Hi guys, I have a no fuel problem with my 06 Ranger, 4.0 auto 4WD, Just put the motor back in after doing the timing cassettes and she won't start. Really thought it would be a wiring thing that I missed but everything seems OK and I think my grounds are good. Read a bunch of threads on it and I just want to be sure I cover all bases before dropping the tank. Zero pressure at the rail, can't hear the pump wind up, did the relay swap, starts and dies with a shot of starter fluid so I have spark, disconnected the inertia switch... When I turn the key to run I get 12 + volts for 2 seconds at the inertia switch, then it drops off. Bypassed the switch, and still no love. If I'm getting voltage past the switch, are there any other stops on the way to the pump? Also, What stops the voltage being sent to the pump? I always thought the pump stopped because it reached pressure. If it is pressure then maybe it's the fuel filter which I'm going to check next but I don't hear the pump. Any advice would be great, you guys kept my 96 F150 on the road for a long time.

 

Use your ELM scan tool, or the like to scan the ECM for trouble code clues & post All code Numbers as they can help focus a trouble shoot, in case you have more than one problem.

Were you having this problem Before the engine work? Seeing as how you have B+ at the inertia switch, (you didn't say on which side you measured B+) so if you didn't measure B+ at the output side of the inertia switch, try thumping the switch to cause it to trip. It's little post will pop up when it trips, then push it down to reset it in a new electrical contact position in case your getting a under load voltage drop through the inertia switch & make sure you have under load B+ on the Output side of the inertia switch. If so & no joy hearing the fuel pump run, try smartly thumping the fuel tank bottom with your fist, to wake up the pump, or try a stick to reach in & thump, or wiggle the electrical connection atop the tank & see if it'll wake up.

The 2 second run time at KOER is timed by the ECM & is normal to prime the fuel system for the start.

If you get the pump to run but still have starting, or run problems, use your fuel pressure gauge to check fuel pressure & volume over time, at the under hood fuel rail Schrader valve test port & post the Numbers.
Fuel pressure should be 64 +/- 8psi & volume should be something like 1/2pt - 15 seconds pump run time, so you'd have to cycle the ignition switch 7-8 times, or power the pump from the inertia switch output wire with a 12 volt source for 15 seconds.

If you come to believe the pump is kaput, its said by those that have replaced the pump, that it's easier to move the bed back than dropping the tank to replace the fuel pump.
On moving the bed back, remove the tail gate to make the bed lighter. Disconnect the tail light wiring connector & fuel fill tubing, then remove the bed bolts & move the bed back to sit on the rear tires & saw horses, so you can access the pump atop the tank without having to disconnect the fill tube, drain & drop it.

A bunch of thoughts for consideration, let us know how it goes.

 

Thanks for the help PawPaw. Haven't seen any codes yet. I bought the truck from a coworker who's mechanic told him it was the timing chains and he didn't want to spend the money. The rear cassette was luggage so I thought his mech was right and I'm going to be good to go. Starting to wonder if the pump was his problem in the first place. No matter, just some history, going forward.

At the inertia switch, I have 12.8 volts for a couple seconds, then it drops off. The connector was a little cooked so clipped it and read both sides to find out which was which. I just wire nutted to bypass the switch, no luck. I wondered about sending 12 volts straight thru to the pump... I'll be sure to send the 12 volts towards the pump... I haven't done the tank bump yet but I will try both today.

I like the tip on sliding the bed back, did some recon reading threads on that too.

Thanks again, I'll let you know how it goes.

 

The inertia switch connector looking a little cooked may be a clue to suspect the fuel pump, or a voltage drop wiring problem to it. So if you can get the pump to run, use your multimeter to measure for voltage drop & current draw at the inertia switch. as its easy to get at for testing & you can determine if the voltage drop is because of a problem in the pump, or wiring run to it.
Like the inertia switch internal contacts being cooked, or maybe a problem with the under hood power relay, or its power distribution box contacts being corroded, or cooked & causing a under load voltage drop from a faulty pump drawing too much current, or the like. Anyway make sure the fuel pump B+ feed & ground wires & connections are in good shape, including its fuse contacts, clean bright & tight, so you know the circuit is ok for a new pump if you have to replace it. Make sure someone hasn't over fused the pump. Your owner manual will specify the right value fuse.

 

Were you having this fuel pump no run problem Before the engine removal?

 

Don't know if the no fuel existed before the engine pull. Took the mechanics word that it was the timing chains and read up on that. Tried to start it to move it but some info said running it could do more damage so I just pulled the engine.

So she may have been running okay on the broken rear cassette but lost the fuel pump, don't know. Again, I really thought that with the engine in and out that I missed a connection or a ground or something but at this point, having 12v at the inertia switch, I'm trying to rule out a bad pump. The 12 volt direct connect should prove that one way or the other. If the pump spins up, then I'm chasing connections. If no, Then next step is R&R the pump. Well, slide the bed back first. Haha

Raining out pretty good right now so maybe later today or tomorrow. Thanks

 

A little no fuel update. I determined which wires at the inertia switch were B+ and out to the pump. Hooked my jump pack towards the pump and she wound right up. Reconnected the jumper at the inertia switch and started the truck... ran very poorly for a few minutes and died but ran long enough to pull 2 codes, P171 and 174, lean banks. Tried to start again but no go, checked my voltage at the inertia and got zero.

So now I'm chasing connections. Remember my inertia connection was a little cooked. Checked the 20 amp mini fuse in the power distribution box and found it loose as a goose. Pulled the outgoing wire and made up an inline fuse link to an available B+ terminal, taking the bad socket out of the mix. Also I trickle charged the battery overnight just to be sure.

I have my meter clamped to my jumper at the inertia switch so I can monitor the voltage while I turn the key. Key on I get 12+ volts for 2 seconds and then it drops off. While turning over I get 12+ volts continuously but no start and no pressure at the rail. Again with the jump pack, disconnect the jumper and send current directly to the pump for 10-15 seconds. Winds right up, 60+ PSI, disconnect the pack, pressure falls right off, reconnect the jumper and she starts again, running poorly and again, the same 2 codes P171 and P174... 12+ volts at the inertia jumper and zero pressure on the gauge at the rail while running.

Next I guess is to pull the bed and check the voltage at the tank.

Anything I'm not doing, I did replace the fuel filter, or is it time to replace the pump? $309 at Tasca $263 at Rockauto

 

Swap the fuel pump power relay for a known good like one not needed to start or run the engine & see how it goes. If the old relay was having to deal with voltage drop through its contacts from a loose fuse, they might been over heated & oxidized & not making a good electrical connection that's dropping under load pump voltage too.