2014 Mustang GT Fuel Injector Help

[Bolt_5oh]

Let me make this brief, but thorough. I have a 2014 Mustang GT/CS that I bought in January 2024. I got it tuned by BAMA a month later, and it has been tuned by them exclusively ever since, and ran fine up until spring of this year. I have all but confirmed by multiple tests that I have a fuel issue.
Autel scan tool reading anywhere between 30-70 misfires between 2K - 3K RPM, bad hesitation and lack of power in that RPM range, both cats blown out, fuel smell in my oil, car struggling to start after sitting all day at work, and the problem seemed to completely go away after ultra sonic cleaning my injectors, only to come back WORSE 3 days later, which I believe is because one or two of the injectors problems are internal/electrical.

I have already replaced plugs and coils with FoMoCo parts, FWIW.

I am almost dead set on getting new injectors now, but no where seems to sell stock injectors other than Ford for a whopping $70/piece. Ford Performance sells LU47s for $300 right now, and they are E85 capable, which I have plenty of access to here in northeast Florida. And I am aware I have to get a new tune for both. Is that the correct route though? What if I spend the money and the problem is still there? Does anyone have any advice on how to confirm which part of my fuel system is the failing point right now? It just seems most logical that it is injectors when cleaning them "fixed it" for a few days.

 

[Juice]

Your issue is BAMA. Period.

 

[slonison]

Have you tried removing the tune and running on the oem settings?

 

[Shane361]

Have you tried removing the tune and running on the oem settings?

This is the next step in T/S.

 

[Red-Candy-Metallic]

Have you done any data logging (fuel related PIDs, i.e. fuel trims, MAF freq, MAF Flow) with your tuning device? Are they still using the SCT X4? As far as the injector cleaning goes, could contaminants in the fuel system re-introduce another issue? If cleaning the injectors solved the issue previously, perhaps a product like Royal Purple Max-Clean Fuel System Cleaner and Stabilizer is worth a shot. As far as fuel goes, are you religiously using top tier detergent fuel, i.e. Shell, Chevron, Mobile? If you smell fuel in the oil, could an injector be leaking when the engine is not running, hence the fuel smell in oil and perhaps a flooding condition on cold start. That would make me concerned about the oil quality as well. If you do replace the injectors, the difference in price (FPP vs. stock) would pay for the tune update if required. Does the car have any modifications that require the BAMA tune?

Forgive me if this all seems obvious or that I have misunderstood your issue. Regardless, I hope that you find a solution to this problem.

 

[slonison]

Man, I'm terrified to plug anything into my car. Single owner, 97k miles bought new in 2013. Never done anything more than oil changes.

 

[DieHarder]

Did you do anything to the car (update tune, replace plugs, etc) prior to symptoms showing up? At some point may be worth having a diagnostic scan by the dealer. In my case a dealer scan said I had two bad coils after I installed new plugs and an entire set coils. Had the same running symptoms as you (bad misfires 2 - 3k range). Replaced the offending coils and all good now.

 

[GlassTop09]

Let me make this brief, but thorough. I have a 2014 Mustang GT/CS that I bought in January 2024. I got it tuned by BAMA a month later, and it has been tuned by them exclusively ever since, and ran fine up until spring of this year. I have all but confirmed by multiple tests that I have a fuel issue.
Autel scan tool reading anywhere between 30-70 misfires between 2K - 3K RPM, bad hesitation and lack of power in that RPM range, both cats blown out, fuel smell in my oil, car struggling to start after sitting all day at work, and the problem seemed to completely go away after ultra sonic cleaning my injectors, only to come back WORSE 3 days later, which I believe is because one or two of the injectors problems are internal/electrical.

I have already replaced plugs and coils with FoMoCo parts, FWIW.

I am almost dead set on getting new injectors now, but no where seems to sell stock injectors other than Ford for a whopping $70/piece. Ford Performance sells LU47s for $300 right now, and they are E85 capable, which I have plenty of access to here in northeast Florida. And I am aware I have to get a new tune for both. Is that the correct route though? What if I spend the money and the problem is still there? Does anyone have any advice on how to confirm which part of my fuel system is the failing point right now? It just seems most logical that it is injectors when cleaning them "fixed it" for a few days.

Hi Bolt_5oh,

From reading your post, you're in the ball park concerning your symptoms\cause.......excess fuel usage, but there are 2 systems w\ these S197's that can cause this.......you've ID'd 1 of them--fuel injectors, but you're ignoring the other 1 & this is the EVAP system, most prominent when after the fuel tank is fully filled, using the often used habit of continuing to keep clicking the fuel dispenser handle to "fully top off the tank" causing excess fuel to potentially get sent thru the filler tube vent line bypassing the fuel tank & sending raw fuel straight to the EVAP canister which then can get drawn into the IM thus flood the engine as well causing the very same issues you're seeing.

So, in order to help you effectively, you need to do this to eliminate the EVAP system as a cause.......STOP continuously clicking the fuel dispenser to "top off the fuel tank" after the handle clicks off on its own the 1st time. These 05-14 S197's are bad about loading the EVAP canister w\ raw fuel from this habit......all of them from 05 thru 14 will do this........the OM even tells limit doing this to 2 clicks max........but I can exclusively inform you that even this is too much........I have recorded evidence of this EVAP system doing exactly this thru a datalog after filling the fuel tank fully & doing the 2 click method that the OM tells you to do.......this doesn't work......the only thing that DOES work is to STOP the habit completely.......when the handle clicks off on its own, pull it out & hang it up........period, end of story.

Not only will doing this stop this issue thru the EVAP system of getting raw fuel into your IM, but it will also help you to NOT ruin your EVAP canister itself........the #1 way to screw up your EVAP canister is to keep pushing raw fuel into it........this will break down the charcoal inside it & plug it off internally.

To check this, simply disconnect the plastic corrugated flex line from the EVAP canister (this line is going to the CPV under the hood.........) & see if raw fuel comes out (lowest point in this line\system......), if dry, then this isn't a cause--if not then someone is guilty of overfilling the fuel tank & causing this to become a cause of your symptoms...........

This 1 is the free suggestion\recommendation to do....................

Now for the fuel injectors....................

Do this at this point..........pull the fuel injectors\fuel injector rails out\off of IM & prop them up so that the nozzles on both sides are clearly visible--do not remove the injectors from the rails & DO NOT detach the fuel line from the rails & DO not disconnect the connectors from the injectors........you'll need to use the fuel pump to pressure up the rails to then check the injectors for leaks w\ 12v+ power running thru them. Put some light blue colored towels\rags under the nozzles so that if any nozzle(s) is\are leaking, you can SEE it\them.

This will be doing 2 checks at the same time.......both circuit-wise (the ECU can only check the injector circuits for circuit issues only......not the injector pintles themselves for sealing......FRP can give some info depending on how bad the leaks are but not reliable, so the only reliable method is visual inspection under pressure....) AND visual (the definite method to use to check for injector leaks........). The 12v+ power thru them is needed to ensure that the leak isn't being caused by a wayward ECU injector driver switching diode pulling a slight - grd thus is energizing the injector coil just enough causing it to pull off the seat...........

Now hook up your scan tool & set it to monitor the fuel rail pressure PID thru live data, then turn the ignition to KOEO (key on, engine off.......) so the fuel pump will run to load the rails then turn off, then check the FRP to ensure that the rails are fully pressured up (between 39 thru 43 psi nominal for OEM Ford return less type fuel system, if FRP is higher than 50 psi, then you've found another potential issue that can be influencing your symptoms--injectors over injecting fuel into engine due to too high DPOI thus the ECU can't compensate enough.........potential FRP sensor issue or tune cal issue......check the manifold vacuum line at the FRP sensor for raw fuel 1st........should be dry.....if wet then FRP sensor is bad............) & then visually check all 8 injectors for any signs of fuel leaking out of them w\ 12v+ power running thru them...........if you visually see no leaking & FRP is in the good range, then you're done........the fuel injectors themselves & ECU injector driver switching diodes aren't your issue.

Now if you DO see any injectors leaking after the rails are loaded up, then disconnect the leaking injector's connector to open the circuit thru it then see if the leak stops or keeps going.........if it keeps going, then the injector is bad.........if it stops, then you have an issue at the ECU board's injector driver switching diode going bad (these fuel injectors are operated thru ECU PWM grd switch control--ECU pulls the circuit to grd using a switching diode thus energizes the injector coil to pull the pintle off the seat so fuel will flow......this is very rare but NOT impossible....thus why you need to check for this in the manner that I posted.......if found to be the cause then you'll need an ECU replacement..........repeat again, usually not the cause but these cars are getting old thus do not assume that this isn't going on.........why the testing procedure I've laid out........electronics do age out over time--ECU being located under the hood ain't the best place for electronics living long lives........).

Then after any replacements are done ((if you find more than 1 injector bad......then I suggest to replace them all & ONLY use either 1.) the OEM Ford replacements from the dealership OR 2.) order the Ford Performance M-9593 LU47 replacement kit w\ the matching Ford M-9593 LU47 injector data sheet......)), perform a retest of the fuel injector system as described prior to verify the repairs before going any further............

FYI, injectors aren't the area to be looking for cost savings.................especially w\ Ford ECU's or any ECU to be honest...............

IMHO, before you go to lengths to call a tune cal into question.......even BAMA, you NEED to PROVE that none of this posted here ISN'T happening.........not assume it, thus the only methods that can quickly get to some resolution w\o making any assumptions is to do what I've posted here. Only after proving all this out prior...........do you then begin to start looking at a non-Ford OEM-tuned tune cal.............my 2 cents.

As for the injectors being cleaned, perform good then resume excessive fueling......then I suggest that you get a couple of bottles of GUMOUT All-In-One fuel additive to put in the fuel tank (1 bottle per full tank of fuel, so do this at least 2 times...........) to clean out the system (this product has the chemical PEA in it which is proven to clean out the fuel system including fuel injectors---the same chemical used in all Top Tier fuels as an injector cleaning detergent.......invented by Chevron FYI........the Chevron Techron fuel additives also have PEA in them.......essentially read the labels on the bottles--if the labels DO NOT list that the chemical PEA is in the product......leave it in the store.....) in tandem w\ a fuel filter changeout to try to clean the system up as a last resort w\o having to open up the fuel tank to physically clean all out (your posted symptoms indicates a potentially dirty fuel system........).

Do this AFTER you prove out the injectors\EVAP system........not before.........don't try to shortcut the process............

Hope this helps..............the ball is now in your court.................

 

[Bolt_5oh]

Have you tried removing the tune and running on the oem settings?

Yep. Twice, in fact. It still does it. Even ran a tank of 87 octane some time in April/May on the stock tune, same thing.

 

[Bolt_5oh]

Have you done any data logging (fuel related PIDs, i.e. fuel trims, MAF freq, MAF Flow) with your tuning device? Are they still using the SCT X4? As far as the injector cleaning goes, could contaminants in the fuel system re-introduce another issue? If cleaning the injectors solved the issue previously, perhaps a product like Royal Purple Max-Clean Fuel System Cleaner and Stabilizer is worth a shot. As far as fuel goes, are you religiously using top tier detergent fuel, i.e. Shell, Chevron, Mobile? If you smell fuel in the oil, could an injector be leaking when the engine is not running, hence the fuel smell in oil and perhaps a flooding condition on cold start. That would make me concerned about the oil quality as well. If you do replace the injectors, the difference in price (FPP vs. stock) would pay for the tune update if required. Does the car have any modifications that require the BAMA tune?

Forgive me if this all seems obvious or that I have misunderstood your issue. Regardless, I hope that you find a solution to this problem.

Thanks for the thorough reply. Let me answer everything I can.

My dad has datalogging software on his laptop that we used while we were driving cross country to Florida. It was showing it was running way rich and misfiring like crazy first thing in the morning. The car would always drive worse after stopping somewhere and starting the car again. That's why I really think it's a leaky injector, but trying to get as much information as I can before making that call.

Still using SCT X4, yes.

I only use Shell V-power. Same station, same pump, every Friday.

Not sure if you're referring to the oil that I'm using or just concern about it's ability to lubricate properly with fuel mixed in, but if you're referring to what oil I use it's Quaker State 5W-30 Full Synthetic.

No modifications that require a tune, although I have 245/45R18 tires (that I really need to get rid of and swap for 19s) and use the tune so my speedo is correct. I have also confirmed the problem is present with and without the tune. Though I really want to just bite the bullet and go pay Palm Beach Dyno to tune my car. I'm kind of tired of BAMA at this point. The on and off accelerator leaves a lot to be desired.

 

[Bolt_5oh]

Did you do anything to the car (update tune, replace plugs, etc) prior to symptoms showing up? At some point may be worth having a diagnostic scan by the dealer. In my case a dealer scan said I had two bad coils after I installed new plugs and an entire set coils. Had the same running symptoms as you (bad misfires 2 - 3k range). Replaced the offending coils and all good now.

Negative. I turned my car on to go to work one morning and it was running rough. Consistently gotten worse ever since. Only just did plugs and coils last week at 114k miles. But it didn't fix anything unfortunately. At least I know they're done though.

 

[Bolt_5oh]

Hi Bolt_5oh,

From reading your post, you're in the ball park concerning your symptoms\cause.......excess fuel usage, but there are 2 systems w\ these S197's that can cause this.......you've ID'd 1 of them--fuel injectors, but you're ignoring the other 1 & this is the EVAP system, most prominent when after the fuel tank is fully filled, using the often used habit of continuing to keep clicking the fuel dispenser handle to "fully top off the tank" causing excess fuel to potentially get sent thru the filler tube vent line bypassing the fuel tank & sending raw fuel straight to the EVAP canister which then can get drawn into the IM thus flood the engine as well causing the very same issues you're seeing.

So, in order to help you effectively, you need to do this to eliminate the EVAP system as a cause.......STOP continuously clicking the fuel dispenser to "top off the fuel tank" after the handle clicks off on its own the 1st time. These 05-14 S197's are bad about loading the EVAP canister w\ raw fuel from this habit......all of them from 05 thru 14 will do this........the OM even tells limit doing this to 2 clicks max........but I can exclusively inform you that even this is too much........I have recorded evidence of this EVAP system doing exactly this thru a datalog after filling the fuel tank fully & doing the 2 click method that the OM tells you to do.......this doesn't work......the only thing that DOES work is to STOP the habit completely.......when the handle clicks off on its own, pull it out & hang it up........period, end of story.

Not only will doing this stop this issue thru the EVAP system of getting raw fuel into your IM, but it will also help you to NOT ruin your EVAP canister itself........the #1 way to screw up your EVAP canister is to keep pushing raw fuel into it........this will break down the charcoal inside it & plug it off internally.

To check this, simply disconnect the plastic corrugated flex line from the EVAP canister (this line is going to the CPV under the hood.........) & see if raw fuel comes out (lowest point in this line\system......), if dry, then this isn't a cause--if not then someone is guilty of overfilling the fuel tank & causing this to become a cause of your symptoms...........

This 1 is the free suggestion\recommendation to do....................

Now for the fuel injectors....................

Do this at this point..........pull the fuel injectors\fuel injector rails out\off of IM & prop them up so that the nozzles on both sides are clearly visible--do not remove the injectors from the rails & DO NOT detach the fuel line from the rails & DO not disconnect the connectors from the injectors........you'll need to use the fuel pump to pressure up the rails to then check the injectors for leaks w\ 12v+ power running thru them. Put some light blue colored towels\rags under the nozzles so that if any nozzle(s) is\are leaking, you can SEE it\them.

This will be doing 2 checks at the same time.......both circuit-wise (the ECU can only check the injector circuits for circuit issues only......not the injector pintles themselves for sealing......FRP can give some info depending on how bad the leaks are but not reliable, so the only reliable method is visual inspection under pressure....) AND visual (the definite method to use to check for injector leaks........). The 12v+ power thru them is needed to ensure that the leak isn't being caused by a wayward ECU injector driver switching diode pulling a slight - grd thus is energizing the injector coil just enough causing it to pull off the seat...........

Now hook up your scan tool & set it to monitor the fuel rail pressure PID thru live data, then turn the ignition to KOEO (key on, engine off.......) so the fuel pump will run to load the rails then turn off, then check the FRP to ensure that the rails are fully pressured up (between 39 thru 43 psi nominal for OEM Ford return less type fuel system, if FRP is higher than 50 psi, then you've found another potential issue that can be influencing your symptoms--injectors over injecting fuel into engine due to too high DPOI thus the ECU can't compensate enough.........potential FRP sensor issue or tune cal issue......check the manifold vacuum line at the FRP sensor for raw fuel 1st........should be dry.....if wet then FRP sensor is bad............) & then visually check all 8 injectors for any signs of fuel leaking out of them w\ 12v+ power running thru them...........if you visually see no leaking & FRP is in the good range, then you're done........the fuel injectors themselves & ECU injector driver switching diodes aren't your issue.

Now if you DO see any injectors leaking after the rails are loaded up, then disconnect the leaking injector's connector to open the circuit thru it then see if the leak stops or keeps going.........if it keeps going, then the injector is bad.........if it stops, then you have an issue at the ECU board's injector driver switching diode going bad (these fuel injectors are operated thru ECU PWM grd switch control--ECU pulls the circuit to grd using a switching diode thus energizes the injector coil to pull the pintle off the seat so fuel will flow......this is very rare but NOT impossible....thus why you need to check for this in the manner that I posted.......if found to be the cause then you'll need an ECU replacement..........repeat again, usually not the cause but these cars are getting old thus do not assume that this isn't going on.........why the testing procedure I've laid out........electronics do age out over time--ECU being located under the hood ain't the best place for electronics living long lives........).

Then after any replacements are done ((if you find more than 1 injector bad......then I suggest to replace them all & ONLY use either 1.) the OEM Ford replacements from the dealership OR 2.) order the Ford Performance M-9593 LU47 replacement kit w\ the matching Ford M-9593 LU47 injector data sheet......)), perform a retest of the fuel injector system as described prior to verify the repairs before going any further............

FYI, injectors aren't the area to be looking for cost savings.................especially w\ Ford ECU's or any ECU to be honest...............

IMHO, before you go to lengths to call a tune cal into question.......even BAMA, you NEED to PROVE that none of this posted here ISN'T happening.........not assume it, thus the only methods that can quickly get to some resolution w\o making any assumptions is to do what I've posted here. Only after proving all this out prior...........do you then begin to start looking at a non-Ford OEM-tuned tune cal.............my 2 cents.

As for the injectors being cleaned, perform good then resume excessive fueling......then I suggest that you get a couple of bottles of GUMOUT All-In-One fuel additive to put in the fuel tank (1 bottle per full tank of fuel, so do this at least 2 times...........) to clean out the system (this product has the chemical PEA in it which is proven to clean out the fuel system including fuel injectors---the same chemical used in all Top Tier fuels as an injector cleaning detergent.......invented by Chevron FYI........the Chevron Techron fuel additives also have PEA in them.......essentially read the labels on the bottles--if the labels DO NOT list that the chemical PEA is in the product......leave it in the store.....) in tandem w\ a fuel filter changeout to try to clean the system up as a last resort w\o having to open up the fuel tank to physically clean all out (your posted symptoms indicates a potentially dirty fuel system........).

Do this AFTER you prove out the injectors\EVAP system........not before.........don't try to shortcut the process............

Hope this helps..............the ball is now in your court.................

I genuinely appreciate your lengthy reply. And will try to do this test for a leaky injector.

When it comes to "clicking past full", guilty as charged. I've done it a few times. But it's been months now, because I was told by a mechanic the exact thing you're saying, so I stopped. I don't have any codes. But how else can I test if I've screwed up the EVAP canister?

 

[diambo4life]

I will sell you my stock injectors for cheap. Message me.

Have you pulled your plugs and inspected them? Anytime I have ever had misfire issues, I look at ignition first.

 

[Bolt_5oh]

Update:

I got a set of Ford Performance LU47 Injectors for free, and also had a Boss 302 intake from my dad's old car laying around and thought I'd do both at the same time. Adjusted tune, started the car hoping for the problem to be gone... NOPE. Still remains. Misfires quite bad up until 3,000 RPM with some nice (rice) pops and crackles, after that or under WOT there is no misfires.

Just pulled plugs today to check for anything out of the ordinary. Still clean, put back in and torqued to 12 ft-lbs.

What else should I test for? Autel scan tool was reading misfires on multiple cylinders (can't remember exactly which ones, but I know 4 and 6 were two of them), yet the CEL has STILL not come on.

I'm at my wits end, and I don't want to just pour money into the car if I don't need to.