Sometimes when pulling hard in 4th car starts stuttering

>sometimes when pulling hard in 4th car starts stuttering
>stuttering feels like hitting the rev limit, power comes and power goes in a fraction of a second repeatedly like you're putting your foot on the throttle on and off
>no CEL
>only does it in 4th, maybe because it has more load?
The car is due for plugs anyway, but it kinda sounds like coils, right?

The car idles fine and pulls fine when that shit doesn't happen.
What might be the issue?

Fueling. Also check o2 sensors.

Now that it's dark out, put the hood up and spritz your plug wires with water.

If you see little climbing lightning along them then they're shit and you need new plug wires. Coils will sometimes spark as well if they're shit.

You reckon its injectors?

Eh, getting water into the coil cables doesn’t sound that good of an idea, but I get your point. But I don’t think I’ll risk frying anything if one of the cables is fucked.

>Eh, getting water into the coil cables doesn’t sound that good of an idea
Water gets in you engine bay every time it rains. You drive one fucking POS if it dies when it rains. It's about testing the parts that might be failing when they get wet.

Same problem changed fuel filter and fixed it
>pic related it’s the stock filter from fucking 2001 the gas that came out was blacker than my oil

I had that problem once. They said it looked like mud :(

Hm, it sounds like it's only happening in 4th gear, and it's stuttering. I would try asking Veeky Forums for help.

Car is relatively new, and the fuel filter is not serviceable.

Did this shit always when it was sunny and dry, so humidity has nothing to do with it.

How is it not serviceable? It's a wear item and all you need to do is look at the fuel lines coming in to your engine bay to find the fuel filter.

Do it when it's dark and cold so the condensation comes out of the air. I didn't tell you to spray your wires when it's dry and in the middle of the day with the sun beating down on you.

this is the fiat guy right?

mine ended up being plugs and leads

It’s a lifetime filter built into the pump. My mind is boggled too, but it really isn’t serviceable.

kek, you misunderstood me breh, I said the car always did the stuttering when it was sunny and dry.

Not that fiat guy, but I do have a Fiat with a multiair. Did you have the same issue?

The pump has like a sock and that's not permanent. Maybe you really are running fuel sludge through your engine no wonder the sparks have a hard time lighting it.

Might be, but there’s literally no replacement filters in the market.
The pump and filter are sold as one.

my mom's car did that, turns out it needed new spark plugs

>Help. I can't fuel my vehicle because it takes too long!!!!!!!

>You reckon its injectors?

Maybe. Seems like it only happens under the biggest loads, right? That would be when the most fuel is being (or trying to be) put into the engine. A place like O'Reilly auto should have a rental fuel pressure tester you can use to rule out a fuel pump. Make sure to test it at the high load you're having the problem at. Injectors are easy enough to pull out and test/clean just to do it anyway, as is fuel filter and sometimes pressure regulator. Cel usually doesnt recognise fuel system problems unless theyre emissions related or bad enough to cause sustained misfires, in which case it will just set generec misfire codes.
Spark generation isn't engine load dependent, load alters the curve but has no role in the actual electrical generation of the spark, assuming of course that you haven't confused high load with high rpm while having an alternator problem. *usually* when it's either a case of a mechanical failure or a solid state/low tech electrical part faulure, it's the mech. Moving wear vs non moving wear.
One other I could think of is a plug is oriented in a way that the spark is blown out by incoming a/f mix. May try to shorten the gap by .010 and see if that fixes it. If going this route look at indexing your plugs.
I'm assuming it's in your engine and not your trans.
What is it and have you done anything to it?

my car is the same. filter and pump are one.

The stuttering does show up at about in-between 4,000~5000rpm.
I do think the car is also way too recent to be having pump issues.

>I do think the car is also way too recent to be having pump issues.
You might be surprised.

I had a weird issue once that I couldn't figure out that was similar and it turned out to be a shitty chinese fuel filter that the PO put in. The filter media would pack and seal itself when you tried to flow too much through it and it sounded like fuel starvation. Probably not it though.

Hook up scan tool analyse fuel trims replicate the problem

I had something that sounds like what you're describing not too long ago. Took it in for warranty and was told it was a bad coil pack.

It's an american 500 abarth if that matters

Any further diagnostics? You can try changing the plugs and wires around to see if the misfire code changes cylinders or not. I if it does, then you have a bad wire, plug, or possibly coil if you were clever enough to re-rig the coils.

Otherwise maybe it's time to ask yourself how much a new coil pack costs compared to throwing money at a different part. It's pretty easy to make sure you have the basics sorted out when it comes to the ignition system. You could be looking at a bad fueling situation that just happens to affect cylinder 4 before the others.