Thread: 2.25D injector pump shudder

I can't see it being the injection pump failing to keep up - if it was not keeping keeping up, surely this would show up when it was pulling, not when there was no load. The problem seems ot be happening when the engine is at high rpm but throttle closed - it could be a problem with the governor function of the pump, but I would think it is more likely something else, possibly the injectors not functioning well at a combination of very low fuelling and high rpm, possibly something totally unrelated, such as soft or broken engine mounts or a dragging hand brake (I think this is a likely one).

If you have a intake throttle to provide brake vacuum as some of these had, consider the possibility that this is poorly adjusted, closing off too much of the intake.

John

worn pump guts....

whats happening is the govenor is over compensating and hunting to try and keep it at idle, think like you did when you first learnt to drive a manual and how you used to try to work the loud pedal to stop the bunny hopping you inevitabley did at first. The govenro and other inernal wear is doing just that..

Fortunately you can temprarily con it (if it hasnt already been done) by lifting the IDle RPM other than that the pump needs to be pullled down and at a minimum have the weight pivots and the springs adjusted. it might also be that the idle has been set too low. 650rpm is about right but 700 seems to work better.

your injectors will also be contributing if they are not set up with the same crack pressure or if they arent spraying really nice, in over run conitions they only get a little fuel and it may be injecting too late into the power stroke to be doing any good or not atomizing it correctly.


Try this..

In stead of snapping the noisey pedal closed, ease off it gently and see what happens.

Roger that!
The PO renewed everything except the pump when he put my car together.
Apparently he just found an old injector pump, bolted it on and it worked, so that was enough.

I've been aware that I need to get it serviced. My power is down (compared to other series LRs) and lots of smoke follows me up hills. I still manage 10L/100kms, however.

I'm rather concerned at the potential price of the injector pump service, so I'm holding off for the time being. Is it a ticking timebomb, or will it keep on truckin'?