More 3L problems....Get in here guys.....

[stieny]

So what's next fellas?

New fuel injectors are in and it's still running like crap, especially at lower/mid throttle. It's hesitating and possibly missing.

I'm at the end of my patience with this truck.

 

[barrys]

I feel bad for all the angst you're going through and all the time and money you're spending. You said you took it to a dealer mechanic. Maybe you just didn't get lucky with the tech to worked on your vehicle. Do you have any way to get recommendation to a really good, Ford only, independent shop? At the dealer, it's hit or miss. Some of those techs are the best Ford techs on the planet while others just got out of school. If you find some good indy shop that's been in business for 20+ years, they'll know things about your car you would not even imagine. Whenever I ask my guys about a repair, they start getting all deep about the original component desings, how they've evolved over time, how they workaround known shortcomings, etc. I just don't think any of us who are not professionals or even an average dealer tech is going to know all of that. Even if you have to drive a bit, it might really end up being worth it.

I don't know shit and you obviously are a better mechanic than me based on all the work you've done. You seem to know you're getting fuel in there now. You haven't mentioned doing a cylinder balance test (3 times) which can't hurt but might not help -- especially since it's a low RPM test. You might post pictures of your plugs so some guru can comment on that. I hope you get it all figured out.

 

[stieny]

I have not taken it to a dealer or a mechanic because I usually do all my own work on all my vehicles myself. Also, my dad was a mechanic when I was growing up and he knows and is friends with many trustworthy mechanics, all of which we have pulled ideas out of. At this point, I am at a wall. I have exhausted every option.

The only thing left is to take it into a dealer but since I've changed and checked almost everything and the truck isn't throwing any codes, I'm not sure what they are going to really tell me. I can see them throwing ideas out there and guessing at things just as I have been doing. Then in the end, I'll be stuck with a ridiculous service bill with no more real answers.

 

[richlands55]

With the truck running, unplug some of the sensors to see if it will set any codes.
You could have a bad computer.

 

[stieny]

With the truck running, unplug some of the sensors to see if it will set any codes.
You could have a bad computer.

I did that already too.

With it running, I unplugged the MAF just to see if it would trigger anything.

And it did, CEL came on just as expected.

 

[richlands55]

Have you tried spraying a water mist on your plug wires with it running
to see if it will miss? You might pull your plugs and recheck the gap. What brand of plugs did you use? Could be something simple as a plug or wire breaking down. It`s almost impossible to diagnose a vehicle without having it in front of you.

 

[richlands55]

I went back and re-read your post. If what i said before does not help, get a noid light to check your injector wiring to make sure they a pulsing the injectors.

 

[stieny]

Have you tried spraying a water mist on your plug wires with it running
to see if it will miss? You might pull your plugs and recheck the gap. What brand of plugs did you use? Could be something simple as a plug or wire breaking down. It`s almost impossible to diagnose a vehicle without having it in front of you.

I have pulled the plugs again. They all look fine and nothing is irregular between the 6 of them. They are Bosch and they are gapped at .44.

I have not done the water test yet for two reasons: One, they are a brand new set of wires. Two, I had a plug wire go out on me a few years ago and the symptoms were much different. I had a constant miss throughout the whole RPM range as the wire was arching on me.

This only seems to be really noticeable at mid/part throttle and much less noticeable at higher RPM's. It seems more like a stumble then a large miss. It was doing it before I replaced all of the stuff and seems to have gotten worse.

And it isn't even so much the stumble that bothers me the most. If someone said it's aged and it doesn't run as smooth as it one did, then fine. It's the fact that my daily commute is about 40-45 ALL highway miles and I'm only getting 11-15 mpg and it seems to be a very sudden drop.

I'm at about 85-90 miles and at about a quarter tank right now.

 

[stieny]

I went back and re-read your post. If what i said before does not help, get a noid light to check your injector wiring to make sure they a pulsing the injectors.

I was going to try to pick on up but I have pulled the plugs off the injectors while it was running and it sounds like its losing a cylinder. Not the best way to test it, I know, but pretty effective none the less...

Also, The plugs look like they are burning clean and I'm not throwing any lean codes but that obviously doesn't mean much as the truck hardly ever pulls a code.

But I do appreciate everyones ideas and suggestions. I'd really like to keep the truck if I can but I can't keep spending all this money on gas.

 

[barrys]

I was wondering when someone was going to chime in on the spark...
If you go to tousleyfordparts.com you can get the stock plugs for something like 2.41 each. They are motorcraft, single node platinum. Don't gap them. They come pre-gapped and we're not supposed to be gapping platinum plugs.

Also, dealer and great indy shop are not the same. At the dealer, it's crap shoot whether you get a good, seasoned tech. At a good indy shop, their reputation is more an issue so the best person there should at least be looking in. And, Ford only indy is the only thing I'm recommending. Unless your Dad or his friends are Ford experts, there still could be something they'd miss. Every brand has it's own wierdness and Ford is no exception.

 

[stieny]

Alright guys, I appreciate the ideas and it's something I can possibly look in to.

One question though: How does a spark plug (that's new, mind you), even though not a pre-gapped Ford plug, cause my truck to get near single digit fuel mileage on the highway?

It just seems like such a stretch.

 

[stieny]

Well, I filled up today. All highway miles, I got 13 mpg out of the last tank. And to think, this is just a little 3.0 5sp. That's horrible in my opinion. Especially because a month ago I was getting over 20.

So I am trying free things now since I've ran out of ideas. I swapped in another brand new set of wires to see if the hesitation was arching wires. No go.


What the hell....