I officially give up

[Diplomat 1]

Well as some of you guys might know I have idle roughness on my 03 Lincoln ls. It looks like the 5v ref signal is not going to the maf. It's not throwing any mad codes. I resent it out to Sia they say nothin is wrong with the maf circuitry. I am completely baffled. I have changed the sensor, connector and ran a new wire from the pcm to the maf and still no difference. I am really outta words right now just very pissed off. I know this is the problem and I can't figure how to fix this pos. Gonna drive it off a cliff smfh

 

[LS4me]

What gas? Injectors ever cleaned?

 

[Andrizzle]

I remember all your threads about this. I feel like you got coils out of the same batch as I did from last year.

 

[Zach2211]

Did you replace your intake gaskets and check for air leaks (cracked boot or hose) around the MAF? Those accordion boots like to get little hairline cracks between the ribs.

 

[joegr]

You've already run a new wire, so your harness is already a little cut up. A little more shouldn't hurt. Why not do some systematic trouble shooting and figure this out?
SIA said the the PCM was good, so let's verify that first. Disconnect (cut) the wire from the 5V reference in question from the PCM. Turn the key on.
Do your measure 5V coming out of the PCM? If not, SIA was wrong or your harness connector to the PCM is bad (it does happen).
If you do measure 5V, then reconnect the harness and measure again at the same spot.
Is there still 5V there? Yes - then you have a break somewhere in the wire(s). Find it and you're done.
No - then something is shorting out the reference signal. Disconnect all the loads and measure again.
Is the 5V back? Yes - one of the loads is shorted. Reconnect one by one till the 5V goes away. Now you know which sensor is shorted and needs to be replaced.
No - the short is somewhere in the harness. Keep cutting branches off of that signal in the harness till you find it.

There is no magic here. There's no way this can't be found.

 

[smithy27]

Have you fixed the issue?