Running Like a Pig

[batso]

HI Guys

I'm after some advice on my Mk5 Golf, 2.0L TDi.


Start up is a bit on the laggy side, takes a few turns to kick in, runs fine at idle, as well as when you give it the berries.

The problem is that at low throttle openings, it hesitates, almost stalls.

To date, i've rebuilt the tandem pump, replaced the MAF sensor and replaced the EGR valve. But the problem seems to be getting worse.

I'm thinking (hoping) that all ive done is missed plugging in a vacuum hose or something.

Any thoughts?

[h100vw]

No fault light? Boost leaks are a favourite. SPlit pipes etc

[batso]

Scans are clear.

Hmm, yeah, better recheck the boost pipes as well, thanks for the prompt.

Sent from my Redmi Note 8 Pro using Tapatalk

[batso]

So far, I've tried:

Replace maf sensor
Replace egr valve
Rebuilt the tandem pump
Swapped around the fuel temp sensor and coolant temp sensor
Rewired the fuel temp sensor
Smoke tested the boost pipes
Smoke tested all the vacuum pipes I can find

The thing still hates low speed/low revs. It stumbles and pig roots at around 1200rpm, otherwise runs fine.

Some days are worse than others, gets worse when hot.

What am I missing???

Sent from my Redmi Note 8 Pro using Tapatalk

[TristanJ]

So might be a red herring but when was your timing belt done? I was having trouble starting mine, three weeks later the belt went which of course destroyed the engine and I had to fit a new one.


Sent from my iPhone using Tapatalk

[batso]

Only about 80k on the current timing belt.

Was wondering if its the turbo actuator getting a little sticky...

Sent from my Redmi Note 8 Pro using Tapatalk

[epidemic]

Hey are you still having an issue?
Have you changed the fuel filter recently? If not, change it immediately and pour a diesel injector cleaner directly into the fuel filter canister.
What about the ASV? This could be caked up with carbon and causing issues. I would also get the timing checked as well.