I installed the fresh injectors and the car still skips. Not as intense but enough to annoy me. When I loosen the number four delivery valve (less then hand tight) it idles and drives great, but it leaks fuel. When I tighten it the car puffs black smoke and skips. I can swap injectors and the issue remains in the same cylinder. I've done a compression test and all is well. I'm thinking about getting a complete delivery valve or a used IP. Any ideas?



Thanks again,
W.G.

New head gasket
Injectors popped @ 150 bar
Compression = 325 +/-15

I am no expert. Since the car idles and runs so nice with the leak. I would try to repair the delivery valve before even considering another pump. A lot cheaper as well. You might have been lucky to have found the problem as well. I know I would have been. I do not suspect it is the delivery valve though really, could be wrong. The only other concern I might keep in mind as well. That is if it is masking an element timing or volume problem somehow. More likely volume. The black smoke when it is tightened down leads me there. The element volume is adjustable if need be. I just like to see the need proven before the adjustment is done. Plus some thought put into it beforehand. It is doable. If you decide to correct the problem yourself post it. I will try to lead you through if you want. There are no absolute guarantees and you will have to own a digital meter. But it should work. The pump is most likely on it's way to a shop otherwise and on that basis there is no harm done if it does not work. You would be restoring the temperature of the fuel burn in number four cylinder to match the other cylinders average. It is also good that you did the compression check already. You have been running that cylinder at elevated temperatures I suspect. Not a particularily good thing. Probably no harm done yet.

After some reflection I am modifying some of my thoughts. I would get new delivery valve rubbers and copper washers for two delivery valves. Swap the position of the troublesome one with the one next door. If the problem travels you have it. With a little luck the problem will be totally gone with both delivery valves. If not you have the volume problem. The only concern is if the delivery valve is a contained unit on your pump and It should be I think. Valve and the seat and spring is one unit? This is perhaps the cheapest and most accurate test I can think of to start with and may very well solve your problem. Might just be poor seals. Read all you can about how to torque and change delivery valve seals in the archives. From what I understand they are somewhat fussy. I really do not like all the trouble and risk of starting to deal with an unknown used pump. It sounds like yours is basically a very good pump to start with. Wish I knew more and could be of more help. . Perhaps others with more knowledge will respond....Now if the problem does not dissapear or move it will be interesting. You are probably way ahead of me by now in thinking this out.

Well after pulling all my hair out I finally figured it out. There is a brass colored side cover on the IP that is directly under the delivery valves. I removed the four screws, removed the cover and took a long look inside. There is a rail in there with four clamped on slides that control fuel delivery to each individual delivery valve. All were evenly spaced except number four which was all the way to the right and loose on the rail. I moved it into the approximate position based on the location of the others, tightened it down and PRESTO, she fired right up and idled perfect. So after I did the rumba with the wife I came here to post.


Thanks for the help so far,
WG