Okay guys, HELP, I'm going crazy.....Just bought a 1997 F-150 with the 4.2 liter V6. It's been great for the past two weeks. I took it to the car-wash, spray cleaned the engine while I was at it and noticed that the previous owner had a couple old spark plug wires mixed with newer ones etc. Decided to but a new set of wires. Drove the truck to the parts store, no problem. Drove from the store home. no problem. Got home, changed the wires...problem. Did not start. This was two days ago, and here's what all I've tried. But first, let me say that the engine turns over just fine. Sounds “ready” to start. Sometimes will “pop” from fuel detonation that blows out the front of the throttle body...not a “back-fire” more like a “front-fire”? Maybe a new term! Anyway, I suspected the coil pack, checked the primary and secondary resistance. The secondary resistance was close, but not quite on the numbers, so I replaced it. No help. Next, replaced, (and gapped) the plugs. No help. Next, I checked all 4 terminals on the wiring harness that goes to the coil. The positive terminal lit up nice and bright, but the three negative terminals were very very dim...hardly there at all. After reading in the manual for a while, I decided to replace the crankshaft position sensor. No help....New plugs, wires, coil pack and crankshaft sensor. As far as I know, the only electrical component left is the PCM. Of course it's the most expensive so I want to rule out any other possibilities first. Any help out there is greatly appreciated!!!!! Thanks!

 

sound like youre getting spark, but are you sure youre getting fuel?

 

Ok don't take this the wrong way.

Very carefully completely re-check your plug wires for fireing order. I read a post awhile back where a guy had almost an identical issue and did everything you did including handstands and swore the wires were right. In frustration he re-checked the fireing order and bingo. Being that it ran fine before the wires, go back to square 1.

Good luck

 

Thanks for the quick replies!, blackedoutV6, I do have fuel pressure, but that doesn't mean the fuel is being "injected" by the injectors, so I will check that!

jgger...I think you're on to something, let me explain. When I removed the old wires, I remembered thinking they did not seem to be in the correct order as the diagram. So I figured, with the wires reinstalled "correctly" that the truck would run better than ever! But of course this was not the case...now...I need to know how the wires were before...

As I understand it, the firing order is 1-4, 2-5, 3-6, but what I don't know is the order the spark sent from the coil pack. The posts on the coil pack for most all Ford V6 is 1-2-3 up the right and 4-6-5 down the left.

If there's another way to verify the proper wiring pattern, please let me know! Thanks all...:o

 

I'll have to look in my book, unless some body else has a picture.

 

Ok I looked it up.

Passenger side cylinders front to back 123
Passenger side of coil (terminal side) front to back 123


Driver's side cylinders front to back 456
Driver's side coil 564

fireing order 1-4-2-5-3-6

Hope that does it for ya.
Good luck.

 

Here's the top view of the coil pack. The wires are going to the plugs(cylinders) as pictured. Let me know if this looks right! Thanks!!<a href="http://s305.photobucket.com/albums/nn216/kerrye123/?action=view&amp;current=coil.jpg" target="_blank"><img src="http://i305.photobucket.com/albums/nn216/kerrye123/coil.jpg" border="0" alt="Photobucket"></a>

 

http://s305.photobucket.com/albums/nn216/kerrye123/<a href="http://s305.photobucket.com/albums/nn216/kerrye123/?action=view&amp;current=coil.jpg" target="_blank"><img src="http://i305.photobucket.com/albums/nn216/kerrye123/coil.jpg" border="0" alt="Photobucket"></a>

 

Looks like what I gave you. Any luck?

 

No luck yet, however, I'm beginning to think it's a fuel problem....there is a spark at the end of each plug wire, so if there's something to burn, well, it would ignite....maybe some water go into the gas, or the intake somehow? I say all this because (after checking the plug wires a million times) it does almost start sometimes...some small (fuel) ignition is taking place...Thanks!

 

If I recall correctly, the coil wires on my '99 driver's side went (front to back) 4 6 5. The driver's side cylinders (front to back) would be 4 5 6.

This is the same concept but a different order on the driver's side than jgger posted.

Sorry, don't have the truck anymore to check.

I doubt if you have a problem with the inertia switch. this is under the kick panel at the passenger's feet and is deisigned to shut the fuel off after an accident. There is a process for resetting it if it trips. But if your motor is almost starting, I suspect the plugs are hooked up wrong.

 

i have 05 f150 was working fine then just shut down spark ok no fuel ch fuse was blowed replaced and went again ch out module on rear chassis corroded and swollen up installed new unit and new fuse now eng wont crank plug in old module eng will crank but no start plug in new module eng wont crank any ideas

 

Huh? In English, please? Does this have anything to do with the original post?

 

the coil and wires are set up dirrently its not 123 456 on the motor and the coil is 123 on the drivers side and 564 from front to back

 

Okay guys….I never want to just leave a post hanging! I finally got the coil/plug problem solved!!! But it was not easy!!! First, let me say to all who’ve traveled this road before, a Haynes’s manuals can be wrong!! Well, maybe not wrong, but sometimes the right information is just not in there!……On this particular 1997 Ford F150 with the 4.2 liter V6, the manual will tell you, and even show you a diagram that lays out the coil to plug wire pattern. On the coil, from front of engine back to the firewall, passenger side, manual says 1 2 3 then, from front of engine back to firewall, driver side 5 6 4. BUT, THIS IS NOT RIGHT…at least not on my truck…The correct routing is front to back passenger = 3 2 1 then front to back driver side = 4 6 5 . If you compare this to what the manual says, it’s basically the same routing, just upside down….Now…how did I figure this out?....I didn’t….I called a mechanic who did a little research…he used the I.D. number on the engine block to get the information from Ford. Something about the transition from the 3.8 liter engine to the (Canadian built) 4.2 liter engine using much the same parts and engineering…or something…but to cut it short…some of the first crossover versions of this engine happen to use this “upside down” configuration…hope this helps someone else in the future!!! Thanks!