2000 ford f350 6.8 two speed fuel pump resitor
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Topic: 2000 ford f350 6.8 two speed fuel pump resitor
Posted By: HudCo
Subject: 2000 ford f350 6.8 two speed fuel pump resitor
Date Posted: 27 Sep 2021 at 6:08pm
| can not locate ford pn. f81z14a601ac , data shows it under or around power distrubtion box under hood but with all of that removed i have not found it yet. |
Replies:
Posted By: fixer1958
Date Posted: 29 Sep 2021 at 6:08am
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Define '2 speed fuel pump'. Never heard of it on one of those. I looked up the part # and I don't know what it is. You have a fuel pump relay that is in the center of the dash behind the ash tray kinda. 3 relay box. Should be upper left. That's all I got.
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Posted By: jaybmiller
Date Posted: 29 Sep 2021 at 6:40am
 Google found it (208 hits )!..at least NOW you know what you're looking for. My gut tells me that maybe the 'computer' runs pump at full power until backpressure is 'seen', then reduces power(puts resistor in series) as it's not required ?? ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: fixer1958
Date Posted: 29 Sep 2021 at 7:27am
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I saw that. That's not how it works the way I know it. Fuel pressure regulator is on the fuel rail, vacuum controlled. |
Posted By: steve(ill)
Date Posted: 29 Sep 2021 at 7:52am
Not used on the standard F150..... used on the supercharged engine only... Sheet does list the F250-450 models, but very little data on why ? On the F150 supercharger, it is in engine compartment near the fuse box. ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 29 Sep 2021 at 7:57am
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some talk of use on the F150 supercharged.... i think when it says "duel fuel pump"... there are actually TWO FUEL PUMPS to deliver more volume under full throttle condition. https://www.f150online.com/forums/lightning/496551-dual-fuel-pump-resistor.html" rel="nofollow - https://www.f150online.com/forums/lightning/496551-dual-fuel-pump-resistor.html ------------- Like them all, but love the "B"s. |
Posted By: fixer1958
Date Posted: 29 Sep 2021 at 8:13am
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The newer engines per GDI and turbo have a fuel pump in the tank and a very high pressure pump situated on the intake usually that is run off the cam. No injector rail. Fuel is injected into the cylinder versus above the intake valve. This is an 2000 F350. No rocket science here. Built for work not necessarily go fast. |
Posted By: steve(ill)
Date Posted: 29 Sep 2021 at 8:21am
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YEs... i have a 2013 TURB motor and it has a mechanical fuel pump ( injection pump) at the motor ( Direct Injection like a diesel -- not into the manifold)............... the above RESISTOR was used on the 2000-2004 SUPERCHARGED F150 engine........... and for some reason on the F250- 450 motors (???)
------------- Like them all, but love the "B"s. |
Posted By: Brian Jasper co. Ia
Date Posted: 29 Sep 2021 at 8:23am
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In all of my years as a Ford dealer tech, never came across a two speed fuel pump on anything. A 2000 uses a return style fuel system with a pressure regulator and a simple constant speed pump controlled by a relay. When they did away with the return line and regulator they added a rail pressure sensor and a fuel pump control module that varies pump speed to demand. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: steve(ill)
Date Posted: 29 Sep 2021 at 8:26am
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your right Brain... thats how 99.9% of the F150s worked... The resistor was used with dual fuel pumps on the LIGHTNING SUPERCHARGED motors......I still dont know why the resistor was on the F250- 450. ------------- Like them all, but love the "B"s. |
Posted By: fixer1958
Date Posted: 29 Sep 2021 at 8:29am
You still have a fuel pump in the tank also. Some Ford references get a little skewed sometimes. Brian would know more than me if he worked at a dealership. I just know what I have come across.
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steve(ill) wrote:Posted By: steve(ill)
Date Posted: 29 Sep 2021 at 8:31am
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YEs.... the TURB motor has an electric pump in the gas tank and a mechanical driven INJECTION pump on the motor for Direct Injection into the cylinders.... Suppose to be more efficient than manifold low pressure injection. ------------- Like them all, but love the "B"s. |
Posted By: HudCo
Date Posted: 29 Sep 2021 at 9:26am
| its a good part # listed for the vin number at the ford store, and it is shown in the the wire schematic for that vin one pump in the tank . it gets 85 psi fuel most of the time some times it will go down to 30 psi and stay there . gets code p0232 on its fourth pump sinse febuary plenty of gas filters third regulator fuel lines and tank have been cleaned and flow with no restiction, alldata and idendifix show the restisor under power distubution box but with most of the componants removed on the left fender it aint there . if you command the pump duty cycle with the scanner when you get it down to 70% to 60% it wil just go from 65psi to 0 and kill the engine |
Posted By: HudCo
Date Posted: 17 Nov 2021 at 10:37am
| just had a 99 f 250 v10 at the shop this morning and the two speed resistor was there where its supposed to be . i am still working on this f350 v10 now it gets 80 psi as soon as you start going down the road all of the fuel lines have been ceaned cleared and checke you can blow bubbles in the tank form the regulator with 1 psi have tryed three differant regullators brands still have not located this resistor to replace it or the wire harnass . the f 250 had it mounted under the power distubution box and that is where are data said it is supposed to be |
Posted By: Les Kerf
Date Posted: 18 Nov 2021 at 6:40am
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Since you have been unable to visually locate this resistor perhaps you can try to find it by using logical electrical troubleshooting methods. If you have access to a decent schematic you should be able to test with an ohmmeter to determine if the resistor actually exists in your particular system. A resistor is a 'dumb' component so it should show up readily in the circuit if it actually exists (which it may not). A working knowledge of DC parallel circuits is also needed. Naturally, one should always observe proper care by disconnecting batteries, etc. |
Posted By: HudCo
Date Posted: 18 Nov 2021 at 10:47am
| have been back probing the pcm and the power distribution box. the low speed relay in the power distribution box has a diode in the unused spot in the box by the pcm diode main fuel pump relay is behind the radio i am going to call the man that was here yesterday and see if he will let me look at the bottom of his 2000 f250 and see if i can back probe his relay a freind of mine that runs a very bissy shop about 15 miles from us was in the ford dealership as a tech for 25 years during that period and he had never seen that ether |
Posted By: jaybmiller
Date Posted: 18 Nov 2021 at 10:50am
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FWIW... diodes are used to allow current (power) to go one way. This keeps a circuit from 'backfeeding' some other thing. ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Les Kerf
Date Posted: 18 Nov 2021 at 6:03pm
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Okay, now we are dealing with diodes which are active components, unlike 'dumb' resistors. It is very important to only use meters with high input impedance on these computerized systems so as not to overload the circuitry. A proper schematic is vital for analyzing this stuff. A known good system to use for comparison testing is very helpful. Good luck!  |