Strip and rebuild 2.8 IP

[solarman216]

Cam roller plate

 

[solarman216]

Springs plunger and control sleeve

 

[solarman216]

Head ready to go on

 

[solarman216]

Advance piston springs

 

[solarman216]

Governor the prior pic is where the fuel leak was, I guess that the springs must have moved the O ring

 

[makeitfit]

Nice work Rick. I was trying not breath when I rebuilt my T2 pump..all I could think of was your mantra, clean , clean, clean ��

 

[solarman216]

Throttle spindle and springs

 

[solarman216]

Delivery valves

 

[solarman216]

Ready to go back in the motor or so I thought

 

[solarman216]

No bits left over, always a good sign

 

[solarman216]

But does not always work like that, do what I might I could get no output nothing not even a dribble, so off it comes again and strip it down thinking I must have done something silly like put something in back to front ( the control sleeve for example) but no all was in order, so next step was to pipe it up on the bench with a fuel supply and whack it over with a drill, still nothing, much scratching of head and strip it down again, suspecting it might have something to do with the annular groove on the original decided to put the old head back on, still nothing, now I am getting peeved, after removing the top chamber and the plug in the end of the distributor I was able to check the position at which the control sleeve stopped the flow of fuel, this is important for starting as with fuel flowing in this condition there can be no high pressure fuel delivery, I then measured at what point the max fuel screw should be screwed in to = this point and was very surprised to find it was a lot more than my initial setting.

Now just to recap here I am aware how important this screw is so when I stripped the pump knowing that to get the top housing back on with the screw in place is next to impossible I just slackened the lock nut and removed the screw with the nut marking the original position.

So put it all back together with the screw set as above and ran it up, almost immediately dribbles of fuel and after a few seconds 6 regular shots of fuel over the work bench, eureka.

So now having discovered the pump is fine stripped it down again and re fitted the new head and plunger and same result, so stuck it on the motor and it runs but not very well, no power at all so looks like some more fettling with that max fuel screw, but had it for today, Rick

 

[solarman216]

Nice work Rick. I was trying not breath when I rebuilt my T2 pump..all I could think of was your mantra, clean , clean, clean ��

I have a dirty workshop so by my side is a bucket with 5Lt fuel in it, every part before fitting is swished around in this as is every tool I pick up and use, Rick

 

[solarman216]

Found a video by Bosch that documents the difference between the groove and non groove plungers, I have watched it 4 times this evening and need too sleep on it to get my head round it, but clearly it makes a difference, Rick

 

[solarman216]

The net effect of the plunger I have as opposed to the old one removed is that the new one starts injection much sooner so my pump is in effect far too advanced but I fear just retarding the pump by what is needed will not cure it as doing that will upset other parameters, another possibly better method would be to grind the end of the plunger to match the old one, but I need to think on that a bit, Rick

 

[solarman216]

Decided that I will put my old distributor head back Wednesday /today and look at grinding the new plunger with a groove to match the original, I will never be beaten, Rick

 

[Flying Torquewrench]

Nice bit of work Rick. Always very satisfying when you can find the culprit. Would you be able to turn the groove into the new plunger instead of grinding?

 

[solarman216]

Love to be able to turn it but it is HARD metal, had a quick play this afternoon, stuck it in the lathe and set the mini angle grinder up with a 1.5 mm cutting disk the groove is 2 mm wide so headed for the centre so now have a 1.5 groove which just needs cleaning up but eyes had it for today, had a chat with a diesel shop who thinks he may be able to get me the correct head from Bosch in Germany but not till August or so, Rick

 

[solarman216]

OK well latest update, when I removed my original head I did not bother to check the "k" value as it was not of concern, the new one came in at 3.33mm and given the tolerance is 3.2 to3.4 I was quite happy, so before refitting the old one I checked this dimension and horror it was 3.49 so needed a 0.2 shim, now I thought straight away about the ones I bought for sorting the cam followers and indeed there as a pack of 0.2 only trouble is they are a tad too big in the diameter, so ground it down a little, placed it in the recess first and the much thicker original after with a bit of grease to stop them falling out on assembly, net result now it is all up and running is hot starts whilst not perfect are one hell of a lot better, so a good result, and just so you can see here is a pic of the new plunger with the groove in its present state, it needs to be widened on both sides and a little deeper but it needs to be very accurate, so a lot of thought will be needed to accomplish this, but the pressure is off for now, Rick

 

[Flying Torquewrench]

Excellent Rick!

I read a post on a forum a couple of months ago but I can’t find it at the moment. This post was regarding hot start problems on the RD28T. The fuel pump wears out and when it gets hot it expands leading to internal leakage, resulting in a difficult to start engine. You can buy new pump internals that sort this issue.

Just a FYI. :thumb2

 

[solarman216]

That is exactly where I am FT but buy a new head!!!!! that is why I got a pattern part from China but as we now see it has a different plunger hence the mod, Rick