Richard, you are dead right! By the looks of it, that is a replacement, much earlier engine. You can tell by the spring clips on the cambelt covers for one thing.RichardW wrote:I suspect this car had a replacement engine
The pump is indeed a mechanical VP20 Hibbo but someone has put a VP20-AS3 load pot on top of it that is doing nothing and have also put a Needle Lift Sensor Injector in and connected it but it'll be doing nothing at all of course as the pump lacks the timing control electrovalve. Nor is the Needle Lift Sensor except perhaps helping to run 9and confuse) the tacho. The tacho can run from either the TDC sensor or the Needle Lift but normally from the TDC sensor.
Thast age of engine should also have had the waxstat type fast idle control. It explains now why the original vacuum operated fast idle cable could not be connected.
It's OK to run like that and in fact can be made good but work is needed. I've done a temporary transplant of a mechanical pump in place of an AS3 in the past with good results. You can in fact dispense with the load pot on top of the pump, leave the pump connectors disconnected (except for the stoop solenoid of course) and all will be fine but I'd say from the running problems you describe, trhe pump needs its timing checked. Timing on a diesel is very critical. It can be done by ear by rotating the pump until it just starts to knock and backing off a tad. The ECU has to stay in place to operate the tacho and the glowplug control unit. Defeat the Engine management Light by removing the bulb!
Best, in the long run, would be to source an AS3 pump and fit it but you will need to have it de-armoured to defeat the immobiliser or get one complete with keypad and a known code.
Before that though, how well does it start? Any smoke on startup and what colour is it? Does it sound a bit quiet for a diesel? Quiet running is a sure sign of retarded timing.
To defeat EGR, locate the valve on the exhaust manifold. It's on the right hand side (as you look under the bonnet) and looks like a little lantern. Pull off and plug the vacuum hose. Mind you, the engine, being early, would not have had EGR originally so it may not even have a valve. In which case the vacuum pipe may be there dangling, open, leaking vacuum and thus upsetting the brake servo.
although it is a p-e-t-r-o-l! 