Hesitation on Acceleration (60k km/ 5 years) | FIXED: cleaned fuel system

[dgiarazza]

Hello guys, this month i noticed my car have an issue with acceleration. When accelerating from 0kmh-40kmh, it feel a bit hesitated, like something is holding back the cvt not to shift yet. And from 40kmh-60mkh (60kmh is my normal cruising speed since i live in small city), the car is struggling to reach the 60kmh mark, kind of lagging and pause at 50kmh. Not unless i floor a bit of gas, then it will get to 60kmh-65kmh. The engine also sounds a bit rough on idle than usual, just a bit tho, not crazy rough.

Year:2015 Mirage G4 (5th years)
Mileage: 60,000km
Recent service at 50k km: Engine oil, oil filter, cvt oil, cvt cartridge filter, coolant, air filter (all in correct level)

Im a light footed type. Very seldom cruising at 2k rpm and above. Mostly i limit my rpm at 1.5k rpm/60kmh. But now i need to push abit at 1.7k rpm to maintain 60kmh, make the engine struggle a bit and sounds rough, which bother me. I did checked for dtc on my elm327, but no code.

Thing that i have done recently is cleaning the tb and the map sensor. Its dirty. After the cleaning, the car behave overpower a bit, myb because of coolant air pocket symptom when i removed the tb. But now after 1 week, the car back to its old problem. My next guess is either one of those: {spark plug, coil pack, dirty injector, dirty fuel filter, weak fuel pump}.

I just ordered a set of denso iridium power spark plug. Any recommendation, or if u guys ever experience my problem pls feel free to share or advise. Thanks!

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This was solved by cleaning out the fuel system:

Hye, update:
Car has restored its performance after i cleaned the clogged fuel strainer, its dark and dirty. sprayed with some carb cleaner and managed to make it turn white again.

i also did injector cleaning. i did purchased the fuel filter assy tho, but mybe not going change it this time, perhaps next 80k km.

it's not that hard to pull out the fuel pump/filter assy. i use hammer and flat screwdriver.but its very hard to install it back to the fuel tank. i recommend u guys who'd like to diy this stuff to purchase the fuel filter wrench socket, it'll make thing way easier.

dont forget to depressurized the fuel before pulling the fuel hose. (pull the fuel pump connector socket and start the car, let it run and shut off by itself, turn off the ignition,pull the battery negative, and release additonal pressure by lossen the fuel tank cap.)

goodluck friends.

[Eggman]

Have you tried using a fuel system cleaner?

[dgiarazza]

I am using techron fuel system cleaner at the moment, have been 4 days, minor improvement. But my car still have the hesitation symptoms.

[inuvik]

Im a light footed type. Very seldom cruising at 2k rpm and above. Mostly i limit my rpm at 1.5k rpm/60kmh. But now i need to push abit at 1.7k rpm to maintain 60kmh, make the engine struggle a bit and sounds rough, which bother me. I did checked for dtc on my elm327, but no code.

How about the old "Italian Tune-up?".

[dgiarazza]

What was the last thing you did before this started happening?
How are you checking cvt fluid level?
How does the color of the fluid look?
Do you have a way to see tps voltage or percentage?
Gotta ask this one, do you have a low tire?
Is it more noticeable in cold weather?

I find in my car if I drive like an old lady all the time then try to pass someone it's a bit of a turd but if drive it more aggressively it adapts and becomes slightly less of a turd. That might all be in my head though.

There is 1 day i reverse-parked right against a wall(about an inch gap), yes im using aftermarket muffler. Then the next morning, i start the car, it started but died in 3 sec. then i realized could be my exhaust was blocked. i put to N and moved the car away from the wall, try cranking it again, a bit of struggle and weak but managed to run normally. within 1 week from that occurence, i noticed my car become unresponsive.

i checked the cvt fluid on a levelled ground, the mark on the dipstick is spot on. plus i just change the fluid last 6 months. color of the fluid is brownish/golden.

tps voltage? i have no idea, i have elm327 tho. myb i'll check on it later.

my tire is at the correct pressure(32psi) on 195/50/15.(have been 2yrs). cold or hot day, it doesnt affect the symptom, its still there,regardless.

I drive like an old lady tho, lol. but i seldom change my driving style unless if got morning rush to work, but again, very seldom.

[dgiarazza]

last 2 days after i got techron in the tank, i did floored it up to 90-100kmh (2.5-3k rpm), but not aggressively tho, bcos worry of other thing might broken/damaged. yes im broke atm and need to be careful on my monthly expenses. anyway i found out at 2.5k rpm, my car can maintain at 100kmh before, but this time, at 2.5k rpm, the speed only clock at 90ish kmh.

[dgiarazza]

Hye, update:
Car has restored its performance after i cleaned the clogged fuel strainer, its dark and dirty. sprayed with some carb cleaner and managed to make it turn white again.

i also did injector cleaning. i did purchased the fuel filter assy tho, but mybe not going change it this time, perhaps next 80k km.

it's not that hard to pull out the fuel pump/filter assy. i use hammer and flat screwdriver.but its very hard to install it back to the fuel tank. i recommend u guys who'd like to diy this stuff to purchase the fuel filter wrench socket, it'll make thing way easier.

dont forget to depressurized the fuel before pulling the fuel hose. (pull the fuel pump connector socket and start the car, let it run and shut off by itself, turn off the ignition,pull the battery negative, and release additonal pressure by lossen the fuel tank cap.)

goodluck friends.

[Eggman]

Hye, update:
Car has restored its performance after i cleaned the clogged fuel strainer, its dark and dirty. sprayed with some carb cleaner and managed to make it turn white again.

i also did injector cleaning. i did purchased the fuel filter assy tho, but mybe not going change it this time, perhaps next 80k km.

it's not that hard to pull out the fuel pump/filter assy. i use hammer and flat screwdriver.but its very hard to install it back to the fuel tank. i recommend u guys who'd like to diy this stuff to purchase the fuel filter wrench socket, it'll make thing way easier.

dont forget to depressurized the fuel before pulling the fuel hose. (pull the fuel pump connector socket and start the car, let it run and shut off by itself, turn off the ignition,pull the battery negative, and release additonal pressure by lossen the fuel tank cap.)

goodluck friends.

Thanks for sharing your results. We'll use this to update your first post with the fix.

Just to clarify, when you say fuel strainer, you are referring to the one in the fuel tank, right? If that was clogged, wouldn't that also affect high-speed driving by choking off the fuel supply? Sounds like fouled fuel injectors were more likely the cause, but since both were done at the same time it's hard to tell which was the culprit.

[dgiarazza]

Yes the one in the tank. The fuel strainer is the one that at the bottom of the fuel pump assembly. While the fuel filter is the one that surround the fuel pump. (Sorry, but that's how i interpret the items, my u guys have different lingo)

Yeah. Im also not sure which one actually the cause. But the most obvious cause from my perspective is the fuel strainer.

[Eggman]

Yeah. Im also not sure which one actually the cause. But the most obvious cause from my perspective is the fuel strainer.

Maybe it’s due to a steady diet of bad fuel?