The Broken Fiat Club

One of the biggest problems that has plagued the Fiat community seems to be top end misfires and breakup. Some cars never experience this, but others do.

There are different types of breakups/misfires/cutouts that people experience.

What these have in common is that they are ALL in the upper RPM range (approximately 5000-5500 RPM, occasionally up to redline). P0300 code may or may not be present. If you're consistently getting P0301, P0302, P0303 or P0304 then there's likely a different issue such as a bad plug, bad multiair, bad valve or bad injector.

1) Light hesitation around 5000-5500 RPM. Power curve drops but vehicle balance not upset.

2) Hard cutout / hiccups. Car seems to simply HICCUP really fast and then keep going. Jerks vehicle hard. Does this 2 or 3 times in a pull at WOT.

3) Hard breakup. Car starts to sputter and will keep doing it until you let off the gas, does this at WOT on a pull.

4) Hard breakup AFTER shifting at redline. Car will sputter and act like it's flooded until you let off the gas in the next gear, then pulls fine.

Various solutions/answers are offered for these problems, but usually what happens is that people spend thousands of dollars chasing the issue and often it is never resolved, or seems to go away on its own.

Solutions / Causes offered:

1) Bad coils, you need to upgrade to 4C coils. This typically resolves type #1 of misfire/breakup but not the others. People have had mixed luck with swapping coils.

2) Bad plugs, you need new plugs, and you need to gap them at 0.024. Again, mixed results, and tends to only solve type #1 of misfire/breakup.

3) Boost leak. Many people have spent the cost of a new intercooler only to find that boost leaks were not the cause of their breakups either. Again, a drop in power at the upper RPM might be a boost leak, but chances are it's not causing type #2, #3, #4 of breakups. Usually a boost leak will result only in lost boost and power, not breaking up.

4) Clogged PCV system. A bad/clogged PCV system may cause issues, typically the type #1 of misfire and breakup.

5) Fuel mixture issues. This seems to help with Type #3 or #4 of breakups, but requires providing datalogs to the tuner and a modified tune.

6) Bad tune. Several people having these problems have gone through the expensive of switching tuners from one to another. Again, this has mixed results. I've heard of it resolving issues, but I've also heard of issues remaining.

The primary type of cutout that several people I've talked to are unable to resolve is type #2. Hard jerk-like cutouts that just jolt the car and cause it to suddenly lose boost.

If anyone is experiencing or has experienced any of these types of cutouts/breakups/hesitations in the UPPER RPM RANGE at WOT (not at idle or low RPM or part-throttle), then post your experiences in this thread.

Include:
1. Details of your mods and tune when you experienced the problem.
2. Did you datalog? What did you find out?
3. What did NOT solve the problem.
4. What DID solve the problem for YOU (if solved)
5. Are you still experiencing the problem?

1. V4.1 Intake, GFB DV+, Turbosmart Wastegate, Forge Blow off plate, NGEN Coil Packs, NGK Iridium plugs gapped by EC running phase 0/1 Pops n bangs 2015 Automatic Abarth.
2. I do not currently have a set up for datalogging. I only experience the issue on phase 1, phase 0 has no issue.
3. Spark plugs, wastegate, coilpacks and cleaning PCV system have not fixed the problem.
4. N/A
5. Yes, My breakup is as early as 4200 which is different than most peoples experiences that I have read. Sometimes the car will pull through the breakup on its own, other times I have to let off the gas and get back on it. It is not a constant problem it just randomly appears, when it happens I take note if I was pushing the car hard or not. I get it on Acceleration but the main culprit is shifting. It really likes to present itself during a WOT shift.

6. Extra Info: I recently pulled my spark plugs to replace them, this is the 4th time I have replaced the plugs on this car. This last time I noticed that the plug closest to the PCV box had its threads soaked in oil. I cleared out the spark plug tube as best as I could and hoped for the best. I did not have the issue after cleaning my spark plugs/changing them..about 3 months later, maybe 3k miles the problem has appeared again. I am going to pull them again this weekend and check out how they look. My assumption is a bad spark plug tube seal..I have not problem tackling this problem on my own, but the only company I can find that sells a full kit for the seal replacement with a valve cover gasket is a company I'd rather not risk buying anything from.

wafflewizard wrote: ↑Thu Feb 14, 2019 4:24 pm 1. V4.1 Intake, GFB DV+, Turbosmart Wastegate, Forge Blow off plate, NGEN Coil Packs, NGK Iridium plugs gapped by EC running phase 0/1 Pops n bangs 2015 Automatic Abarth.
2. I do not currently have a set up for datalogging. I only experience the issue on phase 1, phase 0 has no issue.
3. Spark plugs, wastegate, coilpacks and cleaning PCV system have not fixed the problem.
4. N/A
5. Yes, My breakup is as early as 4200 which is different than most peoples experiences that I have read. Sometimes the car will pull through the breakup on its own, other times I have to let off the gas and get back on it. It is not a constant problem it just randomly appears, when it happens I take note if I was pushing the car hard or not. I get it on Acceleration but the main culprit is shifting. It really likes to present itself during a WOT shift.

6. Extra Info: I recently pulled my spark plugs to replace them, this is the 4th time I have replaced the plugs on this car. This last time I noticed that the plug closest to the PCV box had its threads soaked in oil. I cleared out the spark plug tube as best as I could and hoped for the best. I did not have the issue after cleaning my spark plugs/changing them..about 3 months later, maybe 3k miles the problem has appeared again. I am going to pull them again this weekend and check out how they look. My assumption is a bad spark plug tube seal..I have not problem tackling this problem on my own, but the only company I can find that sells a full kit for the seal replacement with a valve cover gasket is a company I'd rather not risk buying anything from.

How would you describe the breakup? Is it individual hard jerks, or is it more of a "rumble/stumble" where it gets rough and loses power?

For my own response, I have 2 Fiats and 2 Experiences.

2015 500 Abarth M/T
1. I experienced breakups at shift point and in the beginning of the next gear. This happened BOTH with piggybacks AND with Eurodrive tune.
2. Yes, I did datalog. I discovered that the fuel mixture was going very rich at around redline, and it was STAYING rich after the shift. Like 9.5:1 rich.
3. Coils (even IP Plasma coils), FMIC, plugs, none of that solved the issue.
4. The issue was solved when I provided detailed datalogs to Toby at EC and we identified that the ECU was causing a fuel-flood condition at WOT and at shift. He found a table in the stock 2015 ECU file that had some errant values and was able to correct these, the problem went away completely.
5. Not experiencing the issue now, it's solved.

2015 500 Turbo Auto
1. Phase 1 EC, 4C coils, Injen Intake
2. Have not extensively datalogged yet.
3. Coils did not solve. Cleaning/Replacing PCV did not solve.
4. Not yet solved.
5. Yes, still experiencing the issue. The issue I'm having on the 500T is completely different from the 500 Abarth issue. It is cutting out with a hard jerk under WOT, 2 or 3 times in a row sometimes. Fine at 3/4 throttle. Doesn't seem to affect shift point. More like WOT *GASP* WOT ... if that makes sense.

MadFiat wrote: ↑Thu Feb 14, 2019 4:37 pm

wafflewizard wrote: ↑Thu Feb 14, 2019 4:24 pm 1. V4.1 Intake, GFB DV+, Turbosmart Wastegate, Forge Blow off plate, NGEN Coil Packs, NGK Iridium plugs gapped by EC running phase 0/1 Pops n bangs 2015 Automatic Abarth.
2. I do not currently have a set up for datalogging. I only experience the issue on phase 1, phase 0 has no issue.
3. Spark plugs, wastegate, coilpacks and cleaning PCV system have not fixed the problem.
4. N/A
5. Yes, My breakup is as early as 4200 which is different than most peoples experiences that I have read. Sometimes the car will pull through the breakup on its own, other times I have to let off the gas and get back on it. It is not a constant problem it just randomly appears, when it happens I take note if I was pushing the car hard or not. I get it on Acceleration but the main culprit is shifting. It really likes to present itself during a WOT shift.

6. Extra Info: I recently pulled my spark plugs to replace them, this is the 4th time I have replaced the plugs on this car. This last time I noticed that the plug closest to the PCV box had its threads soaked in oil. I cleared out the spark plug tube as best as I could and hoped for the best. I did not have the issue after cleaning my spark plugs/changing them..about 3 months later, maybe 3k miles the problem has appeared again. I am going to pull them again this weekend and check out how they look. My assumption is a bad spark plug tube seal..I have not problem tackling this problem on my own, but the only company I can find that sells a full kit for the seal replacement with a valve cover gasket is a company I'd rather not risk buying anything from.

How would you describe the breakup? Is it individual hard jerks, or is it more of a "rumble/stumble" where it gets rough and loses power?

I would say its the rumble stutter. When I experience the issue its after a shift and car feels like im hitting a rev limiter and wont gain any power..Its very audible in the car too, it sounds like a fart...Forgive me for the lack of better term. It almost sounds like an audi waiting on launch control, that even stutter pattern; I will link a video with pretty much the same sound im experiencing after a shift.
https://youtu.be/_TKWT45_RLk?t=55

wafflewizard wrote: ↑Thu Feb 14, 2019 5:03 pm

MadFiat wrote: ↑Thu Feb 14, 2019 4:37 pm

wafflewizard wrote: ↑Thu Feb 14, 2019 4:24 pm 1. V4.1 Intake, GFB DV+, Turbosmart Wastegate, Forge Blow off plate, NGEN Coil Packs, NGK Iridium plugs gapped by EC running phase 0/1 Pops n bangs 2015 Automatic Abarth.
2. I do not currently have a set up for datalogging. I only experience the issue on phase 1, phase 0 has no issue.
3. Spark plugs, wastegate, coilpacks and cleaning PCV system have not fixed the problem.
4. N/A
5. Yes, My breakup is as early as 4200 which is different than most peoples experiences that I have read. Sometimes the car will pull through the breakup on its own, other times I have to let off the gas and get back on it. It is not a constant problem it just randomly appears, when it happens I take note if I was pushing the car hard or not. I get it on Acceleration but the main culprit is shifting. It really likes to present itself during a WOT shift.

6. Extra Info: I recently pulled my spark plugs to replace them, this is the 4th time I have replaced the plugs on this car. This last time I noticed that the plug closest to the PCV box had its threads soaked in oil. I cleared out the spark plug tube as best as I could and hoped for the best. I did not have the issue after cleaning my spark plugs/changing them..about 3 months later, maybe 3k miles the problem has appeared again. I am going to pull them again this weekend and check out how they look. My assumption is a bad spark plug tube seal..I have not problem tackling this problem on my own, but the only company I can find that sells a full kit for the seal replacement with a valve cover gasket is a company I'd rather not risk buying anything from.

How would you describe the breakup? Is it individual hard jerks, or is it more of a "rumble/stumble" where it gets rough and loses power?

I would say its the rumble stutter. When I experience the issue its after a shift and car feels like im hitting a rev limiter and wont gain any power..Its very audible in the car too, it sounds like a fart...Forgive me for the lack of better term. It almost sounds like an audi waiting on launch control, that even stutter pattern; I will link a video with pretty much the same sound im experiencing after a shift.
https://youtu.be/_TKWT45_RLk?t=55

That's what my Abarth would do if I shifted at WOT, it would gurgle in the next gear and not gain power until I let off the gas for a couple of seconds, and then it would be able to go. That turned out to be a bad value in the fuel table that Toby was able to fix. Odd thing was it would do it even with stock tune and a piggyback, so I know the issue was present on the stock tune.

I would recommend you log AFR measured ratio when it is doing that. Keep your foot in it, and I'll be you see the AFR is way too rich at that point. That indicates a tune issue that should be able to be corrected.

MadFiat wrote: ↑Thu Feb 14, 2019 5:09 pm

wafflewizard wrote: ↑Thu Feb 14, 2019 5:03 pm

MadFiat wrote: ↑Thu Feb 14, 2019 4:37 pm

How would you describe the breakup? Is it individual hard jerks, or is it more of a "rumble/stumble" where it gets rough and loses power?

I would say its the rumble stutter. When I experience the issue its after a shift and car feels like im hitting a rev limiter and wont gain any power..Its very audible in the car too, it sounds like a fart...Forgive me for the lack of better term. It almost sounds like an audi waiting on launch control, that even stutter pattern; I will link a video with pretty much the same sound im experiencing after a shift.
https://youtu.be/_TKWT45_RLk?t=55

That's what my Abarth would do if I shifted at WOT, it would gurgle in the next gear and not gain power until I let off the gas for a couple of seconds, and then it would be able to go. That turned out to be a bad value in the fuel table that Toby was able to fix. Odd thing was it would do it even with stock tune and a piggyback, so I know the issue was present on the stock tune.

I would recommend you log AFR measured ratio when it is doing that. Keep your foot in it, and I'll be you see the AFR is way too rich at that point. That indicates a tune issue that should be able to be corrected.

I was curious when you mentioned in your post that you had a 2015 and that it had a tuning issue. What tools would you recommend to log with? I am brand new to data logging with cars, but im pretty tech savy and would like to get into it some more before I go with a big turbo upgrade down the line. And sooner would be better than later with Datalogging so I can try to solve my issue!
Did you get poor gas mileage when you had this problem? It may just be my driving habits, but I get around 180-200 miles before I get a fill up light.

wafflewizard wrote: ↑Thu Feb 14, 2019 5:15 pm

MadFiat wrote: ↑Thu Feb 14, 2019 5:09 pm

wafflewizard wrote: ↑Thu Feb 14, 2019 5:03 pm

I would say its the rumble stutter. When I experience the issue its after a shift and car feels like im hitting a rev limiter and wont gain any power..Its very audible in the car too, it sounds like a fart...Forgive me for the lack of better term. It almost sounds like an audi waiting on launch control, that even stutter pattern; I will link a video with pretty much the same sound im experiencing after a shift.
https://youtu.be/_TKWT45_RLk?t=55

That's what my Abarth would do if I shifted at WOT, it would gurgle in the next gear and not gain power until I let off the gas for a couple of seconds, and then it would be able to go. That turned out to be a bad value in the fuel table that Toby was able to fix. Odd thing was it would do it even with stock tune and a piggyback, so I know the issue was present on the stock tune.

I would recommend you log AFR measured ratio when it is doing that. Keep your foot in it, and I'll be you see the AFR is way too rich at that point. That indicates a tune issue that should be able to be corrected.

I was curious when you mentioned in your post that you had a 2015 and that it had a tuning issue. What tools would you recommend to log with? I am brand new to data logging with cars, but im pretty tech savy and would like to get into it some more before I go with a big turbo upgrade down the line. And sooner would be better than later with Datalogging so I can try to solve my issue!
Did you get poor gas mileage when you had this problem? It may just be my driving habits, but I get around 180-200 miles before I get a fill up light.

I used an OBDLink LX. Cheaper Chinese knock-offs will work but have a slower update rate, so can log less detail. More samples per second is better so you can really see what's going on.

After that, I simply used Torque Pro with the Fiat ADV plugin, on Android to log with. It will log a CSV file with whatever parameters you want.

As far as fuel economy, I've always gotten terrible, that pretty much has to do with my driving style.

Great thread.

When I first went to the J&J/RAW tune (in 2015) I would get severe breakup at around 5000 rpm at WOT. That was cured by upgrading the coils to NGEN coils (which have stayed the course to date). That was a hard stumble with no CELs.

After the head work was done, with the upgraded C&B cam, I had a persistent P0300 code but that came without any kind of noticeable misfire or hesitation.. Over the last 18 months or so I've been trying to find the cause. It happened with any EC tune or stock tune; driving hard or driving gently. Over the period I took off the light weight drive pulley, I replaced the O2 sensors as they were throwing codes, chased down electrical issues because my battery kept dying and my lights worked strangely. Finally I swapped the PCV and cleaned the AOS and that made a difference. The code still appeared but it was less frequent. Last month I did an oil change and primed the multi-air with oil (long story). The code has now gone completely. I also upgraded to a FX250 clutch and lwfw at the same time, so perhaps it's related to that as well.

Currently the car is running really well, it has a slight blip around 5,000rpm. Not even a misfire really, it's like the engine just forgot to fire on one revolution and then it's off again. No CELs. I'm going to do some data logging next month to see if I can see anything odd, I have some long drives to Dallas and San Antonio to wind the car out a bit.

I think the most common issue is the “blip” at 5000-5500. It seems to be the issue with almost all of us.