1.4TSI Cold start hesitant acceleration

[ow3njade]

Hello!

I have a problem with my Scirocco, 1.4TSI 160 bhp CAVD. When the engine is cold, and I start to drive, there is some intermittent hesitation under acceleration between 2000-3000 rpm. This lasts for about 10-20 seconds, after that the engine runs fine. It happened that I would get an error logged ( Cylinder misfire + multiple misfire ) I've changed the spark plugs, the coils, but the problem is still there ( No errors logged this time ). I just want your opinion before I go back to the mechanic.

Thank you all!

[blower]

Perform a compression test, to rule out any piston issues.

If you haven't done so already it maybe worth running some in tank injector cleaner through as the issue could be fueling related (clogged injectors).

In terms of spark plugs, what part number was put in?, also what year of manufacture is your car?

[ow3njade]

2009. As spark plugs I can tell you that they're original VW, I have no idea the part number. I will do the compression test and respond to this thread. Thank you!

[blower]

The compression test should be between 150-200psi on all 4 cylinders, with a reasonable balance, say within 10psi of each other.

If that comes back fine then I would suspect a fuelling issue - injector problems or fuel pressure issues, if the mechanic has access to VCDS then I'd log the fuel rail pressure on a drive, and look what's happening right when it's hesitating. Also log boost pressure, just to make sure there are no issues with the supercharger at the lower RPM's, but I would expect other error codes to have been logged if there were boost issues.

[TheRustySheriff]

Carbon build up in manifold? What sort of milage has the car done?

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[blower]

Carbon build up in manifold? What sort of milage has the car done?

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Could well be this - its no where near as common on the 1.4 tsi as the 2.0 tsi - but yes if the misfires are only from cold and never happen again once warmed up, then could be carbon build up.

Only issue is cleaning the valves and intake on this engine is difficult, 3-4 hours just to get to the intake ports and then the only way to clean it is with a media blaster due to the ports being very deep and hard to access as the intake is on the rear of the engine.

[TheRustySheriff]

I know. £400 quid and 5 hours later, i have a sparkley inlet manifold and valves. Check my previous posts for pictures.

That coupled with a full service and my 97k mile car runs like new!!

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