csv and wrd problems

[frostpinfold]

I have spent hours and hours searching the forum for answers and am still very little wiser.
Symptoms are as follows. Engine starts OK from cold and after a few seconds idles fine. The car runs well when partly warm including idle at 800 rpm but once fully warm (say about 5 miles) it still runs well above 1500 rpm but misfires at idle and to get it to run properly you have to rev the engine. As if you are clearing excess fuel The engine sounds to me as if it is getting excess fuel but only at low speed when fully warm. 
I removed the small screw on the CSV and there's no apparent fuel leak. But could the CSV be letting excess fuel into the system?
Ive stripped and cleaned the WRD. The air flow at the filter stops once the engine is warm.
Engine was rebuilt recently by Crewe Engines. All compressions good. Have electronic ignition. New Magnecor leads, new distributor cap, new rotor, new plugs (Bosch W8DC).
I dont know where to go next. Any suggestions welcome.
Rob

[Dave H]

Search for the following video on you tube, it’s by far the best explanation of how our injection pumps are affected by the wrd, csv and how to shim and set them up correctly. Far better explanation than any book . Great if we could get permission to put it in our technical manual. I thought I had a clear understanding of how it all worked until I watched this video, every days a school day .

[WRe]

https://youtu.be/F6sxlOFmoYw
...WRe

[stickandrudderman]

Or this:
https://youtu.be/28uD3JVbQ-I

[Pawel66]

I think if you have issues at the low range of rpms, it may best to start from confirming if the mixture during warm idle is too rich or too lean or more or less correct.

But before even confirming this you would need to make sure again if ignition is set correctly and if the linkage is set correctly (would be good to check valve clearances too and I would not take for granted that engine rebuilders, unless it is really reliable service, did it correctly). For linkage set up, go through Linkage Tour in Technical Manual.

Simple test then to determine lean/rich mixture during warm idle is in the video from stickandrudderman. The adjustment was described in the video from WRe (I would skip the part about the WRD for now), but I think it is also very well explained in Linkage Tour. Please note that you may need to drive the car a bit after each adjustment attempt. Split linkage test can help determine too rich or too lean after each adjustment attempt. But in essence, after an attempt when after driving engine runs at 750-850rpms at idle nicely and smoothly - this is it.

The CSV may be the culprit if the mixture is indeed too rich. But if the first test showed no leak, what stops you from thinking it is not simply adjustment of fuel/mixture at idle?

Something different regulates fuel/air at higher revolutions, where you say you have no issue.

I would probably not mess around with WRD for now if you say it warms up ok and has issues at warm idle only. This would mean idle adjustment to me.

[frostpinfold]

Thank you all for the feedback. The video was very helpful. I reset the linkage following the Linkage tour and found the FIP was not completely closing, so that was worth doing.
 I have set the slow running mixture and the car is mostly running better but is not stable. What I mean by that is that the mixture remains good for a while and then without doing anything starts to go rich and the engine starts to misfire.
I took the car to the local garage with a gas analyser and the HC also is much too high (about 1800/1900). this means excess fuel.
Also the CO is at about 4% which Haynes claims to be correct.
However the CO is up at 8% at 3000 rpm which makes me wonder if the FIP needs rebuilding (or at least checking) so I think I will remove the pump and send it to Tower Diesels for testing but will probably wait till later in the year when the car comes off the road for the winter.
Thanks again for the suggestions
Rob