Problems with a 2003 LS V8, need some help

Tom_Cat

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HI ALL!

I just picked up a 2003 Lincoln LS V8, I am having some problems with the car.

Here they are.

Engine

Running on 7 cylinders, mill on and flashing under power. I am hoping it is just a coil.

Fuel system, this is where things get weird.

I had to unplug the fuel presser sensor just to get the car home, with the sensor plugged in after about two miles it would lose power and become unresponsive no matter how hard you stepped on the gas. I unplugged the sensor and it ran fine, plenty of power.

It runs out of gas on ¼ tank! No low fuel light or anything, put gas in it, fired right up. Could this be a bad jet pump?

Transmission

Harsh 1 to 2 shift, all other shifts smooth.

Skips 3rd and goes to 4th gear and then drops back to third on light acceleration, goes through all the gears fine under power.

Trans dos not slip, engages reverse or drive just fine, no delay.



Thank you for your time!

Tom_Cat
 
...Running on 7 cylinders, mill on and flashing under power. I am hoping it is just a coil...

Odds are that it is a marginal or failed COP (coil). Spark plug(s) must be changed at the same time as COP(s). They must be set to 1.0mm gap (verify the pre-gap'd plugs). You should also check the the connector correctly latches into the COP, and do the same check for the #7 fuel injector connector. Another possibility is an air leak at the #7 runner. If it's a failed/failing coil, your are advised to replace all eight COPs now, and to use only Motorcraft.


...Fuel system, this is where things get weird.

I had to unplug the fuel presser sensor just to get the car home, with the sensor plugged in after about two miles it would lose power and become unresponsive no matter how hard you stepped on the gas. I unplugged the sensor and it ran fine, plenty of power...

You need to use a scan tool that can read all the real time data and DTCs available. Forscan is suggested as the lowest cost way to do this. Read the fuel pressure while comparing it to the reading of a mechanical fuel pressure gauge. It probably will be a bad FPS.

...It runs out of gas on ¼ tank! No low fuel light or anything, put gas in it, fired right up. Could this be a bad jet pump?...

It could be the jet pump, or it could be a bad or sticking fuel level sender (there are two of them). Monitor the fuel level sensors and see which one (if either) seems invalid. You could also remove the jet pump cover (driver's side) and see if there is still fuel in that sump when you run out. I'd watch the two fuel level sender values while using fuel first.


...Harsh 1 to 2 shift, all other shifts smooth.

Skips 3rd and goes to 4th gear and then drops back to third on light acceleration, goes through all the gears fine under power.

Trans dos not slip, engages reverse or drive just fine, no delay...

There are a few possibilities, maybe someone with your exact symptoms will chime in.
Guesses: worn servo bore, broken servo (probably not), valve body issue (broken spring, leaking gasket), solenoid assembly problem (probably not), PCM fault.
 
Likely a coil, which is the good news. The bad news is, it is also likely that you need a new PCM. Hard to come by and a lot of the time a junk yard one won't be good. I've had all of your issues before. Replace the coils with OEM and do the plugs (do them all now). Replace the fuel pressure sensor. Try to hunt down a PCM. There's a company in Florida that will refurbish PCMs. I don't remember the name of them off the top of my head, perhaps another member will chime in. I sent my PCM to them and they reprogrammed it perfectly. Solved all of my shifting issues.

Found it: Lincoln LS ECM / ECU Repair & Return - SIA Electronics
 
Last edited:
I think I got the running out of fuel problem fixed.

It was the jet pump; the filter (sock) disintegrated and got sucked into the pump completely plugging it!

I cleaned it out and it is down to 1/8 tank of gas and still running :)

Now the snow/rain hit so it will be a bit before I can work on it again.

Thank you for your help people!

Tom_Cat
 
Speaking of rain...
If you find signs of rust in any of the plug wells, you'll probably need to replace the gaskets/seals around the wiper shafts on the cowl.
 
Speaking of rain...
If you find signs of rust in any of the plug wells, you'll probably need to replace the gaskets/seals around the wiper shafts on the cowl.

Which seals are you talking about? I may need to replace mine... Are they at the bottom of the wiper arm?
 
Which seals are you talking about? I may need to replace mine... Are they at the bottom of the wiper arm?

More or less. The passenger side one is a foam gasket. You could use some weather stripping to do it, but it's only a few dollars from a dealer. The driver's side one is more complex and is some molded rubber. It seems to last longer though.
 
Ok, got the fuel presser sensor changed out so that problem is solved.

Now I just have to install now coils and plugs.

Dam nice car I like it!
 

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