Alrighty, well I got my truck back today after having the PCM replaced with a used PCM out of another '03 truck. I had to drive it around stock today because the strategy changed and I had to have my tunes rewritten. This thing was SUPER sluggish and felt like it had zero power. I could put the pedal on the floor and it didn't feel like it was accelerating any faster than if I just barely pressed the throttle past cruising point. Also, I noticed there was no turbo whistle (and we all know how freaking loud the '03 turbos whistle). It was building boost, very little though, but and you could hear it putting out air, so the turbo was working but it just wasn't near as loud as before. At first I thought maybe I had just gotten so use to a tuned truck that this was normal. I got my street tune on there just now and drove it around and it's nowhere near the same. The turbo STILL doesn't whistle, you can just faintly hear it blowing out of the tail pipe, and the exhaust does that super high pitch crackle/popping sound when I do WOT. Before the PCM went out, I could get like 30 pounds of boost at WOT...now I'm only getting around 20 pounds, maybe a little more. If the PCM is replaced (even if the PCM is used) does it have to relearn EVERYTHING like the turbo and all? Will this stuff eventually shape up or should I have it checked out. The engine also makes a more noticeable rumble sound while doing normal driving, like taking off from redlights. The only time I remember my truck making that same sound is when my turbo locked up once and my engine was running turboless. And when I got my truck back from the shop, at WOT it had about the same power that it had when it was turboless. Does this make sense to anybody? Should I have it reflashed to the latest strategy from Ford? The only problem that I could think of was that the guy at the shop said that the PCM isn't going to read the same VIN as the truck because it's from another truck, but would that affect the way it runs? I'm just getting very frustrated.

 

A lot of people looking at this thread...nobody have a clue?

 

any codes?
seems like your back to sqaure one... right before it died on you.
the shop that did it gave it back to you that way? or did this happen after words?

 

No there's no codes at all. I think the PCM solved my previous issues, because I've noticed several things better about this PCM. For one, the truck starts way faster than before and the engine doesn't turn over for near as long. Several of my friends with 6.0s had commented to me before about how long my truck takes to start, but I never thought anything about it because it's been like that since I can remember. But I can tell the world of difference now. These seems like a completely different set of issues. Do you think it could have something to do with the PCM still being "programmed" to another truck? I talked to the guy at the Ford dealership and he said they could run my VIN and flash it back to how my original PCM was programmed. Could this possibly solve the issue?

 

it may. Still need to go back and revisit the ebp,map, baro oressure values. being you have an 03 i would also look at the turbo learn pids and see if it has done it.

 

Ok, I'll check that stuff tomorrow. How could I check the turbo learn pids? I've never heard of that.

But as far as why he didn't catch it at the shop, I think it's because he was just driving it around normally on a flat road. It builds enough boost to drive it around normally, it's just when you try and get on the throttle or climb a decent hill that you have to really get into it just to maintain or slightly increase speed.

 

Cheezit, my insight doesn't do map pressure anymore. It use to... It doesn't do ebp either. But as far as barometric pressure goes, it stays at 14.2 no matter what the throttle position is. Should that number be changing?

 

Another thing I've noticed is that when I use to start my truck, there was a low pitch rumble from the exhaust, then once the turbo kicked in within a few seconds it went away and you only heard the air being put out at the tailpipe, and you could hear all of that from the driver seat. Now the rumble does not go away, and I have to walk towards the back of the truck before I can tell the turbo is putting air out at the tailpipe. This is also the case while driving...use to when I got on the gas just enough to pass someone, you would first hear that super loud 03 whistle, followed by a low rumble as the rpms went up. Now there is only a faint whistle with some obnoxiously loud exhaust popping. Don't know if that helps any.

 

baro is allways baro. its atmosphric pressure. that all it is. its what the pcm uses to know if the other 2 are worng.

 

Does a turbo go through a relearn process when a PCM is reset or totally replaced kinda like the torqshift does?

 

yes to both. But with no egr valve it may not work because part of the relarn process involves backpressure. however the turbo relearn issue will not set ebp,map, baro type codes.

 

I have a valve...and it's plugged in. As a matter of fact I plugged it in this morning and every time I've driven it today I've noticed the whistle getting louder and louder.