I tried restarting the truck and all it would do is turn over?

Tiny
JOHN JONES4
  • MEMBER
  • 2004 FORD F-150
  • 4.6L
  • V8
  • 4WD
  • AUTOMATIC
  • 280,000 MILES
I have the truck listed above Heritage that won’t start. I was going to work last week and it shut off while driving like the key was turned off. I tried restarting the truck and all it would do is turn over. I have replaced both cam and crankshaft position sensor and the fuel pump. All fuses and relays are good and have power. I still have no fuel pressure, 1.53v crankshaft and signal from camshaft sensor when engine is turned over or with key on. Theft light is not on and check engine light goes out when you try and start the truck. What am I over looking?
Wednesday, March 10th, 2021 AT 5:00 PM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Hi,

Have you checked fuses and the relays? This vehicle has a fuel pump relay and a fuel cut relay in the event of an accident. Both are located in the aux relay box. See pic 1.

In pic 2 below, I highlighted the fuel pump relay fuse. Check to make sure the fuse is good and there is power both in and out from the fuse. This is the fuse box under the hood.

Here are a couple of links you may find helpful:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

https://www.2carpros.com/articles/how-to-check-a-car-fuse

_______________________________

Let me know what you find or if you have other questions.

Take care and God Bless,

Joe
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Wednesday, March 10th, 2021 AT 6:45 PM
Tiny
JOHN JONES4
  • MEMBER
  • 5 POSTS
I have checked all fuses and relays all are good and all have power going to them. I have power to coils and injectors as well with only 1.53v to cranksensor. Should I not have battery voltage to the cranksensor?
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Wednesday, March 10th, 2021 AT 9:22 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Let's start at the beginning. Do we have spark and fuel to the engine?

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Let me know.

Joe
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Friday, May 14th, 2021 AT 8:33 PM
Tiny
JOHN JONES4
  • MEMBER
  • 5 POSTS
I have fuel pressure and injector pulse but no spark. I have 12 volts at cops. CMP, CKP, and fuel pump assembly are all new and computer has been tested and is good. I plan on trying to look and see if igniter ring is intact tomorrow. The question I have is this, if it jumped time would that cause it not to fire even tho the CKP sees the igniter ring?
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Thursday, May 27th, 2021 AT 3:50 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
The crank sensor is new, but that doesn't mean it isn't bad. If you have a live data scanner, you can use that to see if there is an RPM signal. If there isn't, I would try a different crankshaft position sensor.

Here is a link to help:

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

The attachments below are specific replacement procedures specific to your vehicle.

Let me know.

Joe
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Friday, May 28th, 2021 AT 4:11 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Hi,

Okay, if I am reading the schematics correctly, the coils have power at all times, but the ground is provided by the PCM. That is what would actuate the coil to fire. Take a look a pic 1 below.

I highlighted everything with the coils. Note there is a red/lt green wire that I circled. That is coming from the central junction box and should have power and should have power when the key is in the start or run position. Check for power and let me know if it's there.

The remaining pics include the entire powertrain management wiring schematics. I had to cut them in half to make them readable, but I did overlap them so you can follow from one to the next. I wanted you to have them as a reference. Additionally, I highlighted all the wiring to the PCM from each coil. All highlighted wires are tied into the coils and power to them. Since power is coming from the red/lt green wire, the PCM must be providing a ground path. That is why I'm suggesting checking that wire for power. If it isn't there, we need to see where it's lost. If it is there, we need to move to the PCM.

I remember in one post you indicated there is power to the coils. I want to confirm that is the wire you checked.

Let me know.

Joe

See pics below.
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Saturday, May 29th, 2021 AT 10:24 PM
Tiny
JOHN JONES4
  • MEMBER
  • 5 POSTS
I have power to the coils but it is not battery voltage. It starts at 5.0 volts and drops to 1.5 volts. But I have power on both wires to coils.
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Saturday, June 5th, 2021 AT 1:25 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Hi,

You shouldn't have power on both wires. One is power, the other is open until the PCM provides a ground path. Also, the voltage shouldn't drop. Were you able to locate the splice I mentioned? When you have a voltage drop when under a load, it's usually a faulty connection.

If you look at the pic below, it shows the splice I'm referring to. Also, go back to the central junction box, locate the red wire with a light green tracer, and see if there is 12v there. See pic 2 below.

Let me know what you find.

Joe
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Saturday, June 5th, 2021 AT 8:36 PM
Tiny
JOHN JONES4
  • MEMBER
  • 5 POSTS
Joe, thanks for all your help. That wire was the culprit. About three inches from the engine harness connector the wire was chafed into it had been rubbing against the accumulator. Again thanks for all your help.
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Tuesday, June 15th, 2021 AT 7:35 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
Hi John, I'm glad to hear you found the problem. Electrical issues can be difficult.

Regardless, if I helped, you are very welcome. Please feel free to come back any time in the future. You are always welcome here.

Take good care of yourself.

Joe
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Tuesday, June 15th, 2021 AT 10:33 PM

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