Okay, so I have tried just about everything to get this cursed truck to run good. Plugs, coils, phasers, phaser solenoids, chain tensioners, guides, lifters, catalytic converters, fuel filter, cleaned throttle body, MAF sensor, cleaned fuel injectors.

Truck has rough idle, has NO ***** (power), seems to burn a lot of gas, and has a little tick at idle when warm. And no CEL.

I’ve decided to replace the PCM before I tear deeper into this motor, and I’m trying to find out what all is involved. I’ve looked at the ones at the local part stores, and they all say they will need a computer flash (I think the ones from Autozone come pre-flashed). Also, there are like 10 to 20 different “module numbers” listed for my truck and engine, and I cannot find anything resembling them on my PCM. So, looks like no matter what, I’m going to have to take it to the stealership to get it flashed (If I can even find the right “module number”). I was thinking about getting a used one from Ebay (with the same part number of course), then having it flashed to my truck (At least I could match the part number).
I will replace this engine if I have to, but wanted to try a different PCM first and just want to know what involved.

Thanks!
Jeff

 

Hey.

Ye dint mention O2's (specificalyl the front pair) ....
Have the drivers for the plugs and injectors been tested?
Wiring/harness inspected?
What aboot a full IDS diagnostic and'or a live data diag (while driving) and review?
Many inputs like cam & crank position sensors, knock sensors, CMCV system, etc.
Fuel pressure checked?
FPDM inspected?
NO stored/pending codes? Mode 6 data shows no issues?
Out there - plugs, etc have been known to be DOA out-of-the-box.
Healthy electrical system - full voltage, good grounds?
Borescope inpsection of the cylinders?

Seen? https://www.f150online.com/forums/v8...-problems.html

https://www.f150online.com/forums/20...once-warm.html


It still may not be the PCM, is my point. It's usually not the issue - especially if the truck runs.

As fer the PCM, yer least-hassle avenue is the Dealership, overall. Will cost more, but used PCM's can be a crapshoot, and you still need the correct flash (PATS involved?).

Throwing parts at it is expensive and frustrating - and so far fer you, fruitless. You need a plan, comprehensive diagnostic data, and should change only one thing at a time, then assess after each action.

good luck
MGD

 

The front O2’s were replaced awhile back. Would be worth looking at again I guess (I think I have some spares laying around), although I think they are okay because the truck starts up rough before it even gets to closed loop.

Not sure how to test the coil and injector drivers. I’m guessing with a meter or test light? Will check the wiring again, but I would think, if it was wiring, it would be intermittent.

I have not let a dealership run a diagnostics on it yet, but I do have SCT software to view data. I just don’t know what I’m looking at. I haven’t check the CMCV system yet, I will definitely check into that!

Fuel pressure seems good. I have not hooked up an external gauge, I just read off of what the PCM reads, and it seemed good (steady at 39psi I believe). I just did a visual inspection of the FPDM, and it looked good.

There are some codes, but just ones for my rear O2’s being disconnected. What is Mode 6? Will check voltage and grounds. Can I rent a borescope? I did do a compression check. All checked good.

You are right, I do need a plan. Throwing more parts at it will probably only frustrate me further, and I want this thing fixed! I will check some things you mentioned, and if I can’t get it, I will just take it to the dealership and have them do a diagnostics.

Thanks for your reply!
Jeff

 

Fix that before you even think of taking it to a dealer. They will just tell you it has to be fixed before they can complete a proper diagnosis. If you fix it, clear the codes, and any codes come back, fix it or your diagnosis money will be wasted.

 

Thanks, will do that!

 

Okay, here’s a little update. I have fixed my rear O2s, cleared the codes and none returned. So I finally took the truck to the dealer and had them run a diagnostics with the IDS and they came back with nothing. I kinda got the feeling that they didn’t really want to mess with it so much but anyway.

I decided to tear into the motor again because I’m still betting the problem is oil pressure related / the VCT system. I tore it down all the way to the block this time. I dropped the oil pan and checked the crankshaft end play, which was good at right under .010” which is good correct? I was going to pull one of the bearing caps off but since the motor and oil pan were so clean I didn’t mess with it. I pulled the heads off to look at the cylinders and valves and didn’t see any problems. I kinda kick myself in the butt for it though because I forgot to remove the tensioners before I took the heads off and once I removed them I found a bad tensioner seal on the left side. I just replaced both tensioners like two years ago. They were the Cloyes ones from Rockauto. So now I feel like I’ve had a defective seal causing my problems all this time. Who makes good solid tensioners for these engines?

Anyway, everything else looked fine internally. I will be putting on new OEM phasers because I had the Dorman ones before and I have heard that they can cause problems. I will also be installing a new oil pump. Is there anything else I should check while I have this thing tore apart?

I will post some pics soon.

 

 

 

From all my research and experience with 3V 5.4 the factory tensioners were updated later and are as good as the they get but TFS makes some high quality valve train stuff you may want to check out. My 04 went 420000 kms before I totalled it. It is quite common for the variable cam motors to tick a little.

 

See what Tasca wants for the latest OEM tensioners.

 

Okay, Tasca has two different ones listed that will fit my engine. One just looks beefier than the other to me. Which one should I use? And I'm guessing they come individually and not in a pair? Thanks


http://www.tascaparts.com/ford/f-150...name=tensioner


http://www.tascaparts.com/ford/f-150...name=tensioner

 

Send a PM to the Tasca rep here with your VIN, he should be able to tell you.

 

Will do. Thanks

 

Is there a procedure I need to do to prime my new oil pump?

 

Okay now I've scratched my head on the mating surface where the gasket lays while trying to put the damn thing on. Is there anything I can use to fill in the scratch? I feel like this may lead to a leak later and I don't want to chance it.