Heres my problem.Yesterday I was parked at a stop light when I felt this wierd vibration. I rolled down my passenger window and listened to my exhaust and definately heard something wrong. I sounded like a cylinder wasn't firing. I drove to work, called a mechanic , and waitied to get off work. When I started my truck it sounded normal and drove normal. I took it to the shop anyway and got it back today. The mechanic said that he couldn't find any trouble codes. I drove it back to worK and then home, all was fine. As I was driving from my house to the gym it started again. It sounds like a cylinder isn't firing. But it has only done this when the engine is completely warmed up. Any Ideas? I'm guessing its a bad coil. Thanks

 

How old, how many miles are on your truck? Have the C.O.P.'s ever been changed out? More info is needed here...

I just recently had an issue that sounds somewhat similar to yours: when the truck was good and warm- I would notice a loss of power, I could hear the engine "missing" or misfiring at idle, and it was running super rich. The more I plowed in any one night or day, and the hotter the engine got, the worse the problems got.

It wasn't throwing any codes at all, and the service techs could all see that something was definitely wrong but they couldn't pinpoint the issue.

We replaced coils, plugs, and a mass air flow sensor- no fix. They were also trying to tell me that it could be Tranny related, or possibly a fouled CAT.

The tranny was fine and the CAT was hollowed out from 240,000 miles of hard driving!

Finally I had had it and grabbed one of their master techs with his laptop and we went for a ride, when it was acting its' worst. He noticed some weird trends in the fuel flow and pressures.

So, we pulled the fuel filters and found them full of metal shavings. After 240,000 miles my fuel pump was finally going out.

Since the computer wasn't seeing consistent fuel pressures, it was demanding more fuel which in turn made the pump work harder- when it wasn't working well to begin with. That coupled with clogging filters provided an intermittent situation that was tough to diagnose.

It would help to know more about your situation/truck. Those coils do go bad, and they can act up intermittenly which really fouls with running any diagnostics.

You can also give your wiring harness a good look over- from the PCM to each injector/coil to make sure you don't have a chaffed wire rubbing somewhere creating a short-out situation.

Again, I am not a tech, I just know what I have been through...

Good luck!

 

according to dog if it is the fuel pump, y dont you just check your fuel filter for shavings?

 

YES! Start with the cheap and easy stuff first! If Ford "can't" give you any answers, I'd change out the filter- unless it's been positively changed recently of course- look over the wiring harness very thoroughly for any broken or chaffed wires, check out the C.O.P. boots and make sure that they aren't worn or cracked and letting moisture in...

One thing that drove me nuts is that I couldn't find a tech that could think "outside the box" well enough to troubleshoot the problems when the diagnostics programs were telling him that the truck was running fine! And I did some bouncing between Ford dealerships hoping that someone would figure it out.

The problem with that is that everytime you take it somewhere else- no matter how pissed you are at the last place- you end up explaining everything all over again to someone new, and they are going to start from scratch like everyone else... that all gets expensive.

With my rig, I finally stuck with one dealership. They had my truck for 4 days over the span of about 2 weeks. The truck never threw a code, and they never figured it out until I ground on them enough to let me take a tech for a ride. The truck was really pitching a fit, and of course the tech was shocked to see it running that poorly, when he had had it out the day before and it ran fine for him. He hooked up his laptop and that's when he saw some weird stuff going on with the fuel pressures.

We pulled the fuel filters and they were packed off with fuel pump parts...

It's pretty hard to say exactly what is going on with your rig based on what little info we have, but here were my trucks symptoms:
-the warmer it got, the worse it ran
-rough idle, sounded like it was misfiring
-rich exhaust fumes
-with the truck in Park or Nuetral, if I floored the gas pedal, it would start popping and backfiring at anywhere from 1800-2200 rpm's
-drastic loss of power (my wife went around and outran me in her Hyundai Santa Fe one night... that was the last straw- and in an unrelated story her car had four flats the next morning!)

I originally thought that I had a couple of coils go bad- I've had that a couple of times over 240,000 miles... and if you determine that that is the case, stick with Ford OEM C.O.P.'s. For some reason that triton doesn't like anyone else's coils.

I know it's a bit long winded but I hope it helps some.

Good Luck

 

cheap is gewd.

 

Could be a bad plug or two.

 

I just changed the plugs about 7,000 miles ago. Ditto with the fuel filter. I haven't changed the COPs yet. I've only got 64,000 miles. There is no backfiring. Just a real goofy sound like its misfiring. I think I'm going to change the COPs today and see if that helps. Thanks for the info.

 

Just because they are new does not mean they have not gone bad. I had two plugs go bad on new GM engine at 5,000 miles. Have them tested-cheap fix.

 

I just bought a fuel pressure tester. I'll start there first since the COP cost $82 a pop.

 

Which plugs did you put in your engine?

 

I used NGK V-powers. I checked my fuel pressure and it was good to go. I think I'm going run my tank until its empty and fill up and see if that fixes the problem.

 

[QUOTE=beefeater]Just because they are new does not mean they have not gone bad.QUOTE]

I went back to OEM motorcraft plugs after a bad spell with some other plugs a few years ago, and of course Ford just told me that those Tritons were finicky like that- no rhyme or reason, but that V10 just prefers to run with ford parts.

The same goes for those coils. The Ford coil is not cheap, but when I tried to replace my set with a "hotter/cleaner" aftermarket set last year, I burned up 6 out 10 in less than 1,000 miles. I got my money back but the time lost and frustration gained just isn't worth it!

Good Luck with thos ecoils, and keep us posted.

 

After all the wisdom here in the V10 forum you still used plugs that arn't Motorcraft or Autolite, shame on you.

 

Try filling at a different station. Maybe bad gas?

 

No help here. I'm on the original plugs