7.3 no start/Pissed off wife

[svc]

Well I got the dreaded call yesterday! I am on my way to work. Wife calls and says "Looks like We are getting a new truck". Evidently my 2000 drove just fine up to the local sonics and then would not start. Towed it home and started checking things out. I could not see the rpms move while cranking so I quickly changed the cps and found no go. Checked fuel canister and oil resorvoir all are fine (recent oil change and filter replacement). Noticed the electric fuel pump came on about the third turn of the key and then started write up. I monitored several times trying to catch whether the pump was getting power and found each time the pump received power it ran. It seems the pump does not get power each time the key is turned on. I swapped the fuel pump relay with the windshield washer pump and no change. I thought the pump was suppossed to run 10 to 20 secs each time the key was turned on? Thanks for any help!

[svc]

What no takers?

[Austinj427]

Bad fuel pump? Did you check connections?

[dieseldan2005]

Wasn't there something about the fuel bowl heaters on those? There was a fuse for them and if it blew they wouldn't start. I can't remember if that was on just the obs trucks or if it was on the super duties too. It seems like more of the obs guys had that problem, but it might be worth looking at.

[Marty]

Fuel Pressure?

Looks like you already know what to look at if your not getting power at the pump.

[svc]

I was starting to get lonely. Thanks for the response. Seems the pump comes on randomly. Not every time you turn the key on. I cleaned the pump connections and checked power with my six year old turning the key on and off and found once the pump did get power it would buzz and I could hear the fuel running through the lines and then It will start and run with no problems. Just seems like I have a glitch with whatever controls the signal to the relay. I am currently trying to get a shop manual to look into this further.

[svc]

So does the pcm control the fuel pump relay? Is the pcm the box down by the drivers feet. What is the controller behind the headlight switch? IDM? Thanks for any help. Could someone also recommend a shop manual.

[chvyrkr]

Originally Posted by Austinj427

Bad fuel pump?

What he said ^^^

Originally Posted by dieseldan2005

Wasn't there something about the fuel bowl heaters on those? There was a fuse for them and if it blew they wouldn't start. I can't remember if that was on just the obs trucks or if it was on the super duties too. It seems like more of the obs guys had that problem, but it might be worth looking at.

Just OBS trucks.

Originally Posted by svc

So does the pcm control the fuel pump relay? Is the pcm the box down by the drivers feet. What is the controller behind the headlight switch? IDM? Thanks for any help. Could someone also recommend a shop manual.

Not sure what powers up the relay, probably simply the ignition switch.

However, when my fuel pump quit on me a while back we had "no power" to it. Test light refused to register any power at the conections to the pump. I replaced the pump on a buddies word that "no power" is common when pumps quit, and hadn't had a lick of trouble since.

The pumps ain't cheap, I know. But get yourself a decent fuel-line removal tool, (10 bucks max) and a pump, and hook up the lines and power wires without actually installin the pump in that bracket. Flip the key and I bet your problem is solved.

If it ain't disconnect the pump ,should still look good as new, and take it back to the parts store. No fuel should get sucked into it if the wiring is in fact the issue.

I'm bettin it's the pump though.

[chvyrkr]

So, I'm not electrically smart.

And it took it a very long time to hit me... But it just hit me.

There are two posts on that pump. So if the connection inside the pump between them don't connect (the pump is bad) then you won't have any power reading at the pump.

Right?

If the curcuit in the pump never closes, power never travels through it right? It never draws power because it won't draw power until the "circle is complete."

Your pump is bad.

Or I'm up way to late and babbling nonsense again.

Either way hang test a pump. You'll at least eliminate a piece of the puzzle.

[svc]

appreciate the response. But, it sounds like in your situation you might have had bad connections and depending on where you place your meter such as directly on the wiring or just on the connection will depend on whether you show power. There are 2 posts positive and negative. If there is power being sent through the relay then you will see power to the pump as long as there is a good ground. I could see if you were trying to pull amp draw that you would see no reading if the pump is getting power but not running. I think in my situation my problem lies with whatever controls the fuel pump relay. And since it is a timed sequence with the key on I am guessing the pcm. I know electrical well but do not have any info on this truck.