Lowside fuel pressure sensor almost claimed another victim for the second time....
Customer had reached out to us to see if we had an engine to get him back up and running quick. We just so happen to have a fresh drop-out from a customers Ecoboost Mustang. Did a headgasket/studs and Precision Drop-In Turbo upgrade and shipped it out to him.
He got it all in and I gave him things to look out for to see if the low pressure sensor that I posted about the other day might have been the cause of failure previously.
Sure enough, he got everything back together and did a test log and the fuel pressure plummeted and the car went dead lean.
If I didn't catch this the other day and gathered the signs he might have been dealing with yet another engine failure.
Here is a link I found where Ford did a recall because they were "leaking". Not sure if they actually were leaking but by design it would almost be impossible for it to leak unless the o-ring wasn't in the threaded portion which I can't really see happening.
Looks like the Ford recalled requested dealers to install a new fuel line part number# FR3Z-9J280-A
However it looks like this line was superseded by a new part number but I'll have to get that tomorrow.
Here are the symptoms to look out for. I figured I would post it again so we can try and cut down the amount of emails we are getting.
Check engine lights related to lowside fuel pressure sensor:
If you are having stumbling issues while getting into boost or the car is feeling "boggy" you might want to check the following things:
- Add "Lowside FP Actual" to your Cobb Gauges. If it doesn't read at all (0-10psi), is stuck on a number and doesn't fluctuate, or reading in the 100+ range during idle and cruising. YOUR SENSOR IS BAD.
- If it seems to read correctly (70-80psi) then set a gauge to HPFP Command and slightly get into boost. If it pegs 100% in low boost situations. YOUR SENSOR IS BAD.
- Add "FRP Actual" and "FRP Desired" To your gauges and slightly get into boost. If your desired goes into the 2000psi+ range and your actual drops to 100-300psi. YOUR SENSOR IS BAD.
These are the FOR SURE ways to test to see if your sensor is bad. Originally it looked like if it read 100psi+ on lowside pressure actual it was bad but I have came across instances where lowside was reading normal but the sensor was still faulty. It is best to do ALL THREE test to confirm your sensor is good, and to look elsewhere if you are having issues. EVEN IF YOU AREN'T HAVING ISSUES IT IS GOOD TO CHECK!
If you can get the sensor off without stripping it you can replace it with part number BU5Z-9F972-B. If you cannot get the sensor out without stripping it you will need the complete line part number FR3Z-9J280-A.