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Author Topic: Scirocco CR140 TDI fuel pressure fluctuating/poor idle.  (Read 582 times)

Offline GVK

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Scirocco CR140 TDI fuel pressure fluctuating/poor idle.
« on: January 10, 2024, 01:16:25 am »
Hi guys, as title Scirocco CR140 fuel pressure fluctuating on live data jumping from 200-400bar at idle.

Had a fuel pressure regulation fault code which I deleted and didn't save (schoolboy error!) but regardless of that the engine is running rough , especially when cold, it surges on accel. for the 1st couple of miles or so in a journey. Even when hot the idle is 'stumbly'.

I'm dreading it needs a HPFP as they are about a grand UKP, but I did some Googling at found it could be the fuel pressure regulator thats fitted to one end of the common rail. Darkside developments sell these for £175.

I've got no means of doing a leak off check on the injectors.

Of course the more I Google the more I see doom and gloom of pump failure, swarf blocking up the injectors etc.

Anyone else had a similar issure and what was the cure?

Offline pudding

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Re: Scirocco CR140 TDI fuel pressure fluctuating/poor idle.
« Reply #1 on: January 12, 2024, 03:20:07 pm »
Yeah HPFP was my first thought as well but you could try the regulator first.  Happens on BMWs as well, and other fairly modern TDIs using that Bosch pump. 

Apparently sh1t fuel contributes to the problem because of poor lubrication and/or water in it.  You been using Asda's finest in it?  :grin: 



2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline GVK

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Re: Scirocco CR140 TDI fuel pressure fluctuating/poor idle.
« Reply #2 on: March 09, 2024, 04:18:33 pm »
Fixed by the fuel pressure regulator that is in the end of the common rail 057 130 764 H - Got a Bosch part from Darkside developments for £174, apparently over £300 from VW!

We were able to fit it without removing the common rail need a 30mm and 32mm open ended spanner to fit, had to remove the wiring loom from injectors and glo-plugs etc and remove a couple of clamps on top of the inlet.