So I’m wondering ?? the stock 4.6L in my 2005 Ford F150 has only 50K miles on it. This one is a complete dog, it has no throttle response, no low end torque at all.If it were an old school engine I would say the timing is very retarded. Which I could just replace the vacuum advance, and advance a distributor and call it a day,But unfortunately it is not that easy. I have no CEL lit, it shows no codes on a scanner, I don’t think the cat is clogged because it will rev out(slowly), and it get no foul smell . I have driven several of these trucks with the small V8, and also my dad’s big Mercury had this same engine with LESS gearing, and would run circles around this truck.I had a 2000 with V6 that was peppier, so that’s pretty poor ?Any ideas,? Other than the basic, “ did you check the air filter? thanks, Crossy

 

I would think about android phone /5$ torque pro app /amazon bluetooth reader . Look at test results raw data per cly short of setting cel . Plus fuel trims and much more . Ford set threshold to on cel quite high . This will give you access to raw counts .It also gives you the min to set cel . At 50k for a 05 is quite low and should be trouble free . Maybe gunked up injectors you tube diy cleaning set up. Is this orig engine , my 05 at 196k .
Ford now says change plugs at 60k and boots .
I would not expect a timing problem . Clean throttle body off truck .Injectors seat with new motor oil . I'm not that familiar with 4.6 . It does sound like a good check of cats are called for the torque will give you temps and o2 volts and readings in and out of cat .
You can screen shot torque screen and put it on here . We have some good diag people . I'm sure you looked at your fpdm for corrosion on rear axle which is a real common problem with fuel .Usually it shuts you down but when water getting into it it can be very intermittent and weird . If it isn't bad it will be going bad . New ones are on standoffs. .

 

I will do the throttle body for sure, and look at the FPDM. Since they are cheap now I may even throw one on just to know it's done. I bought the truck because price was never a consideration to the previous owner, he's just that way.
but you MENTION a timing problem? I just assumed there was no real timing, and everything like that is done through it's PCM? thanks, Crossy

 

Your conclusion on the cat converters is not based on evidence. Even if they are good, there still could be a blockage somewhere else in the exhaust system. It sounds more like clogged exhaust than anything else to me.

 

All engines have timing . This one is set by chain alignment to cams and crank . Yes it can jump time not likely at this point . You don't have phasers but you do have chain tensioners . No sense going there but exhaust problems most likely at this point . Learn to check cats fuel/ oil and misfires can damage cats .
Pcm must know where crank is at by tone ring on crank and crank sensor tells it that .It must know where cams are at ,cam sensor tells it that . But this is a interference engine meaning that if cams push valve down at wrong time they get bent . Chain locks them together with certain timing marks on crank/cam gear and colored links on chain . No reason for you to go there now . But you may have a different engine that came on it if reman done.
Pcm changes advance and retard spark. injector pulse and width but it uses many factors besides cam sensor /crank sensor .It can't change base time . 5.4 l are much more complicated and adjust cams constantly off idle It does it with vct solenoids hydraulically with dirty engine oil, forcing cam phasors to move ,vcts are controlled by pcm signals .
If original change fuel filter under drivers side .
Any chance this engine redone by other owner ,was it running good for you at all .

 

Have you pulled a spark plug? The low mileage indicates lots of idle and short trip driving. Its not uncommon for the spark plug gap to get near .065 and cause a big with no misfire.

 

Sounds like a normal 4.6 to me. Every one I have driven was a dog, you have to wind them out to 4-5K to get any power from them.

 

AND like I said, I have driven many, but never one as 'doggy' as this one, and yet it runs,idle,drives great, But I wouldn't tow an aluminum dingy with this one, MAYBE a blow-up raft in the bed .lol

 

It might have higher axle gears than what you are used to.