Idle speed after tuning

Just tuned up the fuel pump a little in the 90 (200tdi) - good results with power and no smoke. Only thing is the idle speed seems to be quite high now - I might be overreacting but still is there anything I can do about it without having to back the fuelling down?

Thanks,

wind the plastic knob on the accelerator cable where it connects to the fuel injection pump back a little

Have you checked the throttle cable adjustor? If the arm is returning fully you might need to back the top screw back a little

Ah right cheers for that I will check it out tomorrow.

If you have only tweaked the pump and nothing else, Just adjust the tickover screw!

What exactly did you adjust to turn up your fuel? If you wound the full fuel screw in at the back of the injection pump (which usually requires the removal of an anti-tamper tab), how many turns did you wind it in? You need to be careful with the full fuel screw - it adjusts the initial starting point of the fuel governor and if you wind it in too far, it can get to the point where it will continue to add more and more fuel and your engine will rev its bollocks off. One to two turns is generally all you'd want to do with the full fuel screw. Was the anti-tamper tab in place or was it just a matter of loosening the lock nut and winding it in? Could have already been wound in a turn or two in the past if the anti-tamper tab was missing.

As suggested though - if you're happy with the full fuel screw (or any other adjustments you might have made such as fuel pin / diaphragm / star wheel etc.) you can simply adjust the idle rest down a touch. Look down at the injection pump from the drivers wing and manually 'rev' the throttle. You'll notice that as throttle plate returns back to its resting spot, it stops against a piece of threaded bar. This usually has a locking nut securing it in place at the back side of the pump and requires a flat blade screw driver to adjust. start the engine and wind it out a few turns until you are happy with the idle speed.

-Tom

OK I will have a look to see what you mean. Although the mods seem to be making it drive nicely, I think I might just back it off just a little to be on the safe side. I wound the throttle cable adjuster out but it just made the loud pedal go slack.

All sorted - thanks for your help. Apart from getting the screwdriver in that very fiddly place it was very easy - didn't have to wrestle with the nut either which was a first!