[k.kxlay]

Hi All!

List of engine mods:

• Alfa 4C Coil Packs (Plugs changed ~3k miles ago)
• EC FMIC
• AFe CAI
• Forge BoV
• 2½" Cat Back Straight Pipe Exhaust (Dual Tip)
• Turbo Blanket
• Oil Catch Can
• EC Phase 2 Burbles

Been having issues with the 1.4L Multiair having an "arrythmia" after pushing the car hard. Upon startup, the car idles super smoothly and after normal driving as well. No rod knocking sounds or weird sounds. RPMs will blip after spirited driving or maybe when the oil is too hot? I'm in Vegas, so the summers are pretty unforgiving temperature wise. I checked for any leaks but I simply cannot find any. I even cleaned out my intake filter (which helped smooth the RPMs and bring back more power tbh haha). I've been having these "arrythmia" problems for a long time and I'm on my 2nd motor. Issue occured with both motors (original and current one swapped from a 2k mile donor). Had zero issues for the first few months of the engine swap and I always change oil at ~3k miles with full synthetic 5W-40. Zero codes (atm) but have had previous codes of: P1CEA, P1300, and P1302. Average MPG is around ~24MPG even with mild driving. Thinking the car is running rich?

Video Example

 

[BavarianGuy]

First of all:

Upon startup, the car idles super smoothly and after normal driving as well. No rod knocking sounds or weird sounds. RPMs will blip after spirited driving or maybe when the oil is too hot?

If everything is fine, whats the problem then? Or i ask another way: what exactly is the problem?

If you had those problems on your second motor then what was NOT changed out? The build-in Turbo has some faults thats know to cause issues (Wastegate getting worn out/flapping, the wastegate solenoid can wear out prematurely and dont actuate correctly).

Here are your fault-codes where you can check it up:

Fiat Punto P1300 Engine Trouble Code - Fiat Punto P1300 OBD-II Diagnostic Powertrain (P) Trouble Code For Fiat Punto | EngineTroubleCode.com

Fiat Punto P1300 OBD-II Diagnostic Powertrain (P) Trouble Code Information Page. Reason for Fiat Punto P1300 and find the solution for the code Fiat Punto P1300 , we'll give to how to fix Fiat Punto P1300 trouble code problem.

p1300.enginetroublecode.com

P1CEA: Code Meaning, Causes, Symptoms, & Tech Notes

The Evaporative Purge Monitor tests the integrity of the hoses/tube between the throttle body/intake and the fuel tank. At key off, the Powertrain Control

www.engine-codes.com

OBDII diagnostics. Trouble code definition for code P1302. Causes of error P1302

OBDII/EOBD diagnostic code definition. More than 18000 codes for all autos. Trouble code definition for code P1302

obdii.pro

So, you had:

-Cylinder 2 misfiring (Either a bad injector, bad coil or not enough compression)
-You have a problem with your fuel tank (either you have a 2019-model, where the fuelpump can be faulty from factory or it doesnt purge your gases inside the fuel-tank correctly, making the fuel-air-ratio incorrect).
-And a throttle/pedal position sensor had a problem.

So i dont know if those codes are still present from your post, but for your information.

The 24 MPG is a bit too much, but i dont know what your driving-behavioure is: if you are like me and dont drive it like a baby then yeah, thats correct. If you drive it "normally" then you are over the normal consumption.

And from what i see on your mod-list is the Phase 2 Burbles, so let me ask: Was the tune done with all Mods installed previously or was it something added after? Because as far as i can see it you have modified the exhaust, fuel and air-components, so if your tune does not compensate for all those differences your problem lies there.

At best you check for yourself the above question and if you have done the tune before installing other mods bring it to a tuner and let it get recalibrated/adjusted so it compensates for the mods.

Otherwise i give this thread to the community, cant help much out.

 

[BavarianGuy]

And for your interest, here is a video for the P1300 for rough idle, where he shows you the position of the 2 camshaft-position-sensors on a abarth 500, which has the same motor as the 124 spider. Might look into if there is a problem with those 2. As i said: i dont know what was NOT changed out for your second motor.

 

[sharkcohen]

You may have a bad cam.

 

[BavarianGuy]

Yeah, but as he wrote, he has a new engine. Which is why it would be good to know what exactly was replaced from the first to second engine.

 

[k.kxlay]

Only thing that was replaced was the whole engine block. All wiring harnesses were re-used. Coilpacks were bought after the new motor was installed.

Tbh, after some digging around online as well as doing basic tuneup work:

• Oil change
• Intake Filter cleanup and tubing cleanup
• Fuel injectors cleaned

My MPGs have been a steady 25mpg or so now even with the Vegas heat soak and semi-spirited driving. On regular trips I even see it avg around 30mpg.

What I did differently and found online is the whole charcoal canister being a culprit of having EVAP purge issues if it gets soaked. I've always pumped a "bit extra" just to make the price even out lol But have since stopped after reading online about what a charcoal canister does and why you shouldn't pump further.

I still get the arrythmia from time to time, but it's not as bad anymore nor as frequent. Also stopped using the burbles tune.

Could be right about the tune not compensating for the exhaust work as it's basically a 2.5" custom exhaust with no muffler / resonator (Classica trim comes with both). I haven't had any re-occurring CEL / codes for a solid 3-4 months now (thankfully). I will say, the engine still has a "cold" start idle around 900RPM and doesn't really drop unless I drive - this is after the initial higher RPM range and when it stabilizes. I did of course go to those websites about the codes and everywhere else I could to read up on them, but I don't even know where our MAF sensor is tbh lol

 

[BavarianGuy]

Do you have any tools where you can read out your sensors? If you tune an engine, you basically just say to the engine how much fuel/air is getting into the cylinder by opening/closing the valves longer or shorter. Depending on your map you can read out how much negative/positive ignition-timing is being done on the controller part. It tells you how much the system is trying to find the best setting for minimizing engine-knock. Now if its a a arrythmia, so i think its smth like a tuckern or unrhythmic exhaust-note, it can be that the ECU has a pretty good negative ignition-timing on 1-2 cylinders. If those cylinders are the ones with the shortes path on the exhaust-manifold, then its most likely an issue with the custom exhaust.

Now, based on your post, "the whole engine block" means the camshaft, rods ect. are all switched out. So i dont think it has to do something with it.

So i really think if you have a custom exhaust with no muffler, the back-pressure of your exhaust is not being compensated correctly, leading to (i assume a decrease in resistance) a incorrect air/fuel mixture on the exhaust-manifold. So the mixture, because of easier escaping through the exhaust-valve, which normally should be compensated in the tune to shorter opening-times, is incorrect, which is why the system tries to mitigate that by going into negative ignition-timing.

But the best thing would be to take your car to a tuner that can read out the values and make a statement to you.

And yeah, overfilling the gas-tank is a good way to destroy the system, worst case is the gases inside the tank are overpressurizing and they WILL find a way out.

The only other thing i could think of would be that through overfilling you have a leakage/defect in the EVAP-system, basically your motor wants to purge the gases inside the fuel-tank and the system corespondingly injects less fuel and more gases into the engine, but because somethings amiss you have too much air and too less fuel. But its guesswork atm.

 

[k.kxlay]

I apologize for anything I may mis-speak about haha. I'm not too mechanically savvy, but I can kinda get around 🙏

The motor was from a donor vehicle with 2.5k miles clocked in on it and purchased through Red Line Auto. When the swap was complete, it drove as if it was brand new and the burbles were amazing 👀 Now the burbles kinda don't sound as great, but the engine is smooth as can be - aside from the random arrythmias after spirited driving.

Would you be able to recommend to me the tool you are mentioning? Or is it a datalogging tool that I can send to a tuner, for example Eurocompulsion?

 

[rglass]

You need a Bluetooth OBD reader, and your camshaft is likely going. This has been a growing development that we’re trying to learn more about and understand. Several folks have been dealing with this including myself.

 

[alltimesaresoon]

You might be interested in joining the discord......