 25, 2013 | 01:41 AM

#34

Danny01Expo

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Quote:

Originally Posted by pdqford

Yep. I was getting a slight 12v and a decent 5v.. and I was getting concerned.. I put 12V to the switch before and after, and the green and the somethingn/pink wires and it didn't make the fuel pump come on.

One thing is that even though I was sending it 12v at the switch,
I suppose it could have a bad ground, or a break in the wire
before it gets to the pump.

Looks like tomorrow I'll be jacking the truck up, putting it on stands,
and actually getting to the pump itself, check for ground, and 12v, and replacing
the inner motor, if that's what it is.

I'm going to pull up the rear seat first, because there's some kind of electrical equiptment moutned there, probably for the strobes or radio communication though.. it keeps the seat from coming up
so I have to unbolt it.. but i'm curious to what the device is and what it's worth. Then i'll have a look at that access panel, there are 2 bolts on it, and i'm wondering what's bolted there.

I'm hoping i can cut it open and get to the pump though. If not, under the truck I go. Hope it wont' be too cold outside.

Oct 25, 2013 | 03:55 PM

#35

pdqford

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From: Central NYS

Quote:

Originally Posted by Danny01Expo

Yep. I was getting a slight 12v and a decent 5v..

Could you elaborate on what a "slight 12v" means? And where were your meter probes?

And where did you get the "decent 5v"? And where were your meter probes?

Be aware that the green wire is only going to have voltage when the PCM pulls the fuel pump relay coil to ground, so when you turn the ignition switch to "ON" it will only energize the green wire for about 2 seconds to prime the pump.

Quote:

Originally Posted by Danny01Expo

and I was getting concerned...

Concerned about what?

Quote:

Originally Posted by Danny01Expo

I put 12V to the switch before and after,

I'm guessing what you mean is that you jumpered a 12v source to the IFS. Was the IFS disconnected so you could acess the IFS pins with the jumper wire? Or did you back probe the IFS connector with your 12v jumper while the IFS was connected? Please elaborate.

And before and after.....what?

Quote:

Originally Posted by Danny01Expo

I put 12V to the switch before and after, and the green and the somethingn/pink wires and it didn't make the fuel pump come on.

Putting 12v into the green/yellow stripe wire is just going to feed full 12v back into the PCM

12v into the pink wire should make the pump run (if the pink wire is has continuity all the way to the pump motor).

Quote:

Originally Posted by Danny01Expo

One thing is that even though I was sending it 12v at the switch,
I suppose it could have a bad ground, or a break in the wire
before it gets to the pump.

Now your cooking.

Strangely enough, the fuel pump is grounded up on the radiator support by the coolant tank.

Oct 25, 2013 | 05:49 PM

#36

Danny01Expo

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The test light i had, had led's for 5 v and 12v and the 12v lit up somewhat briefly,
so i was slightly concerned at first. Anyay I probed the IFS wires with it connected and disconnected. I fed 12v to both wires individually knowing of them should go to the fuel pump. Still no dice.. but at least I believe everything up to the IFS is good.

I didn't get a chance to work on it today, so hopefully tomorrow.

Oct 25, 2013 | 08:32 PM

#37

pdqford

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From: Central NYS

Quote:

Originally Posted by Danny01Expo

The test light i had, had led's for 5 v and 12v and the 12v lit up somewhat briefly,

Oh, one of those logic probes, eh?
At least having the 12v appear at the IFS for a brief time is the PCM turning the pump on for the 2-second prime.
Not sure where that 5v is coming from you mentioned in a previous post. Once the PCM shuts of the fuel pump relay after the prime that pink wire should drop to 0 v.

Quote:

Originally Posted by Danny01Expo

.. but at least I believe everything up to the IFS is good.

Agreed.

Oct 26, 2013 | 05:51 PM

#38

Danny01Expo

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OK so there is a new development, after the security light goes out at the 3 second
mark, i heard some noise at the fuel tank. I'm presuming the fuel pump is priming.
I know it could be weak, clogged, old gas, or clogged fuel filter.

I see it's time for me to invest in a fuel pressure gauge. Maybe i'll get lucky and it'll be a clogged fuel filter.

At least i didn't go through the hassle of dropping the tank yet.

Any recommendations oh where (pepboys, autozone, advance, are all local) to buy a FP gauge and which ones you like or avoid?
(and filter for that matter)

*** update ** no fuel pressure, not even pushing fuel into the filter. On to the fuel pump I guess.

*** update2** the sound i'm hearing isn't the fuel pump.. and i'm wondering if this skid plate is holding the tank up.. and the drive shaft is in the way of getting to one of the bolts..