I am trying to sort out my low milage XKR,
Shop replaced supercharger bypass valve actuator, diaphragm was shot. And replaced fuel pressure sensor.
Driving the car which runs fantastic, to accumulate the needed values for a smog test.
While driving i will get periotic CEL, shows a stored P0193 code.
Returned to mechanic to resolve, he physically tested fuel pressure of 55psi at idle, and states value should be 45psi.
Advises replacement of fuel pump/pressure regulator assembly, $3600.
I have read that this car has a fuel pump control module, could this effect pump operation? And where is it located?

By the way the bypass valve actuator that was replaced was used, as this part is no longer available , I kept the old one if it can be rebuilt.

Thanks in advance for any comments!

 

I believe 55 psi for the fuel pump is correct....

Do not cough up the additional $3,600 to that mechanic. You have not done sufficient diagnostics at this point....

 

Replace your fuel filter before you do anything else. It is a very inexpensive part and it can affect the fuel pressure.
My car is a 2002 XKR and it looked like it had the original fuel filter when I bought the car last year.
Needless to say, they should be changed more often and mine was causing problems.
Alan.

 

+1 on 55psi being correct.

Here's the DTC list entry for the P0193 code:

 

As someone who has been living with an occasional p0193 for years I wouldnt worry about it too much (unless it is effecting fuel delivery and trims) and I DEFINITELY would not give someone 3,600$. Actually I would punch them in the jaw just because.

The code is usually and occasionally triggered in that second before you even start the car when the pump kicks in to prime the system. It taps it just above the threshold for a sec and then the car starts and BAM, p0193. After a drive or 2 it will disappear.. Mine usually plays up when I cycle the key and start the car a few times in a row for whatever reason. In the keying intervals the pressure will still be high from the LAST priming, and then when I key the car over again that 2 second blast pushes the code over.

I do this all the time when typing on my phone and need to go back and check the OPost. Did you say you recently replaced your pump assembly? Was it for the PR Valve?

If so, I hope you kept the old assembly. If the mechanic has GO GET IT BACK! If the old pressure relief was good put it into the new assembly. Even if you thought or were told that the old pressure relief valve was bad get the assembly back, check it and make sure that what was making the PR valve bad wasn't worn orings (there are 2) in the underside of the PRValve.

For all of us. Finding the specs and replacement numbers for the pressure relief valve is a thing. We need someone to REALLY go on the hunt for it.

 

@Brianh what is a/the "bypass actuator"? Is it what's in the photo below?

I did it again, lol... Now I have to go back and get the exact language you used in your OP...

EDIT... I would NOT guess that it's the FPControl module... If you have a 4.2SC car with the return-less system the fuel pressure/pump control module is in the trunk, right over the back right hand corner of the battery about 10inchs up to right and back. Silver. You have to remove the carpeting that covers the cd changer and nav system, and maybe the carpet that covers the gas tank. Will have 2 skinny white control wires (from ecu), a black brown and yellow/red wire in the plug in to. Held in with 2 bolts... You can git them on eBay for 40$ because they never fail.

If you can, and if it is what's in the photo (this is what makes my p0193 happen), if the bypass actuator you describe is the PR valve found a the top of the fuel pump assembly, please ask the mechanic about any information he can pass on about the specs of the actuator.

Is your car a 4.2iter, or 4.0?

 

If I were you I would monitor the IP sensor live data as I was driving and see if it looks correct before doing anything else. From the fault code it looks like you would get a pretty dramatic spike in the values if it is going wrong occasionally, triggering the code. With something like the Torque app you can record the data and review it later, or plot it as a chart.

If you need to start taking the fuel pump etc apart JayJagJay is the forum expert (unfortunately for him ).

 

As stated, 55 psi is perfect, whereas your mechanic is not. Best get rid!

Richard

 

Thanks for all the replies, and I haven't done much self-mechanical auto work since point ignition & carburetors, but I am catching up.
My OP wasn't clear for all to understand.
Within 25-50 miles of purchase I had 2 issues CEL and reduced performance display
1- a vacuum leak (Supercharger bypass valve actuator) the diaphragm was rotted out , had to replace with used part as it is not available new.
2- p0193 code, fuel rail pressure sensor was replaced, as well as the fuel filter.

Now I am trying to get it smog tested, California requires this with a change of ownership.
Currently driving to allow ECM/ECU to record air/fuel values for the test, but I am getting periodic CEL and P0193 code.
To my knowledge I can't pass a test with a stored code, and I believe erasing the code will erase all smog data.

I will need to get a basic scanner to read codes, advise on purchase is good! I do have multimeters to check electrics.

For the high pressure code I assume,
1- The fuel rail pressure sensor that was replaced is bad,
2- Fuel pump pressure regulator is bad
3- fuel pump control module is bad
4- Electrical connection somewhere in this system is giving me trouble

Now I think I can get better advice, Thank you!
2003 XKR 4.2 SC, convertible

 

You can pass with a stored code. All monitors must be set and the CEL must not be on. If those two criteria are met, you'll pass.

 

That is good news and thank you!
It does run great

 

A simple and effective basic scanner is a "torque pro" and you can find it easily on Amazon. Have it in a day. Plug it in and see what you're seeing...

The only possible REALLY no fun thing is the pressure relief valve on the fuel pump assembly...

If you can pull into a inspection station and you don't have a light on I think you might be alright.

 

Alan, that was done. Thanks

 

Thanks Jay, I will look into that scanner

 

If you have no MIL (aka CEL) ignore any stored codes (*). If smog due do NOT clear codes as you clear all the OBD monitors most smogs need to be set!

(*) they will eventually be auto-deleted anyway

 

I have been reading other threads on related issues and may have found the problem.
I removed the vacuum line from the Fuel Rail Pressure Sensor (FRPS) and discovered that the plastic fitting for the vacuum line is solid,
IT HAS NO HOLE in it for vacuum to operate the sensor. This is a Ford labeled sensor.

I think I will have the shop supply me with a replacement!

 

Post up a photo of this. I would like to see what you're seeing...

 

Jay, I will post a picture as soon as I remove it. I am currently at work. Looking at the end of the vacuum nipple, is like looking at the eraser end of a pencil, no hole!

🤣

 

I contacted the shop and mentioned my observation and advised NDK replacement for the FRPS.
Then I removed the sensor and found that it does have a pinpoint vent hole, not what I assumed!
Shop told me to bring it in and they would replace it and do some tests.
So they are doing a good job for me, and I am an idiot,

 

Success!
After much research on this forum I tried a hard reset at battery cables.
It cleared codes, reset ECM to factory specs.
Now it set all monitors in 2-10 mile drives, and am getting no codes.
Got it smoged today and all is well.

Much thanks to all you knowledgeable members!!