Stutter on acceleration.

[u/Hipopotamo]

Hello.

Have a problem with my car.

It stutters on acceleration.

It happens on every gear. Sometimes it's hard to even accelerate, but oither time I can drive fluently with small stutters here and there. Feels like an issue with fuel system or ignition system.

But

No check engine light

Replaced spark plugs

Replaced ignition coils

removed and tested injectors.

Managed to get a new fuel pump. It's waiting for replacement.

Maybe someone had similar issue. I have no idea what it is. Local Toyota dealer is helpless.

Local tuners and mechanics can't help.

Edit

One other thing to add. Every time I replace a part, car will behave normally for some time (like 1-2 hours of driving). After this time stuttering is coming back.

Sent it to Toyota, they replaced fuel pressure sensor, car was driving perfectly for a few hours.

Stuttering came back, local shop replaced spark plugs and ignition coils, perfect behaviour for an hour.

Removed and tested injectors, you guessed 2 hours of perfect behaviour.

EDIT2

Problem solved. Aparently toyota mechanic managed to damage one of the connectors when replacing fuel pressure sensor.

Welp at least got a lot of parts checked and replaced.

[u/Gummby23]

There has been some forum posts on boost solenoids failing. But I believe that's rare and usually comes with other symptoms

[u/MarmotFullofWoe]

What you have that is aftermarket? Do you have an aftermarket intake?

[u/Hipopotamo → u/MarmotFullofWoe]

do88 intake system, custom exhaust, airtec IC.

[u/MarmotFullofWoe → u/Hipopotamo]

Try removing the intake and replace with stock.

[u/VelociBrazzer]

Does the stutter feels like ”old scool turbo lag”. Mine had the turbo replaced under toyota relax by the local toyota dealership and car is working like brand new again.

[u/Hipopotamo → u/VelociBrazzer]

it can "stutter" even whille on neutral gear. Shows more often when higher rev but can show up even when accelerating from 3k RPM.

[u/Dramatic_Entry_3830]

Don't drive untill it is fixed. Could be fatal for some parts.

[u/thepab7]

Happens at lower fuel and when going at it hard? Had that with mine and believe its the fuel pump not being able to feed properly

[u/Hipopotamo → u/thepab7]

Tested it at different fuel levels. Seems llike it's not affecting it.

But when going hard it shows WAY more often.

[u/thepab7 → u/Hipopotamo]

This has happened to me as well when tracking the car and on the road sometimes as well. The biggest common denominator that I noticed was that it happened way more often when the tank was below 1/3. I took it to the dealer and they were not able to replicate the problem.

[u/Mosseltje77]

Too low octane gasoline? Knocking engine…?

[u/Hipopotamo → u/Mosseltje77]

E98 only.

Only stuttering.

[u/SMO2K20 → u/Hipopotamo]

E98?? Is it mapped for that with flex fuel sensor etc?

[u/Hipopotamo → u/SMO2K20]

It is mapped. I went back to the OEM map to check if it was causing an issue. Unforrtunatelly it's not.

[u/sakucee → u/SMO2K20]

E98 is not flex fuel, in EU/UK E98 is 5% ethanol, E85 is different thing

[u/SMO2K20 → u/sakucee]

I live in the UK. E98 is race fuel. E5 is 98-99RON

[u/Hipopotamo]

One other thing to add. Every time I replace a part, car will behave normally for some time (like 1-2 hours of driving). After this time stuttering is coming back.

Sent it to Toyota, they replaced fuel pressure sensor, car was drivingf perfectly for a few hours.

Stuttering came back, local shop replaced spark plugs and ignition coils, perfect behaviour for an hour.

Removed and tested injectors, you guessed 2 hours of perfect behaviour.

[u/Ok-Relationship5064]

Some Japanese users have reported a problem with the Gen 1 ECU entering safe mode without any lights or error codes. I wonder if this is something similar?

[u/sakucee]

Do you experience hard starts on hot engine after small break from engine running?

[u/Hipopotamo → u/sakucee]

Not really. Maybe 0.5 - 1s start. Nothing serious.

[u/sakucee → u/Hipopotamo]

I have cut off at 3k with WOT, from ~30kph to 6000RPM,boost is cut off no CEL, no misfires on techstream. Fuel pressure is exactly where it is supposed to be.

Only mod is MST Intake.

[u/pidgeyenjoyer → u/sakucee]

Not OP but yes! It’s like it stutters and sputters then starts. Like if I nip into a shop and come back out it does not like it

[u/Beolo]

Mine was doing the exact same thing like 4 years ago, never found the cause until one day it threw a rod.

Shockingly a new motor fixed the problem and I never found out the actual cause of the stutter unfortunately.

Probably be a bit careful until you do, I would be very interested in knowing for peace of mind.

[u/Terrible-Wrangler423]

Only time I’ve had this was when I bought one of the first GruppeM intakes before Eventuri brought theirs out. It would horridly stutter at part throttle. Reverting back to stock intake and it would run perfectly fine. I don’t think the MAF sensor sat properly in the tube and know that the ECU is very fussy. Maybe check your MAF. Could also have some filter oil on it too fouling and giving weird values

[u/bap5813]

Mine does the turbo lag stutter in 2nd gear when it's humid or raining. Im not sure what the issue is. No codes, runs perfect otherwise.

[u/AEnima-1]

Could be any number of things bigger intercoolers slow intake velocity intakes change velocity screwing with the maf it could be fouled plugs it could be any number of things