2002 F150 4.2L crank and no-start

[92saturnsl2]

Helping a co-worker diagnose his non starting (but healthy cranking) 2002 F-150 4.2L w/ 220K. It began by working intermittently (but never left him stranded), seemed the colder the weather, the more problems he had on initial start. He took it to a local-yokal mechanic who charged him to clear "security codes" and suggested he take it to a locksmith to have his keys reprogrammed as he says this is a common problem when keys lose their programming. That sounded a bit odd to me, so I offered to help. This was my ginuea pig for my first use of Forscan and I didn't see any issue whatsoever with keys or security system. Even went through key reprogramming.

This is what I observed:

Starter cranking just fine, nothing odd with the theft light, it comes on with turning the key to ignition and promptly goes out.

Using my scan tool to command the fuel pump ON, there is no output from the fuel pump but the relay DOES engage. I verified power to the relay output terminals. Go to the fuel line and press on the valve at the rail, and there is zero pressure in the fuel system.

Pretty sure this is enough to condemn the fuel pump at this point, but his "mechanic" insists that faulty keys will not allow the fuel pump to turn on. My logic is that if the fuel pump relay is engaging when the pump is commanded on through a scan tool, it should be working.

Any thoughts?

 

[zrxkawboy]

Your reasoning makes sense to me.

 

[bullwinkle]

Any chance of an infamous Ford "rollover/inertia switch" on that truck? That'll kill an FP deader than a doornail! It's behind one of the kick panels, the owner's manual should show how to reset it. Or maybe the fuel pump is bad...

Fuel Inertia Switch Reset - 2002 F150 - Ford Truck Enthusiasts Forums

1997 - 2003 F150 - Fuel Inertia Switch Reset - 2002 F150 - 2002 F150 XLT with a 4.2L Once before I had to reset my my fuel inertia switch on my truck. The switch is under the passenger side kick panel like most of the internet says for my vehicle but . . . It doesn't have the big red button (or...

www.ford-trucks.com

 

[clinebarger]

Any chance of an infamous Ford "rollover/inertia switch" on that truck? That'll kill an FP deader than a doornail! It's behind one of the kick panels, the owner's manual should show how to reset it. Or maybe the fuel pump is bad...

Fuel Inertia Switch Reset - 2002 F150 - Ford Truck Enthusiasts Forums

1997 - 2003 F150 - Fuel Inertia Switch Reset - 2002 F150 - 2002 F150 XLT with a 4.2L Once before I had to reset my my fuel inertia switch on my truck. The switch is under the passenger side kick panel like most of the internet says for my vehicle but . . . It doesn't have the big red button (or...

www.ford-trucks.com

X2

 

[92saturnsl2]

X2

I'll have him check the inertia switch but I'm skeptical since the problem was intermittent for a time until it will no longer start.

 

[clinebarger]

Just check for 12vdc at both pins at the inertia switch with the relay commanded on.

With a test light/power probe.....You should get a ground return through the pump motor windings (relay off or removed)

Have you tried banging on the tank? If it starts put a fuel pump in it.

 

[Warstud]

Fuel pump was my first thought then you said it was worse in cold weather . Try some starting fluid

 

[Nukeman7]

I'll have him check the inertia switch but I'm skeptical since the problem was intermittent for a time until it will no longer start.

I had a similar problem on a 2003 Ford Ranger where the fuel pump would cut out intermittently and magically restart a few minutes/hours later. It turned out to be a loose connector on the inertia switch. Somehow, a tall passenger stepped on the wire bundle feeding the switch in the kick panel and dislodged the gray plug enough to cause intermittent contact. It finally became fully dislodged a few weeks later when I was 40 miles from home. I'm sure glad that my buddy had AAA premium towing.

You can see the gray connector plug in the bottom of the inertia switch at 24 seconds into the video below.

 

[JWC86]

Sounds like you’re heading in the right direction. I would check power directly at the fuel pump next and go from there.

 

[92saturnsl2]

Update: My co-worker called his local-yokel shop back and gave him an update that we reprogrammed keys which changed nothing and that we [mostly] narrowed it down to the fuel pump. The guy responded by saying it's probably a bad cluster or something under the dash, because he was certain the codes he cleared that were related to anti-theft were the cause of the problem. He insisted that the security system "problems" were keeping the fuel pump disabled. I was skeptical all along because I'm fairly certain these anti-theft systems won't allow the starter to engage.

In frustration, said co-worker tried it again the day after I was there and got under the truck and tapped the fuel tank with a rubber mallet while his wife turned the key on and off to prime. He could hear the fuel pump kick in for about a half second, then quit. He recorded it on a video and showed it to me, and I agree with him. I should also note that I had him check fuel pump fuse and inertial switch and both were fine.

He called another shop and they agreed it's likely the fuel pump and are charging him $250 for labor, if he supplies the part. I live too far away for him to have it towed here, otherwise I'd help him out.

 

[92saturnsl2]

Quick update-- replacement fuel pump did the trick.