4.6 spitting o-rings out of 2 injectors

[highplace11]

A little bit of SyperLube silicone on the O-rings and always replace them especially on an older vehicle... MAKE SURE there isn't one stuck in the rail or intake, I've seen them double stacked like that.... It should feel like a snap-in positive feedback action when they pop in and are secure.......

Mark

 

[skidad]

thanks! definitely put some o-ring lube on them. I got it all installed last night. I put 6 of the clips on (all the drivers side and the 2 easy ones of the passenger side) - i guess I don't understand these clips that much b/c they don't seem to hold much vertically. Maybe they just help hold everything still and straight. Anyhow I had them and it made my wife feel safer that they are on. I took the stang for a good rip last night and everything seems good - i also check my fuel rail pressure on the reader I have it it holds around 40 give or take. Unless something changes I think I'm good to go

 

[highplace11]

thanks! definitely put some o-ring lube on them. I got it all installed last night. I put 6 of the clips on (all the drivers side and the 2 easy ones of the passenger side) - i guess I don't understand these clips that much b/c they don't seem to hold much vertically. Maybe they just help hold everything still and straight. Anyhow I had them and it made my wife feel safer that they are on. I took the stang for a good rip last night and everything seems good - i also check my fuel rail pressure on the reader I have it it holds around 40 give or take. Unless something changes I think I'm good to go

Glad to hear it... The clips make it easier to prepare the rail to go in as one assembled unit as opposed to fighting with the individual injectors or having some slip or get pushed/pulled out installing/uninstalling... Plus it's nice when/if they all stay on when you pull the rail off to prevent fuel spillage, etc...

Mark

 

[skidad]

so it's been 3 days of consistent driving and the problem is back - the fuel rail lifted and bent the support 10 degrees. I feel like something with heat soak and/or fuel pressure not relieving is happening. See the last 3 post from this other thread he had the same issue: https://stangnet.com/mustang-forums/threads/crazy-fuel-issue-lifting-fuel-rails.930990/#post-9467209

I took a lot of time to use the correct fresh o-rings and made everything level. I don't know if it's too much fuel pressure when starting or fuel not draining back - i feel like it's the later. I don't know the history of the vehicle but I'm assuming the fuel pump is original.

any suggestions?

 

[Noobz347]

Compare a mechanical fuel-pressure gauge with the scanner’s fuel rail pressure reading during key-on priming and cranking; with the engine off, they should closely agree. If the gauge shows high pressure while the scanner reports normal or low pressure, suspect the fuel rail pressure sensor (FRPS), its wiring, or its vacuum reference. Check its connector and vacuum hose; gasoline in that hose indicates a ruptured sensor diaphragm. Also monitor mechanical pressure after a hot shutdown to catch a pressure rise that a normal running reading could miss.

The FRPS tells the ECU what pressure exists across the injectors, and the ECU adjusts pump output accordingly. A sensor falsely reporting low pressure can cause the ECU to command more pump output than needed. The mechanical gauge independently checks that feedback. While running, account for manifold vacuum because scanner pressure and gauge pressure may use different references.

 

[skidad]

i will pick up a mechanical gauge and do that and also check the sensor voltage and vaccum, etc. This is the picture I took this morning - same #6 injector (see black o-ring popping out) I guess I can rule out wrong bad o-rings since they were brand new motorcraft

 

[squeak93]

Silly question - I'm assuming you've taken the rail off completely and purged/cleaned the inside of it fully?

Aside from that I'm with Noobz on that there is a restriction elsewhere in the system causing a huge spike/pressure backlog and it has to go somewhere eventually. I might advise a new rail (tons of them avail out there) and possibly cleaning the entire line system - plus drop tank to make sure vent/bleed off etc are all working correctly. This of course after putting gauges on it to validate there is in fact a large pressure spike/issue.

 

[skidad]

i didn't disconnect it from the cross over fuel line but I look inside the ports and was very clean and no burs or deformations that I could see. I would have but wasn't sure if I was going to bugger up the fuel line being 25 years old.

 

[squeak93]

i didn't disconnect it from the cross over fuel line but I look inside the ports and was very clean and no burs or deformations that I could see. I would have but wasn't sure if I was going to bugger up the fuel line being 25 years old.

I would start by taking the rail all the way off the car. The disconnects are cheap from oriellys/autozone and always good to have on hand. Rail will come off pretty easy with intake tube removal and maybe a vac line or two (have not messed with a 2v in a while). Air/cleaner something through the rail to make sure there isn't some crazy obstruction in it. Reinstall with new orings and then pressure test with gauges as advised. If high pressure is present but you KNOW the rail is clear (by cleaning etc) then start looking upstream the feed line OR at the tank on the pressure relief.

 

[Mustang5L5]

Fuel pressure is a data PID that you can track in an obd2 scan tool. A simple reader will read instant data, some of the better ones will let you graph it over time so you can see spikes. I believe ForScan will let you plot a graph too if you have that software.

I find it interesting that your rail is lifting. Do you have a post of the lift/bend? I grabbed the rail and gave it a pretty good pull up and it's solid on my car. i don't see how it would lift.

 

[highplace11]

I agree to check the fuel pressure for peace of mind but man if it's bending the rail... HMMMMMM... Your car uses a FPDM module that controls fuel pressure by regulating the voltage sent to the pump in the tune/calibration.... My concern is if the car is running and driving fine it seems unlikely the pressure is high enough to bend the raid... Are the hold down screws solid, not stripped, etc?!?... I suppose that would be too obvious, if that rail bent once it may be just stressed metal now, wish I could see it when it happens... Do you have a good handheld scanner???

Mark

 

[skidad]

so far tonight I put everything back and tested the fuel pressure - it's around 40 give or take a few psi depending on throttle. I saw a high of 46 and one drop down to 27 when in the parking lot reving lightly - driving it around it was 37-42 petty consistent. This is with a cheap handheld reader.

I bought a fuel pressure gauge and could not get it to show more that a few psi. I had tried this a month ago with a rented gauge and thought it was broken but apparently my Schrader valve is bad. No gas smell of gas in the vacuum tube on the FRPS. the bolts and thread are mint. Took it for a 5 min right and no isssue but will check the rail in an hour. I ran out of time today

 

[highplace11]

so far tonight I put everything back and tested the fuel pressure - it's around 40 give or take a few psi depending on throttle. I saw a high of 46 and one drop down to 27 when in the parking lot reving lightly - driving it around it was 37-42 petty consistent. This is with a cheap handheld reader.

I bought a fuel pressure gauge and could not get it to show more that a few psi. I had tried this a month ago with a rented gauge and thought it was broken but apparently my Schrader valve is bad. No gas smell of gas in the vacuum tube on the FRPS. the bolts and thread are mint. Took it for a 5 min right and no isssue but will check the rail in an hour. I ran out of time today

The valve uses a Ford special sized adapter, you can't rent the tool without the proper fitting available online... Your fuel pressure is dead spot on pressure wise via the scanner.... Are you sure the composite manifold isn't cracked or anything, if not you need a new rail, something isn't right if its been bent... They are pretty tough, should not be possible without some major other factor.... Check the fittings that hold it to the plastic manifold are not loose, no other logical explanation....

Mark

 

[skidad]

The valve uses a Ford special sized adapter, you can't rent the tool without the proper fitting available online... Your fuel pressure is dead spot on pressure wise via the scanner.... Are you sure the composite manifold isn't cracked or anything, if not you need a new rail, something isn't right if its been bent... They are pretty tough, should not be possible without some major other factor.... Check the fittings that hold it to the plastic manifold are not loose, no other logical explanation....

Mark

Both testers had the ford adapter. But maybe I’m doing something wrong. It’s our first Ford sportscar

 

[Noobz347]

If it's the kind that attached to the rail port, just remove the valve core (don't lose it) and install the mech gauge.

 

[highplace11]

Both testers had the ford adapter. But maybe I’m doing something wrong. It’s our first Ford sportscar

Show us how you are testing manual pressure....

Mark

 

[Noobz347]

Did I see somewhere that the original rail bracket was damaged or was that somebody else?

 

[highplace11]

Did I see somewhere that the original rail bracket was damaged or was that somebody else?

Yes bent and repaired maybe several times, thank you Noobz347... Not my thread but my thoughts.... Something ain't right about that situation....

We will figure it out, that' s what we do here.... Everyone is trying their best yes...

Mark

 

[Noobz347]

Yes bent and repaired maybe several times, thank you Noobz347... Not my thread but my thoughts.... Something ain't right about that situation....

We will figure it out, that' s what we do here.... Everyone is trying their best yes...

Mark

My thought would be to get online and find one to replace it with.

 

[skidad]

I'm going to swap out the core in the Schrader valve tonight when I get home so i can get a fuel pressure reading. The valve on this is just like one on a tire valve stem. I'm connecting the ford adapter to this and then connecting the fuel gauge to the adapter. it must be gunked up or buggered up is my guess.

as for bending, it's just the bracket that is bending not the rail. It might have lost it's mojo but it really seems like something else is going with fuel pressure not relieving to me b/c it's not happening when driving - all 3 times we found the leak was in the garage after driving it and it sits.

if someone knows of a source for a rail I'm open to it - i could only find an iffy one on ebay so far.