2018+ whippled scat packs issues

[white1]

I have a customer with a 2018 scatpack with a 426 and a whipple. Came to me from another shop due to going into a sort of limp mode after the third pull. Not exactly a limp mode but almost a reduced power mode.
During logs will show misfires on cylinder 8
Changed plugs, coil pack, and found a stuck injector.
New injectors, and problem comes back.

I am currently having the same issue with a 2019 scat pack with a 426 and MMX max effort cam I'm tuning for a shop remotely.
Dyno tune went wonderfully, during the street tuning, we are getting a CEL for P0308 (misfire cyl 8) and after two pulls, on the third pull it too goes into a reduced power mode of sorts

The same shop had another 2018/2019 car with a whipple that had cyl 8 misfire problems as well, but that tuner was able to turn the misfire detection up, and disable P0308 and had no more issues


Does anyone have any ideas what could be causing this?
cal files for both vehicles
log is from the 2019

2018 scat 426 whipple.hpt
2019 scat 426 mmx me whipple.hpt

misfiringbuzzkillLOG008.hpl

[PurpleRam]

I don’t know, and I’m only guessing here, do a continuity test n the injector connector, I had an odd ball mystery with my 14 ram when I 1st put the 431 stroker in it, mine was # 6, it would go days without an issue,then it would toss a miss fire code, changed a bunch of stuff , the 1st time, 2nd time it did it , it was a “bad injector, 2 more times it was the injector again. Then on of the McLaren guys we were working with suggested the wiring was an issue...... check it and didn’t find a thing, following week same fing thing, that time I did find # 6 had more resistance then the the rest

[Hemituna]

Had a guy with similar issue on whipple tuned 2020 Scat pack with 3.0L that i helped tune out the surging/flutter.

He also had the misfire/code issue but he apparently cured it as follows:

"FYI, I went ahead and nearly maxed the Net Positive Torque table under the misfire tab, and now that misfire problem is gone. Crazy since I couldn?t find anything on that table anywhere, but it is what Whipple recommended."


I've personally never had to change that table before but he was using Whipples tune and thats what they recommended and seems to have worked.

[white1]

Had a guy with similar issue on whippled 2020 Scat pack that i helped tune out the surging/flutter.

He had the misfire/code issue also but he apparently cured it as follows:

"FYI, I went ahead and nearly maxed the Net Positive Torque table under the misfire tab, and now that misfire problem is gone. Crazy since I couldn?t find anything on that table anywhere, but it is what Whipple recommended."


I've personally never had to change that table before but he was using Whipples tune and thats what they recommended and seems to have worked.

Thanks a bunch. I ended up doing something similar and it seemed to work. Ill try it this way on the local car and see if that works for him.

[coanan]

Thanks a bunch. I ended up doing something similar and it seemed to work. Ill try it this way on the local car and see if that works for him.

Thought I was the only one with the #8 random going dead/misfire.

Where is the fix??

[white1]

Thought I was the only one with the #8 random going dead/misfire.

Where is the fix??

Had to disable the misfire detection

[coanan]

Had to disable the misfire detection

Thanks

[Nofun]

Can you give me a screen shot of that table? I am just wondering what the numbers look like, thanks

[rays04gtx]

Had to disable the misfire detection

With all due respect , that's the band aide and not the cure..... We've had four 2018/19s this year alone, 3 boosted 1 NA ,6 last year all boosted , three 18's a 19 and a pair of 2020's ,we've rebuilt 2 of the 18s that leaned out and burned up # 8, I know the tuner of one of them FLYs by here every now and again....and will not return the owners calls or Email messages.
it's wiring issue, and the OEM harnesses are hit and miss. it was (is) same deal with 2014/15 V6s and the mysterious cylinder# 3 Miss fire.

[Fsingh]

I'm having the same problem. I have gen 5 installed on my 2018 scat pack. Cylinder is 8 is misfiring. Whipple is not able to resolve the issue. Its been 7 months whipple tried to fix the issue but no luck
Whipple emailed me another tune yesterday. After installting the newer tune all cylinders started misfiring.
Is there any fix for this issue?

[white1]

With all due respect , that's the band aide and not the cure..... We've had four 2018/19s this year alone, 3 boosted 1 NA ,6 last year all boosted , three 18's a 19 and a pair of 2020's ,we've rebuilt 2 of the 18s that leaned out and burned up # 8, I know the tuner of one of them FLYs by here every now and again....and will not return the owners calls or Email messages.
it's wiring issue, and the OEM harnesses are hit and miss. it was (is) same deal with 2014/15 V6s and the mysterious cylinder# 3 Miss fire.

I figured it was a band-aid. Its hard to wrap my head around the issues only being on 2018+, only vehicles with whipples, and all showing only a cyl 8 misfire.

I wonder why whipple suggest raising the net positive torque table (which seemed to work on another vehicle with the same issue) if the issue is actually mechanical. Especially seeing the others on this thread with the same issue. All experiencing cyl 8 misfire. Im no means arguing the "band-aid" fix, just curious why its only cylinder 8, only on 2018+ vehicles and only with whiples

[rays04gtx]

I figured it was a band-aid. Its hard to wrap my head around the issues only being on 2018+, only vehicles with whipples, and all showing only a cyl 8 misfire.

I wonder why whipple suggest raising the net positive torque table (which seemed to work on another vehicle with the same issue) if the issue is actually mechanical. Especially seeing the others on this thread with the same issue. All experiencing cyl 8 misfire. Im no means arguing the "band-aid" fix, just curious why its only cylinder 8, only on 2018+ vehicles and only with whiples

We had one NA do it, and it's a big G3 over 468CI,close to 980HP replaced the engine harness and no more issue.

Why #8 I have my theory...
1st car(2018 Charger) we replaced the harness on and that one has been misfire free for 2 years now, mild tune with a 2.9L
2nd car also in 2020(2018 Challenger) not so lucky, all in all it's on it's 3rd Harness but has been issue free for over a year now.......the last time I talked to the owner, again Mild tune 2.9L
3rd one(2018 Challenger) was when I said Whoa lets look in to this, we placed EGT sensors on the headers found # 8 was running around 200F higher then the other 7 , measured the coil packs their wiring, the injector wiring with a inferred thermometer, and # 8 injector wiring was running hotter then the other 7. I called up the owner of the 1st car we got lucky on , we measured his car and found #8 was higher the the others but not as bad as the car we were guininy(sp) pigging on......now in trying to keep it Apples to Apples, we detuned this car to match "car#1's tune only difference between the two was the Whipple, Car #1 has a 2.9L and car# 3 had a 3.3L but during testing both cars 1-7 averaged with in 50*F while #8 there was 75-100*f difference in Header temps and wiring temps were 5-10F higher.
So then I thought it was something going on with the Whipple, some how it was leaning out #8 and the injector was working over time to maintain VE/AFR and pulling more current then the other 7 which would explain the hotter wiring........I wanted to build a harness for the car, Owner didn't like it, said it made no sense and was going to someone else to tune it.......car left, "pro tuner "fixed it" .....Now we have the car back and are building a new Engine for it....Leaned out #8 and melted the piston, and Pro tuner will not return his calls, hot tune with a 3.3L

the 3 Ken Bell topped 392s my kid has done we didn't see this issue at all and I haven't heard of any Hellcats with #8 issues...lots of other issues but not #8 going all psycho ....so at that point I was thinking it's got to be the Whipple, then we had the NA car do it.....it was fine for the 1st 6 or 7 dyno pulls, but then it started tossing code, changed the harness and All good, all 8 running with in reasonable temps of each other.


we replaced the harness on 3 more and have had "success" interesting to note that the ones we have been lucky with are 2.9L with mild 6-10lbs boost.

Over the summer my kids shop did a 3.3l Whipple topped 411 for a 2017 Challenger, no #8 issues, the 3.3l came off of "car#3" and it's fine on the 2017 with the same tune as what was ran on the 2018.....

I still think the Hotter you make the Whipple tune the more prevalent it is(talking 2018/2019) but why 2018/19 and not any other year........sooooo

I talked to my other son (Ben) he's the one that worked for DCX/FCA as a Programmer , he shrugs his shoulder and says it's deep in the program, just take what you can get.

But Why Whipple(s) what are they doing different , I can't answer that, but what ever it is it's triggering something to make #8 draw more current then the others and that is triggering some Emissions protocol in the program.

My theory on the harness , (and it's a band aide also) , is that the wiring gets weak from excessive draw and it's like a over stressed breaker just gets worse with usage, and the injector starts running less duty cycle then the others which causes a lean condition and triggers a misfire.




Two Replies up I said it's a wiring issue, the more I look into this and think about it , my views change.......but I'm not going to edit or change the other post.

[coanan]

Mines a 2013.

#8 cuts out randomly after a hard run. Eng misses for a while and then clears up, like something is overheating causing it to cut out, then cools and cylinder starts firing again.

Odd random issue.

I've swapped inj, plugs, and coils around, same issue, #8.

[Fsingh]

After installing the whipple i was getting cylinder 8 misfiring and knock retard at wot. Whipple wasn't able to fix the issue. Whipple recommended to drive like this KR retard wont damage the motor and ecm will put the timing back. As per whipple something was wrong with my motor
But it was a tune issue. I found a Tuner in Europe. He fixed all issues in first revision . I see big difference in hp and the way it drives now.

[dodgeboy]

I have this issue on my 5.7l with 2.9l Whipple. Goes good for a while then I read the codes and have P0308 pending. I need a tuner in the states, preferably Ohio. My original tuner ghosted me

[LilSick]

you need a internet mechanic Frank

: )

[dodgeboy]

you need a internet mechanic Frank

: )

Not going to swap engine harnesses over the web... Just wish I knew what I did to piss off my Tuner/Builder. I'll try to get ahold of whipple and see about the Torque table thingy.

[LilSick]

my car does it sometimes but i am never logging when it does

its always after i load a tune at the track without the laptop fully charged - and i dont hear it miss until i am almost all the way home (after driving 30 mins)

with your money i would call fuel tech and ditch this dodge junk : )

[dodgeboy]

my car does it sometimes but i am never logging when it does

its always after i load a tune at the track without the laptop fully charged - and i dont hear it miss until i am almost all the way home (after driving 30 mins)

with your money i would call fuel tech and ditch this dodge junk : )

I'll just wait until next year and get an electric one that will fly!

[dangrebel]

bump, have a customers Whippled 5.7 2013 charger dropping out #8 injector after a hard run intermittently. we"ve swapped injector, checked harness, changed coil pack, everything under the sun.