Shimming Penta 2001 fuel pump

[Midday Gun]

I have an issue with my 1986 Penta that I'm hoping someone can help me with.

I'm refitting the injection pump to a Penta 2001 diesel.

Now according to the workshop manual, the procedure is to take the number on the pump (in my case 16) and number on the engine, add the two together and then shim up to the required thickness using two soft shims and one hard shim.

When I removed the pump instead the two soft shims disintegrated when the pump came off and there was no way of measuring them.

Unfortunately my engine block does not appear to be stamped with the number I needed to shim the pump correctly, I've sanded away loads of paint in the area, and still can't find it.

I called volvo and ordered the two thickest soft shims they sold and reinstalled it with the hard shim that came out when I removed the pump. The theory being that if it was overshimmed I could drop it down.

Unfortunately this nearly turned into a disaster as once the engine started it immediately tried to run away, despite throttling back and pulling the stop cable. Luckily I was able to get a rag into the intake which while not stopping it kept it in check long enough to take off the injector pipe and kill the fuel supply.

After stripping off the pump again it seems my hard shim is only 0.3mm. The two soft shims i have are 0.25mm each making a total of 0.8mm.

If the number on the pump is to believed then I need at least 1.6mm total plus whatever the block number should be. So I've no idea what they used to shim it last time, but it seems like it was a non volvo shim.

Apologies for the long winded post, just trying to post some background info.

My question is, how can I determine the timing / shim thickness without the correct volvo setting tool? There are no timing marks, and my local volvo agent has already said that its beyond them.

Thanks for any help!

[Paul L]

Why didn't the stop cable shut off the fuel?

[Midday Gun]

Originally Posted by Paul L

Why didn't the stop cable shut off the fuel?

I have no idea, it was working before the pump was removed. My assumption (probably wrong) was that by the pump being much closer to the block then before (shimmed lower) then its still pumping even when it shouldn't be.

The pump literally just slides on two studs on the engine block and sits down on shims, I'm not sure how I could really install it wrongly as I didn't touch anything to do with the throttle controls.

[Paul L]

Originally Posted by Midday Gun

I have no idea, it was working before the pump was removed. My assumption (probably wrong) was that by the pump being much closer to the block then before (shimmed lower) then its still pumping even when it shouldn't be.

The pump literally just slides on two studs on the engine block and sits down on shims, I'm not sure how I could really install it wrongly as I didn't touch anything to do with the throttle controls.

I don't see how the shim position would affect the fuel shut off.
Maybe DougR will jump in with some of his knowledge.

[Midday Gun]

I don't really know the mechanism that the stop lever uses to cut off the fuel.

My thinking was just that the only thing that's changed is the height of the fuel pump, I haven't touched anything else that could have caused it.

[DougR]

Seems like two seperate problems here: pump control and pump timing

Control: When you have have the pump in your hand you will see a small lever on the body of the pump below the gasket surface and above the spring. When the pump is installed this lever is moved left and right by the control rod and its function is to turn the plunger in the pump body thereby lengthening or shortening the duration of the injection stroke, thereby giving more or less fuel.
The control Rod is the flat piece of steel which you can see down in the pump cavity in the block. The control rod is moved by the governor in response to your movement of the throttle cable or stop cable.

When the pump is placed into the block, the tip of the small pump lever needs to drop into the notch which you see in the control rod, thereby allowing the governor to control the fuel pump output. If you miss the notch, the pump lever lands on top of the control rod and when the pump is tightened it binds up everything....pump, rod, etc. This results in the situation which you encountered.....engine RPM which can't be controlled.

Hopefully, nothing got bent or damaged during this episode. After installing the pump you need to be sure the control rod can float freely fore and aft. This is done by removing the large hex head plug on the rear face of the block aft of the injection pump area. The aft end of the control rod resides there and you should be able to move it fore and aft easily.

Timing: This is a bit more of a problem........
Timing can be set with the special tool, or a degree wheel and fuel flow pipe(Wilber tube), but probably the easiest thing to do is just what you have done.....two soft and one hard shim. I think I would go with one thin gasket and one thick gasket, as that puts you in the middle of the adjustment range.

Failing that, scrape off all the paint around the pump opening in the block and see if you can find any markings. Consider no markings to equal "0".

DougR

[Midday Gun]

Thanks for taking the time to type all that out.

I'll have the pump back off and assuming nothing damaged, reinstall it following your advice.

[Midday Gun]

I refitted the pump and you were right, the tip had not dropped into the notch as it should do.
The part on the pump was ever so slightly bent, but I was able to straighten it.

However the problem I have is that while the stop cable moves control rod when pulled, the throttle cable has no effect at all. So I can only assume that it was broken when I adjusted the throttle with the pump in the locked position.

So I guess my next task is to strip off the parts until I can get to the broken linkage.

[DougR]

The control rod is moved by the throttle cable thru a spring and lever system that is then balanced by the governor weights. Thus the control rod more or less floats between throttle spring pressure and governor weight pressure. When you move the throttle cable you raise or lower the spring pressure and that results in control rod movement and RPM change.

It's possible that the throttle controlling spring was broken when the control rod was locked up, or something got bent at that time.

I suggest you take a look at the parts book breakdown for the fuel control system of the 2001. This will give you an idea of what things should look like and where to look for potential damage. You can find the schematic online at "marine parts express" or VolvoPenta marine parts Europe. If no luck there let me know and I can attach the page here.

DougR

[ShaktisBoy]

Exactly which engine is this? I just had to learn how to rebuild my D1-30s governor system in the last few weeks after a nasty oil leak developed. On ours at least there are 3 springs plus the centrifugal governor attached through a series of ride plates. The throttle. Control arm attaches to the pump rack on one end and a pivot point inside the timing cover. If any of the internal springs is stretched or detached you can get a throttle run away. The stop lever if you haven't taken off the timing cover engages the throttle
Lever and pulls the fuel rack to the cutoff position. The fact that it didn't work makes me suspect the pump rack is sticking open. On ours if I pull off the fuel cutoff solenoid I can see that the pump rack is indeed operating correctly.

[Midday Gun]

Thanks for the replies guys. Its the 2001 model.

I removed the cover that has the throttle arms going through it and took out the control rod and the throttle plate, sliding it back through the access hole on the back.

The throttle plate was bent in the middle, most likely from where I had screwed the pump down onto the top of it, and wouldn't run freely. This had caused the nut that screws onto the end of it to pull off the the threads, luckily not damaging them. I straightened the plate out by hand and reinstalled.

It now slides freely, however there seems to be a quite a lot of play in the throttle arm, I believe this is down to how I've installed the two springs, one that goes onto end of the control rod, and the other at the top of the linkage arm. The plate doesn't want to spring back to the correct position.

I've printed out the drawing so I can check it when I next get onboard.

[DougR]

It may be that you have installed something wrong, so you should compare with the parts book schematic. You will notice that there was an early and a late production arrangement with 23, 23a and 23b.

But when you move the throttle cable, lever #31/28 pulls on spring #25 and spring 25 pulls on lever # 17 and moves the top of 17 toward the front of the engine. But 17 pivots on pin #18 and the lower forked ends of 17 (which ride in the groove of sliding sleeve 16) move aft against the governor weights.

There isn't much force pushing the control arm/throttle plate aft toward the less fuel position if the engine isn't running. However if the engine is running the governor weights press against sleeve 16 which causes 17 to pivot against spring 25. This balances the system.

DougR

[Midday Gun]

Originally Posted by DougR

There isn't much force pushing the control arm/throttle plate aft toward the less fuel position if the engine isn't running. However if the engine is running the governor weights press against sleeve 16 which causes 17 to pivot against spring 25. This balances the system.

DougR

AH! Yes that makes much more sense!

On the attached diagram, I have part 25 facing the wrong way around. Which I will rectify when back, apart from that everything else appears ok.

Part 22 had pulled off the end of the control rod, and the plate (44) had been bent by the protrusion from the fuel pump pushing onto the flat surface instead of seating in the hole.

So once I've got everything in and moving correctly I can do another test run, given that it tried to run away before, I'm confident it'll start, but is there anyway of telling from how it runs if the fuel pump needs to be shimmed up or down?

[DougR]

I think it will be hard to tell much from how it runs, but in general:

Hard starting- injection timing is too advanced.....pump is too low

Engine is sluggish and smokes under load- injection timing is too retarded....pump is too high

DougR

[Midday Gun]

Originally Posted by DougR

I think it will be hard to tell much from how it runs, but in general:

Hard starting- injection timing is too advanced.....pump is too low

Engine is sluggish and smokes under load- injection timing is too retarded....pump is too high

DougR

Thanks for the help, the good news is its running!

Starting however was a chore when cold, I think the timing is way too advanced, I managed to find the number on the block (I was sanding off paint in completely the wrong area) and its 3.
Number on the pump was 16.

So total shim depth should be 1.9mm.

The problem is that the thickest metal shim available is 0.9mm, and the two thickest soft shims are 0.25mm each which gives a total of 1.4mm.

So that leaves me 0.5mm short.

Is it possible to double up the soft shims, or go for 3 soft and 2 hard shims?