Thoughts on a Miss fire

[whitmanink]

Hey guys .
Got my engine back together and started today .
It idled fine . And after letting it sit and idle for ten minutes and then shutting it off .
Started it again , let it idle about 5 minutes..
Shut it off ,
Then about an hour later I started it up and too it out and it runs fun untill I give it about 60% throttle. Then it starts missing or stumble..
Pretty much the exact same thing I had before I pulled and put a new head on. ..
It feels like it's the driver side .. no cel codes ..
That side has new plugs and. Coil packs..

Just wanna pick some minds and see what you guys come up with.

Thanks and cheers

 

[Blue03Cobra]

Heat/Temperature related?

 

[StockishS197]

For a misfire CEL to trigger, it has to happen enough during a 1000 revolutions, so it could be misfiring and not trigger.

I would log misfires by Cyl and see if you see any smoking gun, at least to see which side or cylinder is effected.

 

[whitmanink]

so today i

For a misfire CEL to trigger, it has to happen enough during a 1000 revolutions, so it could be misfiring and not trigger.

I would log misfires by Cyl and see if you see any smoking gun, at least to see which side or cylinder is effected

today i was able to go out and do some things.. first i swapped fuel injector rails and the fps, also put new orings in fuel rail and injectors,

cleaned the maf,
cleaned the plug for the crank sensor ,,
pulled all the spark plugs to look at them,,,(all seem good)
put the original cop packs on,,

sprayed maf cleaner around intake to see if its leaking..

i still get stumble\misfires after half throttle,,,
it wont do it in natural,, but in gear it will stumble,,

i ordered a compression tester and it will be here tonight..
i tryed to use my sct to data log but i couldnt find a part that said misfires or cylinders,,
only battery ,, idle and rpm and one other thing but i forget..

do i need to hook up the laptop to the sct like with lito to see the misfires and cylinders ?

im really scratching my head on this one..

 

[StockishS197]

Yes, you need to use SCT LiveLink and find the PID for misfires by cylinder to log them. The SCT device won’t have them by default.

 

[Juice]

Forscan > livelink

 

[GlassTop09]

+1 for Forscan........

Provided a Forscan Mode 6 Self-Check Component data file (the entire IM Readiness & Mode 6 data post check file info from PCM.....) off my car in converted .txt format so any Windows text reader (NotePad, WordPad, etc...) can open & read it thus you don't need to have Forscan to read these after initial capture & save as from Forscan into Windows........shows all cyl misfire data as a group & across individual cyls..........includes 1/4 mi WOT hits & shifts.
Only reason why EVAP didn't complete during this single drive cycle (following a tune reflash......) was due to fuel tank level being > 85%..............EVAP monitor will only run between fuel tank level > 15% but < 85%.

Just a snippet of the capabilities of Forscan...............

 

[whitmanink]

yea ill be getting a dongle from amazon to get and use forscan .
i have a thinkdag2 but obviously fords wil be so much more better and in depth for my car ..

funny one for you guys,,
ordered a compression tester from amazon, \
got it Thursday ,, (find out it didnt have 12mm but the 16mm..
the 16mm wouldn't thread at all.,.,

so i returned it ,, found one with the 12mm and the 16mm one,,
the 16mm one worked great .. cylinders 1-4 all at 160 ,163,161 163..

went over to the driver side and the threads wont catch lol..
so i got another one coming today and hopefully both work well..

my goal is to check the driver side compression.. if all checks out,
when forscan arrives , start checking each cylinder for misfires,,
or maybe a funky maf sensor ?

something tells me its electrical ,, but thats just a hunch ,, hopefully,time will tell

 

[whitmanink]

On another note... Yesterday when I was hooking up the laptop to the sct in my car.. I noticed that my interior lights would flicker every now and again.....

 

[whitmanink]

I got another compression tester and the 12mm won't thread in , so I'm confused on that one ...

But none the less.
I took my car out and wanted to try to throw a code so I drove it for about 3 miles .

It idles fine but after about %27 throttle it backfires and misfires ..

The thinkdag said no knock detected on any cylinder so idk .

I drove around and logged these inputs ..
For those advanced guys ,

Is it normal for the throttle position to be at %14 when my foot is off the pedal? .

I don't know maf readings but I had that up as well .. anyone who might be able to decipher this ,id greatly appreciate it

 

[GlassTop09]

I got another compression tester and the 12mm won't thread in , so I'm confused on that one ...

This adapter is the 1 you need...............

https://www.amazon.com/OTC-5608-Adapter-Compression-Tester/dp/B00F5YZNZ8/ref=sr_1_1?dib=eyJ2IjoiMSJ9.p_J7dnrclZTFfuWm8_NvQ6w5YOKb3VnTuBiiH9m2iDiV6bpLvI9rFoGDOz6ZxoQW5aBnjgda6-q-ia4Y8_XX85cQVCJ6sdJV_5TgrnXyn6w78yKYC6ubmk6JFHCWWdrjFlCzcpvlgiMy3bIUogWDjarg8mQIBBKYqhzOXERyFq51aFgjW4as_clx5_BXwTQ41GRx5XNtw65U26mLf-A3tiBFHYZzoF6Z7RmL4iw0Itsqk2jqTfnhtyCuq60fAGNSyHb9BrOwQNAIVeaOnxhEJsaMePTvVA3bQu5wYEkgSmw.FPhCqkMvpCOYpxn7uDEsc0NE1PFKdW0sHhJgjwbrQ6o&dib_tag=se&keywords=otc+12mm+adapter&qid=1779130733&s=automotive&sr=1-1

The large end is std M14 thread so it will work w\ most all compression testers & leakdown testers. The 1 I bought & use...........
Ain't cheap but will work.
If you shop around, you can find cheaper versions but make sure that it is the 5608 design...........

Hope this helps.

 

[whitmanink]

I also noted that when I came home and let it idle for a minute, the maf readings were always changing ,, I dunno if they are supposed to or not , again I'm not wiz with any of the electronics or the readings

 

[whitmanink]

This adapter is the 1 you need...............

https://www.amazon.com/OTC-5608-Adapter-Compression-Tester/dp/B00F5YZNZ8/ref=sr_1_1?dib=eyJ2IjoiMSJ9.p_J7dnrclZTFfuWm8_NvQ6w5YOKb3VnTuBiiH9m2iDiV6bpLvI9rFoGDOz6ZxoQW5aBnjgda6-q-ia4Y8_XX85cQVCJ6sdJV_5TgrnXyn6w78yKYC6ubmk6JFHCWWdrjFlCzcpvlgiMy3bIUogWDjarg8mQIBBKYqhzOXERyFq51aFgjW4as_clx5_BXwTQ41GRx5XNtw65U26mLf-A3tiBFHYZzoF6Z7RmL4iw0Itsqk2jqTfnhtyCuq60fAGNSyHb9BrOwQNAIVeaOnxhEJsaMePTvVA3bQu5wYEkgSmw.FPhCqkMvpCOYpxn7uDEsc0NE1PFKdW0sHhJgjwbrQ6o&dib_tag=se&keywords=otc+12mm+adapter&qid=1779130733&s=automotive&sr=1-1

The large end is std M14 thread so it will work w\ most all compression testers & leakdown testers. The 1 I bought & use...........
Ain't cheap but will work.
If you shop around, you can find cheaper versions but make sure that it is the 5608 design...........

Hope this helps.

Well now that makes. Sence now .. thank you for not making me think I'm loosing my mind with this lol..
I was wondering if I needed a specific one for the 12mm

 

[cavero]

Regarding the 14% at idle, the throttle has to be open even a little bit at idle. I haven't had my car for the last month so can't go out and check, but pulling up a data log I did back in April, my throttle pos readings were roughly 12% at idle after the car was fully warmed up. I have the GT500 TB and a centri blower, so the 12% I was seeing vs 14% you have, probably not something to worry about.

I logged a bunch of stuff using the Torque app on my phone and a OBDII bluetooth adapter (OBDLink MX), so not sure if Forscan calls these PIDs the same thing or not, but here's what I had:

[FORD]Accelerator Pedal Position(%)	[FORD]Throttle Position (Actual)(°)	[FORD]Throttle Position (Desired)(°)	Accelerator PedalPosition D(%)	Accelerator PedalPosition E(%)	Accelerator PedalPosition F(%)
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​

 

[whitmanink]

Regarding the 14% at idle, the throttle has to be open even a little bit at idle. I haven't had my car for the last month so can't go out and check, but pulling up a data log I did back in April, my throttle pos readings were roughly 12% at idle after the car was fully warmed up. I have the GT500 TB and a centri blower, so the 12% I was seeing vs 14% you have, probably not something to worry about.

I logged a bunch of stuff using the Torque app on my phone and a OBDII bluetooth adapter (OBDLink MX), so not sure if Forscan calls these PIDs the same thing or not, but here's what I had:

[FORD]Accelerator Pedal Position(%)	[FORD]Throttle Position (Actual)(°)	[FORD]Throttle Position (Desired)(°)	Accelerator PedalPosition D(%)	Accelerator PedalPosition E(%)	Accelerator PedalPosition F(%)
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​
0​	12.10938​	11.38916​	18.03922​	28.23529​	17.2549​

Well I greatly appreciate yore response..
Now I know it's in range ..

I'm not sure what the mag is supposed to look like ..
I'm waiting for the compression fitting to come so I can test the compression on the drivers side.. altho I think thats good I'll check just to be sure..

I am using my thinkdag2 to log stuff for now.

I'm gonna get and try the forscan see if that helps any.

 

[whitmanink]

Ok also looking at fuel trim 1 and 2 .. it's getting. Different numbers sometimes .. others they are the same?

Not sure if that's saying anything or normal?

 

[StockishS197]

STFTs/LTFTs changing is normal and expected. If your trims are +/- 5% bank to bank, that’s not the issue.

 

[whitmanink]

STFTs/LTFTs changing is normal and expected. If your trims are +/- 5% bank to bank, that’s not the issue.

Ok that's one less thing down.. again excuse my ignorance as I am not well versed on the engine electrical part..

I just find it odd that no misfires are being detected...
I still think it's a sensor or electrical...

I still need to do compression on the driver's side once the tool comes and try forscan once that comes..

But I just dont understand how nothing is coming up at all ..

I even drove it to the gym today ( slow slow slow lol) but still couldn't get a light or a pending code.

 

[Kev555]

Possibly something to do with the cylinder or cylinders when no sensors are picking it up? It will be interesting to see what your compression test Whitmanink but hopefully all is ok there. It still could be something electrical. Forscan I thought was good for picking up cylinder misses. Mine had a slight miss on one cylinder way back as I could feel it just about while driving but no codes or lights showed up. Forscan live data picked it up. it was a coil that wasnt performing as it should.

 

[Juice]

It must set code(s) if its misfiring. Unless misfire detection had been tuned out.
BTW, is Miss Fire cute?