mattbrunt

Howdy, folks!

I'm brand-spankin' new, here. I ran some searches for this topic so as not to waste anyone's time. If there is a thread in existence, already, please point me to it. I'm sure it's possible I just didn't word my search string clearly enough.

That being said, I've been having ignition problems with my 99 F150 XLT for a while, now. I have had some sequences of support on a couple of sites, so I would be happy to go into the details of this particular maintenance journey if someone is interested. In the meantime, I have one question that I can't seem to find a reliable answer to:

The friend I bought this truck from had the engine replaced in 2015 with an equivalent 4.6L V8 from a '99 Crown Vic. The truck ran great for 2.5 years. Last Fall/Winter, she blew out the first of a series of coil packs on the way to isolating the PCM as a likely source of the ignition problem. I bought a new PCM based on the label identifiers on the one I pulled. After swapping out the PCMs, still no ignition. Those PCM label identifiers are for an F150. Here are my quesions:

1. If the engine has been replaced with a Crown Vic engine, would the mechanic who did the job have had to reprogram the F150 PCM for the Crown Vic engine?
2. Should I have been shopping for a Crown Vic PCM?
3. I've been told to not shop for PCM based on specs, but only based on the identifiers on that label. Is this true? If so, how do I find the appropriate PCM?

Any other info you guys would like to know, please feel free to ask.

Thank you in advance!
Matt

formerjeepguy

Is this a new PCM or a junkyard pull? Was it programmed specifically for your vehicle - They need to take your VIN number and program the PCM for your vehicle as built and then apply any updates so it is a perfect match for your truck.

The PCM is vehicle specific and not engine specific. If you replaced the PCM then it needs to be synced with the rest of the modules. You can do this with forscan software and an elm327 obd2 adapter. You may also need to reinitialize the PATS system.

I went through a PCM replacement on my truck back in January.

BareBonesXL

Jbrew

First of a series of coil pacs ? That engine has only 2 coil pacs along with plug wires correct ? Verify/solidify that real quick, -since ignition systems changed the following year for the 4six. The way it's described in your post are problems one might see with COP ignition systems (no plug wires).

Plug wires or No plug wires ? That's the question.

Jbrew

Well, apparently it's a tough question for you. You must know someone that can verify whether or not that engine has plug wires. Have them assist you if warranted or confused. This way your questions can be addressed correctly, problem easily confirmed.

mattbrunt

Thanks for the replies, fellas!

Admittedly, I'm no mechanic. However, I can be handy when forced to be. I've done my homework on this, so far. That's not to say I haven't missed something here or there, but I've been thorough.

1. This question about plugs is not a hard question. The rig has plug wires. No COP, 2 4-banger coil packs. Waste-spark system.
2. By "series of coil packs", what I meant was that I was blowing and replacing them. I've now replaced the driver-side coil pack 3 times since last November. The first replacement was my doing. The next two were at the strong suggestion of certified mechanics who were certain they'd found and corrected the problem.
3. The PCM was ordered new, pre-programmed from Flagship One. I used the VIN to order and verified that the part #s matched.
   • Incidentally, I recognize that PCMs are vehicle-specific. This is actually the source of my question. The vehicle identified by my VIN, and the PCM that shipped with it, are both identified with a certain engine, right? What I mean is that this truck shipped originally with a particular engine, and a PCM tuned specifically to that particular engine. The question I'm wrestling with is whether or not you can just drop any old engine in a Ford F150 and still buy a Ford F150 PCM and expect it to work. I mean, the PCM is controlling everything: ignition timing, idle speed, emissions, fuel delivery... All of that specific to a particular engine within a vehicle with a particular VIN. Am I right? I'm not being snarky, I swear. Just asking.

Jbrew

When you order from Flagship One they usually will need the number off the old PCM to confirm calibration, but they can do it thru vin # as well....I don't see why not. It's a good company, they've done right by me.

The 4six engine from the CV will work, it's the same engine as the truck below the intake. In order for it to work in the truck, you have to use the trucks intake. As long as the intakes were swapped, the PCM will run engine just fine. You would also need to use the trucks engine harness, not the CV's. Everything electrical needs to be truck. In other words, all you want from the CV would be the engine below the intake period. So as long as the swap was done correctly, there shouldn't be any problems from it.

Burning up coil packs like that is unusual. Hard to say what's causing that , specially if you didn't do the swap.

formerjeepguy

Regardless of engine compatibility issues, it isn't going to start until you pair the PCM with the other modules.

I used flagship one too and my PCM works great, but only after pairing it with the other modules.

Jbrew

Try it this way, might help lol.

1. Absolutely not. - Same engine, same sensors, same communication from below the manifold. Everything is the same as long as the swap was performed correctly. If not, -Good Luck lol.
2. Hell no. ALWAYS use the factory original PCM and just as importantly, wiring harness. Ford changed routing, circuitry and fuse blocks often...half year models can even be different. Crown Vic totally different in this regard.
3. From 97-98 PCM's from Flagship One are plug and play. From 99 plus, you need key programing after receiving the PCM. This is due to the PATS addition from 99-03/04. A visit to dealer is needed. If your lucky, some locksmiths can program a key for yuh. All you need before ordering the PCM is the numbers/letters/identifiers, call them what you want are the calibration. There's also a calibration sticker in the door jam. It's about half way up above or below the door latch post. IF it's still there. Flag ship programs with the latest updates for your model. But yea, 99 plus needs a programmed key.

Actually, I think there is way to get past the key programming. It was posted on UTube by FordTechMakuloco. Vaguely recall, it might be worth looking into.

01-7700

The part in bold would have me doubting much of what was said in replies. How do you account for that?