Question about Misfire codes Gen3

[BlueCollarDaily]

Hey guys!
Ive been tracking down P0300,P3016,P0303,7,8 codes.
Been thru checking and changing plugs/gapping, coil swaps, checked ohms on injectors. Log seems to show port duty cycle is fine on 13 psi...fuel pressures seem normal with a BAP....Lamda both banks fine. STFT and LTFT usually under 3% even when stumbling at idle and off idle..
However it does "lock up" there are times it stumbles say at idle and it flatlines in real time...spark with lock and so will STFT...say bank 2 goes a bit lean then it stumbles and all closed loop adjustments including spark just lock up and when they unfreeze, adjust and it tries to idle better..
Also one time I noted on a log at part throttle the spark struck at 35 degrees like you drew the line with a ruler during one of these freezes. It also starts at times with like 16k degrees timing for a bit, maybe just noticing this because I'm just now logging start cycles....
From idle to approximately 2700rpm I get misfire counts, idle to worst at 1450rpm...around 2700 cleans up all the way to 7300 and 13psi....
Seemingly exhausting all normal avenues so it's time to look at mechanical and my question is when the code P0303 drops, that's not cylinder #3 but the 3rd in the firing order correct?
So p0303 is #4, 07 is 7, and 08 is #2 cylinder correct? Car has 4k miles on it 19 GT Premium, I assumed coil packs wouldnt go bad but we did do some swapping around just in case.
Planned to use #5 as a control( plus plug was pristine and is easy to get to hehe), then leakdown whichever P0303 and P0307 cylinders actually are.
Thanks sorry for the Newb question.....Had my car since November put the first 1300k on it getting it home and December just want to drive it and enjoy it a bit before I have some surgeries, no guaranty I'm gonna get my license back after them....
Thanks

Sponsored

 

[ugstang17]

You mention BAP whats the setup? Who tuned it? What fuel are you running (93, E85)? Did problem occur soon after a fill up? need to paint the whole picture if you wish to get good feedback otherwise everytime someone gives a response based on a stock setup there is this "Oh I forgot to mention its not stock...".

 

[Notheryote]

I had some misfires only at startup occasionally and my tuner was saying he’s had some people find out their DI injectors we’re getting stuck in some cases.

 

[BlueCollarDaily]

You mention BAP whats the setup? Who tuned it? What fuel are you running (93, E85)? Did problem occur soon after a fill up? need to paint the whole picture if you wish to get good feedback otherwise everytime someone gives a response based on a stock setup there is this "Oh I forgot to mention its not stock...".

Very valid points.
I'd like to not say whose tune it is....2650TVS rotor pack, full time BAP that comes with kit( on stock pump), Lu47/50lb Bosch, on 93....
The upgrade parts from 10psi to 13psi were installed at same time Lu47s, stock to 103mm tb, 113mm MAF horn, boost a pump and tune.
I did top it off where I always do immediately upon receiving the car from installer at the same shell station which i always use their 93 Vpower ( its 2 miles from my house ). I didnt notice it that evening but I drove it straight home it was literally dark when I picked it up. Next day it started.
So I did just use a gas treatment and filled back up with 93 at a different station. I must state I've used the 93 from that station in this car since day one 98% exclusively AND my 1200hp procharged car as well ( 6 years straight) never however since it was a variable I did top it off with Valero 93 same thing.
One thing I cleaned the MAF today, just wanted to make sure no plastic from new parts or debre got in ect grasping at straws...reinstalled.....kind of went over all the electronics ect. Checked for air leaks behind MAF ect ect...
I then used the SCT BDX ( instead of my MPVI2) to clear the codes and restart and while the behavior was identical touching the MAF seems to have shifted the primary reported misfire to P0308 ( with a 300 and 316 of coarse ).
I also cleared codes and started to the car holding it off idle nearly immediately. And checked codes it never threw the codes till the rpm was below 1100-1000.
A rev off idle is a mess a rev from 2k is clean as can be...

 

[BlueCollarDaily]

I had some misfires only at startup occasionally and my tuner was saying he’s had some people find out their DI injectors we’re getting stuck in some cases.

After the ohm injector coil check I was down for maybe a Lu47 leaking out killing combustion at idle to say 1800rpm where its using the amount of fuel...then swaps over to being able to fire based on air load vs pulsewidth.
I'm just new to this platform and I know there are a zillion variables with cams ect.....
Its something from the lu47s, 103mm, or 113mm MAF horn with accompanying tune...those were the major installs.
Though plugs were changed and gapped back to same, along with coils swapped. That stuff hadn't been touched and it was manufacturer specifies...in terms of plug and tune.....

 

[F1scamp]

Have you done a crank relearn?

 

[ugstang17]

Respect your loyalty to the tuner. What is your vacuum reading at idle? What is the idle RPM? Then note the LTFT's at idle. Normal on stock cams should be about 18-20"Hg and LTFT 1,2 should be 0,0. STFT Will bounce around a little but which is normal. Also note what AFR reads. Should be targeting 14.0 at idle (lambda 1).

Just to cover all bases make sure you are monitoring LTFT1,2 and STFT 1,2 when logging in spite of what the tuner may have you logging. SCT livelink II gives you the ability to make your own datalog config files via a laptop. Or you can monitor all four PID's on your SCT device in gauge mode which may even be easier for diagnostics. LTFT's on a healthy car should never come into play. They shoudl read 0 or 1.0 at all times. They are an indication of a problem if they begin changing as a rule. I am attaching a hyperlink that will give you some basic troubleshooting direction specifically related to LTFT's. It is from the 2011 Coyote Mustang shop manual. So while it is dated it still is valid troubleshooting 411 to do basic diagnosing via LTFT's. I still don't have S440 manuals because I am not certain I am going to keep my 17. Note the bullets on the first page. Depending on your logger using the gauges mode, the STFT's may read zero or 1.0. If they read 1.0 then numbers under 1.0 are negative numbers and numbers over 1.00 are positive. Otherwise if like on the Lund Ngauge gauges display they are 0 then you will see negative or positive numbers.

http://iihs.net/fsm/?d=8&f=Adaptive Fuel DTC Diagnostic Techniques.pdf&p=1

 

[ugstang17]

Have you done a crank relearn?

He has no crank trigger relearn code listed.

 

[BlueCollarDaily]

Have you done a crank relearn?

Yes successful according to the SCT BDX!

 

[BlueCollarDaily]

Respect your loyalty to the tuner. What is your vacuum reading at idle? What is the idle RPM? Then note the LTFT's at idle. Normal on stock cams should be about 18-20"Hg and LTFT 1,2 should be 0,0. STFT Will bounce around a little but which is normal. Also note what AFR reads. Should be targeting 14.0 at idle (lambda 1).

Just to cover all bases make sure you are monitoring LTFT1,2 and STFT 1,2 when logging in spite of what the tuner may have you logging. SCT livelink II gives you the ability to make your own datalog config files via a laptop. Or you can monitor all four PID's on your SCT device in gauge mode which may even be easier for diagnostics. LTFT's on a healthy car should never come into play. They shoudl read 0 or 1.0 at all times. They are an indication of a problem if they begin changing as a rule. I am attaching a hyperlink that will give you some basic troubleshooting direction specifically related to LTFT's. It is from the 2011 Coyote Mustang shop manual. So while it is dated it still is valid troubleshooting 411 to do basic diagnosing via LTFT's. I still don't have S440 manuals because I am not certain I am going to keep my 17. Note the bullets on the first page. Depending on your logger using the gauges mode, the STFT's may read zero or 1.0. If they read 1.0 then numbers under 1.0 are negative numbers and numbers over 1.00 are positive. Otherwise if like on the Lund Ngauge gauges display they are 0 then you will see negative or positive numbers.

http://iihs.net/fsm/?d=8&f=Adaptive Fuel DTC Diagnostic Techniques.pdf&p=1

Thanks for the info....
They seem pretty much like the first stage was STFT within 3% ironically using them or or the LTFT seem to be .78 alternating but that never affected that "stage".
I've been monitoring
STFT, LTFT and bank 1 and 2 commanded and actual....
I will say this just today I noticed a trend where bank 2 during an idle stumble seems to go lean for example then recover rich ( as STFT over shoots ) and back to 14.1-2.....this entire process is 1 second ish....
The LTFT have went negative 3 -4% before they seem to oscillate a little quicker to STFTs trying to attain commanded AFR than I would ASSUME...
I will say this, I can't assert the misfire is real but I can assert the engine runs during these times as if it's real. And clean when its clean.
I just seen another post identical codes and Identical symptoms idle and low speed misfires go away about 3000rpm and WOT...it was like reading a journal...however HIS was the IMRC cracked issue yet mine has identical issues and codes with a TVS...nothing he did resolved it.
So to ME in the case of his issues vs mine and IMRC being cracked or broken either it was leaner or richer in that cylinder than the MAF indicated it should be and caused a misfire.
I also read where misfires can be caused by injector driver failures on PCMs ( been thru this with StandAlones ).
3 big things were changed LU47s, 103tb digital and 113maf horn...with the tune for those changes I would think it would be there......
Also for data on the old stock tb it would idle at .62-.64 lbs/min, same 700ish rpm...now its .92-1.02 going from stock tb and airbox to 103mm tb and 113mm MAF horn...the closer it is to 1.02lbs/min and slightly above the SMOOTHER it runs....so often times you put it in gear and it stumbles hard but once it recovers it actually runs better....
Also a variable is AC on definitely makes it worse way worse...increases load to 23.xx% from 20......
Vacuum starts at 20ish...hot low idle ends up around 15-16". Yes its stock everything 2019 car..supercharger is only "mod"
There are periods when I'm doing a misfire total count using my MPVI2 vs the SCT..where when warmed up it almost stops doing it...especially AC off...and as I did a test drive I could see the "counts" significantly decrease after 1450rpm and by 2700ish all but stop adding....I could literally paddle down to that rpm and it would stop adding misfires...except during decel...

 

[BlueCollarDaily]

He has no crank trigger relearn code listed.

Yea I dont are a p3015 BUT I had read after a new tune you sometimes needs to use the SCT to do crank relearn and KAM resets if the new tune has troubles...desperation move...this is my daily and my health has turned particularly bad as of late which is why I went with my first new car and complete kit...
Everyone I'm having to deal with seems to think it's a race car that can be down months with no sense or urgency to help me get it resolved. So I've taken the knowledge I gleaned from a lifetime with GM in the hobby and my crippled body and done what I can at literal danger to myself...so I find myself here the seemingly LS1tech for Ford owners...such a great resource and I appreciate the responses so far...
I done a lot of reading but keep finding nearly identical symptoms all ending in bad cylinders or the IMRCs so far unfortunately on either end

 

[ugstang17]

Only the IMRC solenoid is still on the car to satisfy the ECU. The IMRC plates themselves are bye-bye with the intake as I understand these 18+ setups. It is not used but must be plugged in according to Edelbrock for the car to run correctly. So if the installer failed to do that this may be part of your problem....? Install steps 24-28 give the details on this.

 

[BlueCollarDaily]

Only the IMRC solenoid is still on the car to satisfy the ECU. The IMRC plates themselves are bye-bye with the intake as I understand these 18+ setups. It is not used but must be plugged in according to Edelbrock for the car to run correctly. So if the installer failed to do that this may be part of your problem....? Install steps 24-28 give the details on this.

I will look at this however it was an operating stage 1 to stage 2 upgrade on my system so those wouldnt have been touched.
Are you inferring their positioning via electrically could be telling the PCM hey were are at idle or tip in enrich XX amount?
I will lean back there and double check the havent come loose maybe knocked loose by injector install cause that is something I havent done....its worth a shot that this point, I'll try the Edelbrock suggestion if those guys say it needs to he plugged in then it does they have a 50 states legal tune!!!

 

[BlueCollarDaily]

Only the IMRC solenoid is still on the car to satisfy the ECU. The IMRC plates themselves are bye-bye with the intake as I understand these 18+ setups. It is not used but must be plugged in according to Edelbrock for the car to run correctly. So if the installer failed to do that this may be part of your problem....? Install steps 24-28 give the details on this.

Its plugged in and zip tied but that was a good guess!!! Thanks for your input on the thread man!
I had hope, I thought maybe they bumped that pulling the rails that was a GOOD GUESS...but it couldnt be that simple...haha
I really do just getting thinking its either gonna be REAL bad or a read duh moment..
All the injectors tested between 12.9-13.1 ohms right in the middle range for Lu47s. I guess I'll get another set just case these are plugged. Once it goes back in the shop for labor I want him to have everything he needs to troubleshoot but really trying to avoid it....
New injectors ohm out and the rails have a fuel pressure sender...good at WOT but not idle...would seem to indicate a blockage in one or a leak that after a certain rpm combustion can occur and the PCM lets the injector fire.
It's got spark via coils and plugs including a new set for no reason....
It's only low cylinder pressure, contaminates ( aka oil) or something in VCT? that would keep it from firing at idle but let it at 3k? Assuming the MAF is reading the correct amount of air with its frequencies correct for that amount of area and measured air volumn, then the tune is providing adequate pulse width to fulfill those measurements for efficient combustion. Should be easy hehe SHOULD be....

 

[ugstang17]

The injectors are good resistance wise, but that doesn't mean you don't have a mechanical issue on several. You could pull the rail on bank one and swap injectors 2 and 3 and see if the problem follows the injector to cylinder two (P0302) or stays on cylinder 3 (P0303). That would at least be a lead in to question the injectors...or at least 3,7,8 FI's.

You can pull the relay to the fuel pump and start the car and let it idle until it dies to relieve rail pressure and minimize fuel in the rail before pulling them and swapping the two.

VCT would generate other codes associated accordingly. Failed VCT's you would know...assuming these fail similar to how the 4.6 3V phaser failed on my 2005.

You do have good vacuum correct? 18-20"Hg at idle?

Sponsored