Interesting idling when weather is >65 degrees/interchangeable ECU's?

[Manlavi95]

Title gives it away. Any time the outside temp is less than 65°F, if I let the truck idle after a cold start, after about a minute or two, the RPMs will drop dramatically and it'll start sounding like it's cammed. I look at the sticky, none of those seem to be my problem, but I'll triple check tomorrow. Don't get me wrong, it sounds awesome, but I know it's a problem. Which brings me to a second question, what ECU's are interchangeable with the 2000 Expedition 5.4? I'm assuming any other 5.4 Half-ton above 1999 and before 2004, including F-150's. I'm asking because I know there must be something wrong with my ECU, because I contacted PHP and we narrowed the reason for my programmer not being able to program to a bad PCM. Both communication wires work, and I know the 18v wire works because I actually volt tested it at both the OBD-II port and PCM bulkhead connector. Gonna go to a parts yard and find another PCM. I appreciate anyone taking the time to read all of this, and here is a video showing my idle.

Interesting idling problem in the cold - YouTube

 

[Bowesmobile]

Okay, so I think you're on track. The cold idle seems a little high. But get a new PCM from a similar year and try it out. Watch out for the security and make sure the key will work. But I dont know what else to warn you about. You seem on track.

 

[Manlavi95]

Okay, so I think you're on track. The cold idle seems a little high. But get a new PCM from a similar year and try it out. Watch out for the security and make sure the key will work. But I dont know what else to warn you about. You seem on track.

Thanks for the reply, I've been hearing about this security stuff lately, what exactly should I do and not do? I thought it would be as simple as swapping PCM's

 

[Manlavi95]

Hmmm.

 

[FordandPolaris]

Colder weather will bring out ignition issues. I can't watch the video yet but the computer in my truck has seen -20 temps and keeps the idle ok, spark plugs and COP's on the other hand didn't take the weather well.

Im not saying the programmer guy is necessarily wrong, but if your motor is not running like a piston fell out, and is idling ok at some temps and not others, it seems much more likely to be ignition/sensor related.

 

[Manlavi95]

Colder weather will bring out ignition issues. I can't watch the video yet but the computer in my truck has seen -20 temps and keeps the idle ok, spark plugs and COP's on the other hand didn't take the weather well.

Im not saying the programmer guy is necessarily wrong, but if your motor is not running like a piston fell out, and is idling ok at some temps and not others, it seems much more likely to be ignition/sensor related.

I wonder when the plugs were changed last. Scares me. Still have to try a new ECU, know which one's are interchangeable? Should be bolt-in/plug-n-play right?

 

[jdecker]

Have you checked to see if you have any pending codes? It is acting like it's trying to compensate for a fuel mixture problem. Just guessing I would think it might be a leaking intake gasket.
Also the pcm will not be plug and play, it will have to be flashed to your particular truck and the pats(security) will also have to be programmed for your keys.

 

[FordandPolaris]

I got a chance to watch the video now. That is definitely interesting. Have you checked the idle air control valve? Your engine is idling high, even when not missing

 

[american steel]

your ECU PCM or computer is one thing that will not cause winter issues it happens but that is extremely rare on these vehicles.
sounds like you're having misreading issues one or some of your sensors need to be replaced and or cleaned out. check with your MAF sensor. that cause's a lot of weather issues, it sends signals to the ECU if its of the computer will try compensate for the weather barometric pressure temps and all that stuff.
more than likely its a sensor problem.
don't change your ECU don't even think about it!
spark plugs work better in cold weather so do injectors.
also check all of your hoses they might be rotted in a place you cant see.

 

[Manlavi95]

your ECU PCM or computer is one thing that will not cause winter issues it happens but that is extremely rare on these vehicles.
sounds like you're having misreading issues one or some of your sensors need to be replaced and or cleaned out. check with your MAF sensor. that cause's a lot of weather issues, it sends signals to the ECU if its of the computer will try compensate for the weather barometric pressure temps and all that stuff.
more than likely its a sensor problem.
don't change your ECU don't even think about it!
spark plugs work better in cold weather so do injectors.
also check all of your hoses they might be rotted in a place you cant see.

It's not just the idling that I'm worried about when it comes to the PCM. It's because I bought an Edge Evolution CTS, and there are three wires that communicate with the PCM. Two work because those are the ones that send info to the gauges on the screen of the tuner. I tested the third and it's getting the 18 volts that it should. So the only next option is to replace the PCM, because I can't figure out what else it could be. I'll clean the MAF. What should my idle be at?

 

[american steel]

idle on these engines should be 600RPM.
with these older engines buying these stupid little tuners are a waste of time and money especially when the 5.4 and 4.6l aren't that great at producing power or torque by todays standards.
if you want more power you'll just have to do a small head port job a little bigger cam grind not the duration just extra lift and headers also a bigger throttle body.
I've seen so many bad motors because of tuners. piss poor timing valves kiss the pistons etc etc. its a waste.
there is no need to change ECUs if a tuner is giving you issues because of wires then you need not use it. tuners don't give much for these older motors.

 

[Manlavi95]

idle on these engines should be 600RPM.
with these older engines buying these stupid little tuners are a waste of time and money especially when the 5.4 and 4.6l aren't that great at producing power or torque by todays standards.
if you want more power you'll just have to do a small head port job a little bigger cam grind not the duration just extra lift and headers also a bigger throttle body.
I've seen so many bad motors because of tuners. piss poor timing valves kiss the pistons etc etc. its a waste.
there is no need to change ECUs if a tuner is giving you issues because of wires then you need not use it. tuners don't give much for these older motors.

I was going to actually start doing fast parts sometime next year so I thought a tuner would be a wise decision when it came to tuning, maybe I was wrong. Guess I'll have to buy some good old real gauges when I get into the turbo project.

 

[american steel]

I was going to actually start doing fast parts sometime next year so I thought a tuner would be a wise decision when it came to tuning, maybe I was wrong. Guess I'll have to buy some good old real gauges when I get into the turbo project.

yeah stay away from a tuner unless your vehicle is a few years old a tuner isn't going to help with power out put.
if you're going turbo or supercharger in the future you have to a full rebuild.
factory crank is fine and can handle 800HP.
you're going to have to buy forged rods and pistons.
ported heads will make forced induction that much better especially when factory NPI or PI heads are very restrictive if you have a NPI motor I suggest you buy a set of PI heads they are dirt cheap.
if you won't to invest in new cams but don't change the intake and exhaust duration just the lift.
the computer will need to be tuned by a performance tuner to make up for the extra air fuel ratios and such also you'll need bigger injectors this is something you need to talk to a ford EFI performance guy about.
your trans will have to be rebuilt.
if you don't plan on F/I all you need to do is upgrade your H/C/I and shorty headers, TB
basic bolt ons are cheap for these motors.

 

[Manlavi95]

yeah stay away from a tuner unless your vehicle is a few years old a tuner isn't going to help with power out put.
if you're going turbo or supercharger in the future you have to a full rebuild.
factory crank is fine and can handle 800HP.
you're going to have to buy forged rods and pistons.
ported heads will make forced induction that much better especially when factory NPI or PI heads are very restrictive if you have a NPI motor I suggest you buy a set of PI heads they are dirt cheap.
if you won't to invest in new cams but don't change the intake and exhaust duration just the lift.
the computer will need to be tuned by a performance tuner to make up for the extra air fuel ratios and such also you'll need bigger injectors this is something you need to talk to a ford EFI performance guy about.
your trans will have to be rebuilt.
if you don't plan on F/I all you need to do is upgrade your H/C/I and shorty headers, TB
basic bolt ons are cheap for these motors.

I believe I have the PI's because it's a 2000, I'm definitely going to get cams, definitely going to go talk to Panhandle Performance about the tuning, I'm going to ZF-6 swap it. What is this I hear about a bigger throttle body?

 

[american steel]

I believe I have the PI's because it's a 2000, I'm definitely going to get cams, definitely going to go talk to Panhandle Performance about the tuning, I'm going to ZF-6 swap it. What is this I hear about a bigger throttle body?

bigger throttle body = more air and if you want cams and or forced inductions you're going to need a bigger one.
good luck with that trans swap.
not all 2000s had PI heads.