Running lean and detonation

[accel]

I would be interested in this. I changed out the plugs a few months ago and no change.

I found this https://performanceparts.ford.com/part/M-12029-M52 .

Expensive, but I might do some shoppi g for a better price around and get those.

How difficult will it be to replace coils? I've heard some spark plugs are pita, but would just couls be different? Or, would it be better to replace sparks and coils?

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[Kong76]

Coils should be really easy. The only plug thats difficult is #4 on the firewall near battery tray. I would pull a front plug and look at itd condition. If its good then just try the coil packs. Just make sure they are the right coil packs. I know half way through 16' build they changed so I have my work cut out.


* looks like those might work for me as its build date 2/24/16 to 2017. My build says 5/8/16.

 

[accel]

Coils should be really easy. The only plug thats difficult is #4 on the firewall near battery tray. I would pull a front plug and look at itd condition. If its good then just try the coil packs. Just make sure they are the right coil packs. I know half way through 16' build they changed so I have my work cut out.


* looks like those might work for me as its build date 2/24/16 to 2017. My build says 5/8/16.

I ordered a set. Will update once it arrives. As of now my power pack is uninstalled, but if this coil set gives me hope, I'll give it another try.

 

[Kong76]

I ordered a set. Will update once it arrives. As of now my power pack is uninstalled, but if this coil set gives me hope, I'll give it another try.

Right on, curious to what happens. I still have the kit on so very interested if you do end up putting it back on to see if it eliminates it. I haven't heard any detonation while I was stock. Atleast nothing that sounds like this.

 

[accel]

Right on, curious to what happens. I still have the kit on so very interested if you do end up putting it back on to see if it eliminates it. I haven't heard any detonation while I was stock. Atleast nothing that sounds like this.

I'm stock and no detonation either.

There must be some differentiation between cars that do not detonate on 91 and those that detonate on 93. If someone established coil dependency I'll try that.

Other than that my theory is that manifolds might have slight cracks and suck air.

 

[Kong76]

I'm stock and no detonation either.

There must be some differentiation between cars that do not detonate on 91 and those that detonate on 93. If someone established coil dependency I'll try that.

Other than that my theory is that manifolds might have slight cracks and suck air.

Mine was removed and reinstalled at the dealer during work so wouldn't be surprised if it is.

 

[ugstang17]

Late comer here. 1st in your earlier statement you indicated that LTFT reads 10 and STFT reads 0, That would be adpative learning correcting through LTFT to bring STFT back to or near 0. That's how it works. LTFT is a long term change that corrects STFT. As you stated once LTFT goes above 25 then you flag a code lean/rich.

I see nothing about knock. What is the knock PID doing? I would expect it to be pulling timing like crazy. This along with the lean condition would point not to coils but to fueling and timing.

How many miles is on the car? Have you changed the fuel filter recently? I did not see anything mentioned about that skimming the thread. The car now needing more fuel may be starving due to a partially clogged filter where as the restriction was not enough on the stock tune to be an issue.

Another concern is UNMETERED air and not so much a vacuum leak. Your trims beign the same throughout the operating range indicate no vacuum leak. You say nothign of a high idle which is also symptomatic of a vacuum leak. So something else here to verify is that ALL conncections between the TB and the MAF are properly made and snug. Second make sure that the gasket on the TB is in place. Any place between the MAF and the intake that leaks is potentially unmetered air. A leak in this area woudl not likely be seen on a vacuum gauge either. Your LTFT's being the same on both banks also points to something in common with both sides. So you can rule out individual COP or plug or FI issues. That leaves you unmetered air, low fuel volume, and/or poor air and fueliing tables in the tune.

Best of luck. I don't know much but I know a little. Hope this helps.

 

[Kong76]

Late comer here. 1st in your earlier statement you indicated that LTFT reads 10 and STFT reads 0, That would be adpative learning correcting through LTFT to bring STFT back to or near 0. That's how it works. LTFT is a long term change that corrects STFT. As you stated once LTFT goes above 25 then you flag a code lean/rich.

I see nothing about knock. What is the knock PID doing? I would expect it to be pulling timing like crazy. This along with the lean condition would point not to coils but to fueling and timing.

How many miles is on the car? Have you changed the fuel filter recently? I did not see anything mentioned about that skimming the thread. The car now needing more fuel may be starving due to a partially clogged filter where as the restriction was not enough on the stock tune to be an issue.

Another concern is UNMETERED air and not so much a vacuum leak. Your trims beign the same throughout the operating range indicate no vacuum leak. You say nothign of a high idle which is also symptomatic of a vacuum leak. So something else here to verify is that ALL conncections between the TB and the MAF are properly made and snug. Second make sure that the gasket on the TB is in place. Any place between the MAF and the intake that leaks is potentially unmetered air. A leak in this area woudl not likely be seen on a vacuum gauge either. Your LTFT's being the same on both banks also points to something in common with both sides. So you can rule out individual COP or plug or FI issues. That leaves you unmetered air, low fuel volume, and/or poor air and fueliing tables in the tune.

Best of luck. I don't know much but I know a little. Hope this helps.

I thought our fuel filters arent serviceable?

I don't have a way to look at the knock sensors. I did lean towards fuel delivery and was looking at a drop in upgraded pump. I will double check all connections again. I used butane gas around throttle body and the spacer the FRPP 2 kit came with and no changes. The octane booster seems to help quite a bit but does not eliminate it completely.

 

[ugstang17]

Well sir, I have been wrong before but a car not having a fuel filter would be a first in my 55 years of experience. Rock Auto shows a motorcraft fuel filter in stock and listed for a 2017 Mustang GT. This link clearly shows one as well. FOrd has done some stupid things over the years and some wise things. I don't think eliminating a fuel filter would fit in either category. The link below shows the location for an S550.

https://www.mustang6g.com/forums/attachments/fuel-filter-change-jpg.169318/

Your Butane method is a good process. Its been used by race enthusiasts who do their own wrenching for years. I used the same method on my 2005 when I develope a problem I was troubleshooting. It works. Do not doubt the process. You can also purchase a vacuum hand pump with a gauge on it to pull down a vacuum on the car as well to check for vacuum leaks. I also used one of those as a secondary test that concluded no leaks. So again your problem IMHO is tuning or fuel related. Good luck.

 

[accel]

So again your problem IMHO is tuning or fuel related. Good luck.

Ford Racing Power Pack Tuning is standard. The issue with this tune is that some have it working just fine even on 91 octane but some have issues even with 93. I created a poll topic on it and 40% of users report detonation.

And this was the same pattern even with previous GT generation since 2011. Noone was able to troubleshoot/ fix it as far as I could find it. Ford Racing hasn't came with any valuable hint either. I've spent time communicating with them.

Mine for instance, detonates as well.

This raises a question - there must be some parts on our cars that are functioning just fine on stock tune, but are out of range of specs for this tune.

If fuel filter is one of the suspects I might just replace it. That should be easy.

It would be cool to find what's out of spec.

 

[DonnieO]

Well sir, I have been wrong before but a car not having a fuel filter would be a first in my 55 years of experience. Rock Auto shows a motorcraft fuel filter in stock and listed for a 2017 Mustang GT. This link clearly shows one as well. FOrd has done some stupid things over the years and some wise things. I don't think eliminating a fuel filter would fit in either category. The link below shows the location for an S550.

https://www.mustang6g.com/forums/attachments/fuel-filter-change-jpg.169318/

Your Butane method is a good process. Its been used by race enthusiasts who do their own wrenching for years. I used the same method on my 2005 when I develope a problem I was troubleshooting. It works. Do not doubt the process. You can also purchase a vacuum hand pump with a gauge on it to pull down a vacuum on the car as well to check for vacuum leaks. I also used one of those as a secondary test that concluded no leaks. So again your problem IMHO is tuning or fuel related. Good luck.

That's for the 5.2. The 5.0 has a filter on the fuel pump only.

 

[ugstang17]

^^^ Now that is just scary and another one of my 21 reasons why I become less impressed with the S550 platform.

UPDATE _ Because I created this confusion by assumign any car built would have an in line fuel filter I contacted a friend of mine who just did an E-85 full system upgrade and he confirms he came across no inline on the original feed lines when he yanked them out. He confirms there is only the filter on the filter (or screen) in the tank. Sorry.

This really is stupid designing in my professional opinion. A GT350 is savvy to an inline as the contributor who pointed out my error indicates. So that leaves either unmetered air or fueling tables or air tables on your tune in my opinion....short of a failing fuel pump that was keeping up in stock mode but not now with the call for more fuel due to more air. Showing my age. LOL!

 

[accel]

Right on, curious to what happens. I still have the kit on so very interested if you do end up putting it back on to see if it eliminates it. I haven't heard any detonation while I was stock. Atleast nothing that sounds like this.

Apparently the price I got was too good to be true. Got my order cancelled by a retailer this morning.

At this point after additional discussion here I'm not sure if coils to be the issue. Likely the pump. So I'm not all that disappointed with order cancellation.

 

[accel]

Could it be faulty knock sensors?

Here's the link where they suggest a pretty simple check.

https://www.onallcylinders.com/2015...mination-9-ways-to-prevent-engine-detonation/

"you can test the knock sensor by tapping a wrench on the manifold near the sensor and watching for a timing change. If the timing doesn’t retard, the sensor may be bad."

 

[Kong76]

Im looking into the C8...lol