Lots of Clicks - Mixture Still Rich

[tel76]

You are correct in your assumption that the screws under the plunger if unscrewed allow the plunger to be moved left or right so that more or less fuel is delivered to the injector.
It is not a good idea to carry out this operation insitu, the pump should be removed and placed on a calibration machine so that all six plungers can be set equal.
I would suggest that the operator did not carry out the calibration with enough care.
I have some experience with setting up these plungers (albeit on diesel engines, same principle) and it is a very time consuming exercise to get it correct, you need the patience of Jobe.

[Pawel66]

Eric,

Thank you! It is even more tempting now... What can go wrong?

It is probably a balancing act: when you allow more movement to have more flow for some, the others may pump less. So it looks like a lot of trials and checks in the garage without precise result probably.

Operation carried out with not enough care? This is very very likely.

What you say is giving hope that this is just a calibration exercise and not some fault that would require spares etc.

Thanks!

[Jonny B]

"It is even more tempting now... What can go wrong? "

OMG - please be careful with that phrase! Whenever my friend and I set up for a job, be it regular maintenance or something "simple" the Pagoda never ceases to surprise us with something.

[Pawel66]

  That's the fun part of it!

[tel76]

Pawel,
If you are going to ! Have A Go ! can I suggest that you connect a pipe to the injector pump outlet on say number one, bend the pipe over until it is pointing down, place a small measuring container under the pipe, crank the engine for 15 seconds and note the result (you could do this on all cylinders if you wanted to).
Connect up the pipe to your suspected cylinder/ outlet and crank/run engine for 30 seconds compare the two results, if there is a large discrepancy you can undo the screw and turn the unit a small amount (and I mean a small amount) carry out the 15 second test, you will have to do this several times until you are happy with your calibration.
If you are not happy with the results then you will have to remove the pump and send it to the repair facility for calibration.
As you have had the pump at a Bosch service station then the item should be under warranty, if you carry out the above and find that number three is incorrect, I would urge you to send the pump back and inform them of your findings, they then should carry out the calibration FOC.

[Pawel66]

Eric,

Thanks again!

The bent piece of line connected to the fitting on the pump - this is exactly what I did to measure fuel delivery to eliminate the fuel line being clogged! Happy we figured out the right way to do it!

I have the measurements noted to know what the delivery should be. It was 0.85ml on suspected cylinder per 15 sec cranking and 1.15 on others.

The three questions I would have are:
1. If I have the square plate of the pump unscrewed (to see the plunger units) while cranking - I guess I would have a flood of oil coming out - true or false? If true, it is probably about unscrewing the plate, moving unit, screwing it back, cranking to measure.
2. If I want to increase fuel - do I push the left side of the unit in or the right side? In other words: do I turn it clockwise to increase (looking from above) or CCW? This is to improve my chances by 50% to save one iteration - I do not think I will be able to see how the helix detent is cut in the plunger to determine the direction. From the rack movement - it should be CCW, I guess  .
3. Finally, just to make sure I mean the same things: I undo the screw on the element from the picture called "gear" and I turn the "gear/plunger" - is this correct? I think this "clamp" with a screw is a separate element, connecting with rack. I am attaching a scetch with what I think is a plunger unit similar to ours. I undo the screw 11 in clamp 10 and turn 9 with the bottom of 13. Is it correct?

I know I will never get it perfect this way.

Yes, it was a Bosch service - almost three years ago... warranty is gone. I have already called them, they said they would be happy to help and say sorry if they did not do it right. So it is not about the money, it is about lots of work and time. Therefore I am tempted to try to do it roughly now and send the pump in the  winter.

What is even more important: can you imagine my level of satisfaction if I manage to improve the fuel delivery?

[tel76]

Pawel,
In answer to your query -
 1 - Yes you will have oil gushing out of the pump with the front cover off, if the pump was on a calibration machine only a small amount of oil is put in the pump therefore there will be no excess to come out.
 2 - It is many years since I carried out this operation and the pumps I was used to were CAV and Simms units as fitted to British commercial vehicles. Your first adjustment will have to be trial and error.
 3 - Slightly undo the screw and turn the element/plunger that the gear (you cannot turn the gear it is aligned to the rack) is clamping, there is a special tool for this operation but I feel sure you can manufacture something to do the job.
I can understand your reluctance to remove the pump but it is not too arduous and you would get the unit calibrated correctly (this time) with the Bosch service centre, they would want to do it correctly this time.
Are you doing this yourself or paying a mechanic to do the job?

[Pawel66]

Eric,

Thank you again! We will then see how it goes when my mechanic comes to me to either try to calibrate or to remove the pump to take it to the service - we can open the flap, see if the screw can be undone easily, see what we would need to make adjustment etc. It is true, it takes us about 1-1.5hrs to take the pump out, it is not a major catastrophy. May just get a bit messy...

Yes, I would do it with my mechanic - for this I am not paying for as this is part of overall car delivery - just happens late 

By the way - I found another place in Poland, another Bosch service who have the appropriate testing table for our pumps and a set of specs for R25 and other types - they may just not have experience yet. I am sure we will try them next time. Just calibration (no spares, no extra time for repairs etc.) is $170 - can live with that. The current Bosch service we use is quite far and away from motorways from Warsaw, very inconvenient if you want to go there yourself ("far" for European standards, of course).

Thank you for your kind attention!

Pawel

[Pawel66]

Short update again...

My mechanic helped me with my dilemmas whether to do the calibration ourselves or take it to Bosch: he looked at me, went to the car, removed the IP and took it to Bosch...

In the Bosch service it took them 1.5 hours to set up the test table for this type of IP and then 15 minutes to check it and calibrate it to specs. The fuel delivery was way off between the lines, around 30%.

They said sorry and took no money.

Most likely we will install the IP tomorrow. Thrilled to see if it helps...

[450sl]

Pawel, you might consider turnig the Ip on correct timing point marks and take measurement on 1 outgoing fuel line (like the toothpick method).

Then after mounting you can easily check if timing is spot on.

[Pawel66]

Yes, thank you! It is another important point! I have actually exercised this and I did have the IP reversed before - I thought at some stage this was the reason for my idle issue. It was the classic "first cylinder - first fuel line" mistake!

So - thank you! I am very familiar with it as I read all the posts and procedures for timing the pump: the 20 degree ATDC in power stroke and the marks on the pump and where the plunger in line 1 should be and, what is very important - which fitting is for line to cylinder 1.

[Pawel66]

The IP is in the car.

The shaking idle is gone!!! I do not want to praise the day before the sunset, but I had a chance for a short ride and idle is just a bit rough - but I think this time it may be tuning as the car runs rich. But it is completely different form what it was before!

Need a couple of hours to check the basics again and try to tune the car. I hope this will be it!

[Pawel66]

Click after click (on the main adjustment screw for now) the plugs are getting brown. Looks like now we are talking (fingers crossed). I will do the proper measurement of CO and other unpleasant gases as soon as I get the required combination of Sunday, nice weather and the guy in the only car testing station that is open on Sunday nearby is not on holidays. This may be this Sunday.

[stickandrudderman]

Still waiting to see what HC you have now!

[Pawel66]

I will come back with the final one, I have not forgotten. It is just taking some time due to factors listed above We did another adjustment last Friday but could not go to the station to do the measurement...

[Pawel66]

Just for update and maybe to proboke some comments. Sunday week ago was a perfrct combination of all factors to go to examination station and get the CO reading - went there, to find out the guy took the instruments to calibration. Be back on Tuesday  .

What we found in the meantime, however, was that  while the valve nests were ground, the thrust washers (shims) were left nominal, 4.5mm. Maybe this is why I am getting too much mixture to cylinders...

[Tom in seattle]

I've followed each post on this thread and wonder how or if the problem was resolved by Bosche rebuild of your injection pump?

[Pawel66]

They just adjusted it, they have rebuilt it earlier. The adjustment was about making the pump deliver even amounts of fuel per cylinder. It is fine now.

I have now good idle, light brown spark plugs and by split linkage test the mixture seems to be more or less in balance. I got to the point where, when I select a gear (4 or R) on automatic transmission, I do not really feel or hear the revs change.

What I still have not done is the CO, CO2 and HC tests to check where I am on these. Now the weather is awful and I do not move the car from the garage, so, unless there is a nice day in the winter, I will check the parameters in the spring. My attention went now to camshaft that, as I figured, is not in the shape I would like it to be.

But I am not sure if IP is your concern. I started doing it because I had uneven idle and I was figuring out why, did some tests and discovered IP issue. You may want to focus on simple things we listed maybe.

[Shvegel]

If for some reason the rough idle returns I would keep in mind that a leak between the top of the pump barrel and the delivery valve could also cause low delivery.  The barrel seals to the delivery valve with no sealant and rely's only on the flatness of the surfaces so any dirt or imperfection can cause an internal leak in the pump where fuel would leak back to the fuel supply.

[glenn]

Hi   At idle an engine should be burning 4-6 ml/min.  Say 1ml/min from each piston.  Seems they ought to be within 5% of each other.  Carbs do better!!??  At 60 mph that's 250 ml/min.  15 mpg or so.

[mrfatboy]

Looking back over my notes from when I had my pump calibrated by Jerry Fairchild he told me that the FIP should put out 16cc (16ml) at idle.  My pump is for a 280.

[Pawel66]

When I was testing this with fuel lines dripping fuel to a file or syringe, I did not know the specs, but I was after the amounts for cylinders being equal or not. And they were 20-30% off... Now I have specs for R25, but it is difficult to recreate the conditions of measurement and the specs are giving amounts by given number of piston strokes. So what you are providing is very valuable.