slowing down turbo diesel

[randolph57]

Have a problem with a power reduction-my turbo diesel seems to be normally aspirated! This is intermittent as it drove for around 10 miles as it normally does(adequate acceleration/top speed)However after a down hill run with the throttle off there is minimal power and really unexciting things happen when a incline comes into the equation.
As i have yet to crawl under the van would I be correct in assuming there is a fault with the blow off valve or associated pipework? Having done a search some people advocate the 'doing away' repair as these valves are ****!
basically there is minimal power above 2500 rpm no smoke no extra oil consumption and all seems to remain normal.
What are the main recommendations with respect to this valve?

Thanks in advance

[Syncro G]

My blow off valve isn't set right and opens frequently on high power use like acceleration of hills at speed. Makes a very loud hiss noise when it does it and power obvesously drops off. Tends to cycle on and off but can be constant. If there is a pipe fitted to the valve it might mask the sound so try removing the pipe and open the passengers window and you'll hear it if it opens, a boost guage will show it up too. I keep meaning to ajust mine but till I'm happy with the oil temp monitering and fit a boost guage I'm not that bothered. One thing I've noticed, if you can't use full throttle fuel economy is fantastic!

[randolph57]

Solved the problem Fuel starvation being the cause! I had a lot of air in the supply line to the fuel pump air getting in from the Fuel filter/heater from hell Despite changing all clips the expensive(genuine vw) fuel return preheater union and seal it was still so bad that top speed was around 50 on the flat and 15 on any incline.
Strangely no 'kangarooing' just no power-previously i had checked operation of the Lda at 12 psi and was praying my turbo was ok
Have now put a temporary inline filter in place and a loop betweennormal inlet/outlet connections and have all power back
Am still reluctant to revert to standard filter with so many potential failure points so intend to fit a earlier version with a straight in and out arrangement and send the fuel return straight back to the tank.

[ringo]

Am still reluctant to revert to standard filter with so many potential failure points so intend to fit a earlier version with a straight in and out arrangement and send the fuel return straight back to the tank.

This is quite a common upgrade - and one that i did after i experienced really annoying air leaks in the system causing me to have to crank the engine for ages.....

I've not noticed any side effects from not having the return line heat up the filter, but thats not saying much..

Ringo

[Hoss]

Hello, could anyone send me a diagram or photos of this upgrade please? I believe i am getting air into my fuel lines.

A photo of how you looped the fuel return would be good enough.

Cheers all,

Maff

[Hoss]

oh and as for my Blow Off valve, i took someones advice of here and screwed it all the way in so it doesn't blow. i did it about 4 months ago and have had no problems what so ever and improved incline ability! Max speed on the straight 75 but wouldn't push for more