loss of power no one can tell me what's wrong

[Gumbyalso]

I agree with Trainmaster about diagnosing. I have done a good deal of "diagnose by replacement". Sometimes you get lucky and sometimes it's a royal waste of money. I had a similar issue on my 2000 Expy 5.4 on hills only. It was over 290K and I had the original coils. Changed plugs and coils and problem went away. My son's '07 F150 4.6 had the same issue - only hills. I started down the list of possible culprits based on the codes by doing the cheapest and easiest first. First I cleaned the MAF. No change. Then I bought the right upstream O2 sensor and the fuel rail pressure sensor. When I pulled the old fuel rail pressure sensor I saw that o-ring had separate into two torn o-rings and knew that was almost certainly my issue. Since I had already bought them I replaced the fuel rail pressure sensor and the O2 sensor anyway, but I would say with 95% certainty my problem was a $1 o-ring. (The closest hills of decent size are at least 85 miles so test driving after just replacing the o-ring was not practical.) The problem was now gone and has stayed gone. You have to put a little lube on those fuel rail pressure o-rings or they will tear when you seat the sensor. Are any of these going to cure bobross' problem? I have no idea. I just got lucky. But if I'd taken it to a dealer they would have charged me more than twice as much as what both the O2 sensor and fuel sensor cost just to diagnose the problem. And I'll bet they would have managed to find something a lot more expensive wrong than a $1 o-ring that took me 5 minutes to change. That said, I did chase a vacuum leak on the 2000 Expy for about six months at around 200K. I changed plenty of hoses, valves, and even the brake booster because I was convinced they were the source of the leak. They weren't. I finally took it into Ford for analysis. Turned out to be a crack in the intake manifold back near the firewall where I never would have found it. Friggin plastic intake manifolds... The 2000 Expy has 315K on it now.

 

[GaryB]

Anyone consider diagnosing the problem?

Or you can change the plugs, boots, coils, variable timing sprockets, timing solenoids, chains, chain guides, catalytic converters, oxygen sensors, cam sensor, air and fuel filters, pcv valve, purge solenoid and a whole bunch of vacuum hose and see if that helps.

Not to hijack the thread, but this is exactly where I want to grow as a DIY/Shadetree mechanic. Anyone can swap parts. With the horror stories I hear about the average mechanic, I think many are parts swappers.

 

[bobmbx]

Not to hijack the thread, but this is exactly where I want to grow as a DIY/Shadetree mechanic. Anyone can swap parts. With the horror stories I hear about the average mechanic, I think many are parts swappers.

Thats the genesis of boards like this one.

 

[Trainmaster]

A big problem with swapping parts these days is that so many new parts are bad from the factory. Now you have the possibility of interjecting new problems into your search for the cure.

 

[Anthony A Vialet]

ford owner dot com there was some kind of service advisory that came up on my 2013 that involved the tranny oh (field service action) the is a reprogramming update some restrictions apply, vehicle mileage must be under 150k and the recall expires at the end of this month

 

[stamp11127]

Been a month since the op replied to this thread. It is probably another one where they go "****" and disappear.

 

[Tee Celly]

this might help the original poster...had the same issue a while back, turned out to be weak coil packs. replaced all eight and no more problem.

 

[TobyU]

Original coil packs? I'd start there, it's a pretty common complaint in the F150 world. The coils can go bad and not show any outward physical signs of failure. A blinking engine light means cylinder misfire, if it were me I'd be changing out all the plugs and coil packs. Use oem Motorcraft spark plugs, but I've had good luck with some of the cheaper brand coils on Amazon or ebay. Usually 1 in 8 will be bad out of the box or close to it so don't toss the old ones as you might need a spare while you warranty one of the new ones. How often do you change your oil? Long OCIs mess with the VCT solenoids and clog their screens. When they go bad, all sorts of power related issues crop up as well as noises. Hopefully you're changing oil every 5k miles with either Motorcraft 5w30 blend or a quality synthetic....

Since this thread is dead anyways and the Hopi never came back I will go ahead and hide jacket somewhere else. How many new coils have you had come in from eBay or Amazon or whatever that were not physically or obviously damaged in shipping. That were bad??
I'm really trying to get accurate numbers and be accurate about this because it frustrates me when people continue to repost information they have simply Read on a forum.
I'm on my somwhere between Sixth and eighth set and have not had a bad new one yet.
Took 8 years to have a misfire on the first set that I installed and that probably could have been cured with a new spark plug and a new rubber boot.
There are some cheap Chinese things on eBay that are junk and some that even I won't buy, again... I got burn twice on window regulator assemblies by doing two in one month. Neither one lasted 45 days so I will not try any more cheap ones. I will go with dorman with a lifetime warranty and my local parts store.
But I have had zero problems and nothing but pleasure and success and great super cheap low prices with coils.