Hello All,

 

I have been searching the forums with my problems and tried most remedies and now a bit stuck. Pretty much the car was all fine, and I accidently knocked off couple of vaccum pipes, but re-connected them straight away. Anyway I started to get underboost problems, so i replaced a couple of the vaccum pipes which stopped that, but but now I get over boost.

 

The problem I cannot understand... The car drives perfect and is really quick ( Remapped 2 years ago) but as soon as you cruise at about 70MPH you get limp mode, over boost code. I can drive it hard in 2nd etc and it is fine. Guaranteed limp mode every time.  

 

Here is the code

 

17965 - Charge Pressure Control 

            P1557 - 35-00 - Positive Deviation

 

I am at the point now, where I can only think to try the Mr Muscle, but this i am not 100% will fix it as the car drives perfect in low gears, even if you drive it really hard.

 

I have attached graph from vagcom of actual boost v  delivered boost. Hope someone can make more sense of it than i can, as when i logged the data it does not tell me which is actual boost and which is delivered boost!!.

Edited 13 December, 20169 yr by cyber_killer

Not a diesel expert myself, but this may give some info on the code until a more knowledgeable bod comes along - http://wiki.ross-tech.com/wiki/index.php/17965/P1557/005463

As a rough idea if Mr Muscle will be of much use, try moving the turbo actuators control rod in (I'd use a small bar or something rather than thumb) and see if it's smooth and returns back to it's normal position etc. If it's very stiff, gritty and or squeaky in it's movement I would go ahead and give it a try and the worse you find it the more time and attention I'd give to carrying it out thoroughly as per the guides, if EGR valve still fitted, a good time to clean it out too. 

Mine felt fine bar the same limp mode issue and fault code (limp mode gone upon restarting engine every time), always did it under similar circumstances under more gradual / continual increasing load in 4th or 5th. When I did Mr Muscle I was shocked at how crap the car had slowly become over time and it felt like it had just regained 20bhp after. 

Edited 13 December, 20169 yr by FUBAR

Thanks I will try that I will get the good old car from my jack on it ... I should have mentioned.

 

This is the ASV 110 BHP ( remapped) with EGR blank. About 18 months ago i fitted a second hand turbo to it... I did not clean the turbo out or anything prior to fitting ( which I did) as the original turbo went with such a bang/smoke etc i thought the car was dead. I did however clean all the inlet/inter-cooler etc out.

 

 

 

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if it was fine 'till you upset the pipes I'd say you have a leak a tiny one is enough to give trouble

That is my thinking but I cannot find a leak :( is there any particular way i can test these pipes? or is there a particular 1 which would cause these symptoms?  I am starting to think the 2 which I have replaced ( Using eBay piping) may be the cause... I have put cable ties on either end of them to make sure they are on secure. Apart from the 1 which runs to the EGR valve as there is not enough room to put a cable tie on it.

well I guess a mini vac pump (forgot the name)   would be a good start   long shot-- it's not the vac kinking the pipe???   whilst bore is not important -wall thickness is

I tested the vac pump with vagcom and it seems to be doing its job all ok. I have now cleaned it out with Mr Muscle, only taken for a small drive and all seems ok :) 

 

Hopefully it has sorted the problem.