New to mustangs but I am an automotive tech, I have an 04 gt that over pressures during priming cycle koeo (90psi), once started it holds perfect fuel pressure. The car has seen internal moisture so I replaced frp sensor, ecu, fpcm, and a failed fuel pump from symptoms.. question is does anyone know own exactly how the ecu controls the fuel pump during priming?
Crazy fuel issue lifting fuel rails
- Thread starter greenhornponyguy
- Start date
More info: bone stock 4.6 with 65k on the car, there's not much I can't figure out but this one has me stumped... koeo fuel pressure spikes to 90psi resulting in lifting fuel rail off of injectors and pouring fuel all over the engine. FYI convertible car that has, im sure seen moisture since I live in the PNW... is there connectors inside the car somewhere under the carpet that I havent found ect?? All the usual suspected connectors are clean and corrosion free...
Ever get this issue fixed? I’m experiencing the exact same issue on my 2003 GT. Ford told me I’m missing all the fuel injector retention clips, but this is my 3rd New Edge Mustang and I’ve never had clips on any of them (my first was an ‘01 I bought new, so they couldn’t tell me someone removed them). I’ve blown 7 injector o-rings over the past 5 months, always due to a fuel pressure spike on cranking, and it lifts and bends my fuel rails, as well.
Yes, the injector retention clips solved my 03' GT fuel rail problems. As I noted, these were NOT installed on new SN95 'Stangs from the factory, despite my local Ford parts and service departments arguing otherwise (try to find a pic on-line of a 4.6L modular with them installed... you won't find any). It is very clear to me that Ford realized the problem here long after the last New Edge Mustang rolled off the assembly line in 2004. They made clips and added them as a normal part in their parts diagrams (as though they were installed at the factory), then silently swept the issue under the rug. Shame on Ford here, as they really should have recalled these vehicles and installed them since this is a potential fire hazard and risk to human life.
Note, though, that these appear to have been hastily made. While they really should be bent at a 90-degree angle, they are closer to 95 or 100 degrees, so they won't just fit nicely out of the package. When you buy them, expect to have to place the longer ends into a vise and gently tap the shorter ends down to 90-degrees before you install them on your fuel rails. Also, my local dealer wanted to charge me $10 apiece for them, but I found them on-line from other Ford dealers for half that, so I ordered them on-line. I would also recommend you ensure the fuel rails are not bowed at the centers and that the two mounting brackets on each side are still at 90-degrees. I removed the 4 bolts (2 on each rail), popped out all the injectors, re-installed the 4 bolts, gently tapped the rails near the mounting brackets to get them back at 90-degrees, then gently tapped the center of the rails to get them straight again (use a clean, thick, metal straight edge to test for rail straightness). Then I removed the bolts, reinstalled the injectors with fresh O-rings, remounted the rails, installed all the new retention clips (properly bent to 90-degrees), and haven't popped an O-ring since. I hope this helps you and others.
Unfortunately, Ford really did drop the ball on this one, and my respect for them wanes as they continue to make poor decisions like this. As there are now fewer SN95 and New Edge vehicles on the road, the problem is just fading into silence. Meh.
Copy that!! I will give it a try.. have you watched your fuel pressure on cranking to verify it wasn't too high of fuel pressure? Mine shows the 90 psi max of the fuel rail pressure sensor. That doesn't seem right to me. I made my own fuel rail hold downs and it stopped lifting the rails but I still get a 0193 code for frps high input once in a while.... thanks again for the reply and the detail!! Guess I will run it until something else fails and gives me more clues lol
Well, I have an Autometer fuel pressure gauge installed. I did notice that it spiked high (90, too) on crank, and it only ever blew injector O-rings on crank (never while actually driving), but around that time I noticed a grounding issue with that gauge. It was also around that time that I installed the injector clips (maybe two weeks apart). That said, it's difficult to tell if the pressure spikes were real or due to the odd grounding issue I had with the gauge (actually, all 7 of my installed Autometer gauges, as they all had odd issues and do not now). However, I do suspect the pressure issues for me were real, as about two months ago, I cranked my GT to a no-start condition. It cranked, and I could hear the fuel pump priming, but no fire up. I disconnected the fuel rail connection near the entry point of the rails and primed the pump, but no fuel. I knew the filter was good, so I looked for kinked lines quickly, then realized, "How in the world would I have a kinked fuel line anyway?!?". So, I abandoned that idea and disconnected the fuel line at the fuel filter inlet and primed again. No fuel. So... the pump was turning, but not pushing fuel. My GT is my only car (my wife was at work with hers), so I donned my running clothes and a backpack and ran 3.9 miles to OReilley's. Bought a fuel pump, then had to walk back since the box was way too big to fit in my backpack! Oh, well. I dropped the tank and removed the pump to see that the outlet hose of the pump had been blown off of the metal tube, and there was no clamp for it. My new pump had a crimped clamp on it, so I felt better about installing it. So... yes... I do now wonder if I had fuel pressure issues on crank, as I really don't see my pressure gauge hit 90 like it used to. Forgive the TL;DR. Have a good one!
The problem is aftermarket fuel pumps that do not meet Ford specification. I have a 2001 GT bought new that had no injector retaining clips and never needed them. The sequence of events: (1) you drive long enough to reach normal operating temperature. (2) 30-60 minutes after the trip the rails and fuel lines have soaked a lot of heat, which causes the gasoline to expand, which causes the pressure to rise. (3) The aftermarket fuel pump's positive pressure relief valve fails to open, or does not open sufficiently to allow some fuel to drain back into the tank, thus relieving the pressure. (4) The pressure acts like a hydraulic ram with symptoms like fuel rail bending or the top o-ring of a fuel injector being forced down far enough to break the seal and leak gasoline like crazy.
On my car there's failure of the brand new o-ring on the #6 injector. My fuel pump, which doesn't comply with Ford's specifications, is the Delphi DFG0827. I started having trouble less than 1 month/ 1,000 miles after the original fuel pump was replaced. Delphi usually is a reliable brand. Now I'm looking into replacing it with a Bosch 67170.
Ford quietly makes changes like fuel injector retaining clips. And like changing the dipstick on 4.6L engines starting 2002 along with changing the 2002 oil capacity specification to 6 quarts, without notifying owners of earlier models.
On my car there's failure of the brand new o-ring on the #6 injector. My fuel pump, which doesn't comply with Ford's specifications, is the Delphi DFG0827. I started having trouble less than 1 month/ 1,000 miles after the original fuel pump was replaced. Delphi usually is a reliable brand. Now I'm looking into replacing it with a Bosch 67170.
Ford quietly makes changes like fuel injector retaining clips. And like changing the dipstick on 4.6L engines starting 2002 along with changing the 2002 oil capacity specification to 6 quarts, without notifying owners of earlier models.
Hello, new to the forum - We bought a 2001 Mustang GT with only 14k miles this summer (all parts are original) Wondered if @greenhornponyguy had solved his issue with clips?
We have had the drivers side rail lift up 2x on us on cylinders 5 and 6. Did it about 1 month ago and I replaced top orings on injectors 5 and 6. I also bent the rail support piece back to 90 degrees. I chalked it up to previous owner. I may have pinched #6 oring when I put things back together last time b/c the other day it spit out part of the oring and lots of fuel. A little confused b/c it took a month before that happened.
I've ordered those clips (hard to find) and will be putting on 4 new orings. Luckily both times it happened in our driveway - but it has me a little nervous.
Do you think fuel pressure is an issue for me with a stock pump? do i need to check this pressure sensor? what else should I be checking? Can post pictures
thank you
We have had the drivers side rail lift up 2x on us on cylinders 5 and 6. Did it about 1 month ago and I replaced top orings on injectors 5 and 6. I also bent the rail support piece back to 90 degrees. I chalked it up to previous owner. I may have pinched #6 oring when I put things back together last time b/c the other day it spit out part of the oring and lots of fuel. A little confused b/c it took a month before that happened.
I've ordered those clips (hard to find) and will be putting on 4 new orings. Luckily both times it happened in our driveway - but it has me a little nervous.
Do you think fuel pressure is an issue for me with a stock pump? do i need to check this pressure sensor? what else should I be checking? Can post pictures
thank you
Attachments
The clips do not work. My mechanic installed them, and soon after the rail lifted enough for the #6 o-ring to go out of position. Then my mechanic said, "Oh, I realize that we did not install the clips correctly." So I returned my '01 GT to have the clips installed "correctly". Within a few days the #6 o-ring problem returned. Even if the clips did work, do we really want sky high fuel pressure in an unattended car, stressing fuel system parts and increasing fire risk?
I called tech support at Delphi (maker of my fuel pump) and spoke to a guy named Aaron who said that fuel pressure with the engine off, key removed, should be 5-10 psi due to the operation of a check valve in the fuel pump assembly. If that check valve is not working, there there is no other mechanism to relieve fuel pressure with the engine off. Aaron recommended a fuel pump replacement under warranty, and I'm returning my car to the shop today.
It is an annoyance, but what you can do until you replace the fuel pump is about 15 minutes following a trip, start the engine, count to 3 and turn it off. That will put cooler fuel in the rails and drop the pressure to about 40 psi. Depending on ambient temperature and how hot it is under the hood, you might need to repeat at 30 minutes.
If your fuel pump us sure enough the original part, then I'd like to know whether it was made by Bosch or Delphi or some other OEM supplier. Bosch claims that their current fuel pumps match the original Ford specs IF (this is a very big if) Bosch was Ford's OEM supplier for the part. But when you call Bosch tech support they will neither give you the technical specifications you need nor will they confirm or deny that they ever supplied fuel pumps to Ford for the New Edge Mustangs. So their quality assurance statement is absolutely meaningless to me.
thanks for your responses - i feel like i have the same issue- replaced the o-rings and bent everything back perfect and 3 days later the problem is back. I will do some checking on the fuel pump.
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