My project 2.5 estate has been on the road for a couple of months now but is not well, it lacks bottom-end performance and is drinking fuel. I have worked through a diagnostic process and reached a conclusion as to what I think is wrong with it and should find out if I am right in the next day or so...weather permitting.
I thought I would post up the symptoms and the results of my tests to see if anyone comes to the same conclusion but if I am right then I suspect there will be others suffering with the same fault.
A bit of history: It was bought as a runner but "makes a rattling noise". The cambelt tensioner had failed and the passenger bank timing was 2 teeth out. A new cambelt kit had it idling smoothly but it wouldnt rev over 2500, this was fixed by a new fuel filter. It passed the MoT and I started using it which is when I realised there was something wrong.
Symptoms:
Revs freely to 6750 but lacks torque and bottom-end 'grunt'.
No hint of a missfire or un-even running.
Fuel consumption is 22mpg at best on commute (my Elite used to manage 27 on the same run).
Air mass meter OK and coolant temp sensor OK.
looking back at the MoT emission test:
lambda slightly high
CO at top limit
HC slightly raised
Manifold vacuum low at 17.5" Checked all the breather seals, vacuum pipes etc and eventually changed the manifold and bridge gaskets...no improvement.
EGR valve blanked off...no improvement.
HT leads, plugs coil etc checked.
Compression test shows drivers side 15 bar, passenger side lower at 13 bar.
Back to the vacuum gauge, when I hold the rear multi-ram open by hand the gauge oscillates rapidly between 21" and 14".
So what do you think is wrong and how do you account for all the symptoms?....