Hi mate,
Its all fixed, but just for future reference if anyone has the same problem....
My problem was that I was getting a slight bit of hesitation at around 2k RPM and a drop in MPG. Not when booting it, but just when accelerating normally. Felt like almost a slight misfire.
I had disconnected the MAF and the problem was better, but still there, so I connected up the MAF to the diagnostics and it was giving out good readings and a smooth curve so I decided that it wasn't the MAF at fault.
I then took apart all the boost pipes and cleaned them out with compressed air. I also cleaned the boost solenoid with some carb cleaner, and checked it was opening and closing properly which it was.
I then disconnected the EGR valve and had a good look at it. It was remarkably clean considering they normally get quite gunged up! The valve was sitting properly and appeared to be free moving. So to test if the EGR was causing the problem, I made a small blanking plate out of 1mm mild steel and put it between the EGR valve and the inlet manifold. Problem was gone and car was much "crisper". No more power than normal, it was just a much smoother delivery. (although the car ran a little hotter. Nothing damaging, just over 1/3 temp)
SO...took the EGR off, and tested it with 6v source. The solenoid was intermittently sticking out before flying back in. I then completely dismantled it and cleaned it all up thoroughly and lubricated the solenoid at the back of it. Tested the operation of the solenoid using a 6v supply and all was working fine. Replaced the EGR valve on the car and removed the blanking plate. Jobs a goodun!
So to sum up, symptoms were:
~Slight hesitation (like a misfire) at around 2k RPM when accelerating normally
~Decrease of MPG
Just in case anyone else has a similar problem...thats how I solved it on my JTD.
Hope my bumbling experience helps someone,
Alan
