[ironman]

Hello to everyone.
I contact you all in desperation. I have an i30 diesel PD 6spd manual 2019 that i have owned since new. 86,000km always serviced by Hyundai.
It has been to the service dept for this annoying and dangerous hesitation / stuttering condition at least 6 times without any resolution.
Its had all sorts of fuel treatments through the fuel system, fuel filters changed out etc. No fault codes in the ECU.

It starts and drives fine most of the time. Cold start, hot start whatever. But seemingly randomly it will hesitate on acceleration as if on a petrol engine, it misfires or the plugs break down. It will do this on cruise control going up a gradual incline in top gear or exiting a roundabout in 2nd and into 3rd gear.
Some days it will do this 3 or 4 times in a single drive, other times it behaves itself for days.

Im buggered if I know and seemingly the guys at Hyundai also.

Anyone know anything about this condition?

Oh, and the dealer has tried cleaning the MAP sensor over and over too with no change.

Thanks to everyone for your help in advance.

[CraigB]

Annoying these types of issues can be when service has no idea

I was thinking leads but that would be more noticeable at high rpm's and shouldn't happen on a 2 year old car, sticky injectors or blocked fuel filter could be a possibility though

[Greyhound]

Has it happened since you last filled with fuel?
I'm thinking maybe contaminated or water in fuel, but that's me just thinking out loud.

[Lakes]

Sound's like fuel starvation.
A diesel motor has full bore of air & controls engine speed via fuel. So any limitations is from lack of fuel. Go to a Diesel Specialist. good luck.

[ironman]

we suspect it got a load of poor diesel early on. Hasn't been right since.

Thought of trying a diesel bug treatment. Maybe it has the fungus in the fuel system?

What makes it night on impossible to fix is how random it does it.
Like working with animals on television, it never plays up when you want it to, like showing the tech what it does.
Makes me look like a fool.

Anyone have any success stories using a diesel fuel treatment?

[Pnut]

Not with diesel but as mentioned above i have also seen a petrol tank with a lot of water in it cause stuttering issues, best treatment in that case was to run the tank down and then empty all the gas, water and contaminants out. Then make sure it was filled at newer stations with better equipment.