2003 Lincoln LS throttle body codes, need help please

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dogsled

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I have a 2003 Lincoln LS, V6, 110K miles, 2nd owner. It was my wifes car, she bought it with about 30K miles. About 15K miles ago it started throwing codes for misfires and coils and went into fail safe mode. So I did some research, saw all of the issues with the coils and valve cover gaskets. I replaced all 6 coils (from RockAuto, not sure of the brand) the valve cover gaskets (felpro) and plugs (bosch platinum) at that time. There was an oil leak on the passenger side. Not long after that, it threw another coil code (thankfully for the driver side so easy to replace), so I took one of the old ones and replaced the one that was throwing the code (I have my own scanner) and all was well until recently. Now it has started going into fail safe mode and throwing codes for the throttle body stuck open, throttle body stuck closed, throttle position sensor and throttle body mod actuator, and low fuel pressure. I have misplaced the paper that had all of the numeric codes, but that is a summary of the issues. Given that the majority of the codes were throttle body related, I picked up a throttle body from a salvage yard from a 2011 Crown Vic with 30K miles. Put that on and still codes and going into failsafe mode. Now I only get the throttle body actuator code when it goes into fail safe mode. I have noticed that it misses when rev'd up to about 3000 rpm sitting in the drive way with it in park (not sure if it did that with the old throttle body or not). It is not throwing any codes for coils or misfires and the misfire counts for all cylinders are zero according to the scanner. I have read that it could be coils causing the erroneous throttle body messages, so I'm wondering if that is it given the miss. Here are the questions that I was hoping someone could help me with as I am at my wits end with this car.

Is there an electronic or printed version of a shop manual available for the LS? I have seen a few diagrams online that look like they came from a manual, but no source for a manual.

Can the coils be tested? Is so how? I have checked the resistance on the two pins and all of the coils that I have seem to be about the same, new and old.

That low fuel pressure code has me wondering if this could possibly be caused by a fuel pump failing or clogged fuel filter?
I have not ohm'd out the harness or checked any of the voltages at the throttle body, but my scanner will record data about throttle commands and position and is does change when recording data and pressing the pedal.

Is there a procedure for stress testing the coils? I have access to an oscilloscope and multimeters and my actron scanner.

The miss only occurs at about 3K rpm, it idles fine. Seems to throw the codes when under hard acceleration. Any procedures or tips on how to check any of the above issues or other relevant topics would be appreciated.
 
I didn't know the CV went to electronic throttle control........ I would still suspect the coils; specifically #3 (passenger side, nearest the firewall). That seems to be the location that causes the most problems.

I got a service CD off of eBay for cheap.

There is a 3K rev limiter in "P" & "N". You're bouncing off the limiter when you hit 3K RPM.
 
LS4me said:
I got a service CD off of eBay for cheap.

There is a 3K rev limiter in "P" & "N". You're bouncing off the limiter when you hit 3K RPM.
Click to expand...

Roger, I'll check Ebay for the manual. So the "miss" is really the rev limiter kicking in, not a miss exactly?
 
dogsled said:
Roger, I'll check Ebay for the manual. So the "miss" is really the rev limiter kicking in, not a miss exactly?
Click to expand...

If you're "flooring it" in park or neutral once you hit ~3K RPM the computer cuts off the fuel, which feels like a miss.
 
LS4me said:
If you're "flooring it" in park or neutral once you hit ~3K RPM the computer cuts off the fuel, which feels like a miss.
Click to expand...

makes sense, thanks. Do you know if the PCM needs to be reset after the throttle body swap? I read in one post that it did. I have not yet done that. I doubt that will fix the issue, but it is easy enough to try.
 
Does the Crown Vic use the same throttle body? And, does it use the same TPS? You can compare throttle body and TPS part numbers on Rock Auto to see if they are the same. A salvage yard TPS may also be introducing its own problems to the mix as you don't know what weather conditions it was in before you bought it. Water may have gotten into the sensor, which will corrode the inside of the TPS. Used electronics are rarely worth the money.

It's never wrong to change the fuel filter either. But, for some dumb reason Lincoln decided that behind the driver side wheel well was a good place for a filter. You actually have to remove the driver side wheel from the car to get at it, and the only thing between the fuel filter, the plastic fuel line and a piece of steel road debris caught by the driver's front tire is a 1/8 inch piece of plastic. :mad:

So far as Bosch plugs, I agree, don't use them anymore. Bosch used to make pretty good stuff, but they've moved a lot of their manufacturing to China and the stuff isn't worth buying anymore. NGK makes a good plug, as do AC and Motorcraft.
 
Telco said:
Does the Crown Vic use the same throttle body? And, does it use the same TPS? You can compare throttle body and TPS part numbers on Rock Auto to see if they are the same.
Click to expand...

According to Rock Auto the sensors are different:

STANDARD MOTOR PRODUCTS Part # TH440
STANDARD MOTOR PRODUCTS Part # TH381

According to 1aauto.com, ebay and the salvage year where I bought the Crown Vic throttle body, the part number for the entire assembly is the same for the 2011 CV and my 2003 LS.

I am a bit confused by the apparent disagreement.
 
dogsled said:
According to Rock Auto the sensors are different:

STANDARD MOTOR PRODUCTS Part # TH440
STANDARD MOTOR PRODUCTS Part # TH381

According to 1aauto.com, ebay and the salvage year where I bought the Crown Vic throttle body, the part number for the entire assembly is the same for the 2011 CV and my 2003 LS.

I am a bit confused by the apparent disagreement.
Click to expand...

I wouldn't trust a salvage yard or eBay; and 1aauto shows different stock numbers on their site (I used 2006 for the LS which uses the same TB as the 2003). Trust Rock Auto, or even call your dealer and see what they show. I would be very surprised if the TBs are interchangeable.
 
LS4me said:
I wouldn't trust a salvage yard or eBay; and 1aauto shows different stock numbers on their site (I used 2006 for the LS which uses the same TB as the 2003). Trust Rock Auto, or even call your dealer and see what they show. I would be very surprised if the TBs are interchangeable.
Click to expand...

The V8 and V6 use the same throttle body? (I show different part numbers, but it isn't clear.)
 
And there's the problem. I would return the TB to the salvage yard, tell them you found that it is incompatible after all if they told you it would fit, then go buy a new correct TPS for your old TB. It's rare that the TB itself will fail, but TP sensors are a variable resistor that uses a wipe arm on a wire coil to show position; this is a wear item and should be replaced regularly, like when you get a TPS sensor code on the computer.

If you bought it on your own with no input from the yard, you're probably stuck with it, which isn't a bad thing. Since it bolted to the intake, it's a fair bet that the correct TPS will bolt to the TB. So long as the throat of the TB is the same as the LS TP, or within a few mms, it will work fine and the computer will compensate. If it's more than, say, 5MM different then you might have problems that a tune would correct.

On the replacement TPS, get a Motorcraft version, not the store brand. Store brands are made to fit as many different cars as possible, and the specs are set wide enough to kinda work on all the cars possible. The Motorcraft one will be an exact fit and will work correctly.
 
replaced the junkyard one with a new TB from Rock auto, still throwing TPS codes. Will look at replacing coils again, I guess.
 
Did the coil and plug swap myself...and didn't use motorcraft plugs...needless to say that after about 2 months I started getting misfiring again...did the job again with oem plugs and the engine runs great...If you are changing plugs, use motorcraft, or you will probably have to do the job again.
 
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