Injector pump VP 2001

[paulwornell]

I recently had my injector pump serviced (along with the injector) and while the engine runs fine once started (after much cranking) I notice that there is over fuelling at near full throttle. So the question is, would servicing an injector pump change the timing and cause overfuelling. I understand that the timing is adjusted by means of shims inserted between the pump and the engine block and the thickness of the shims should add up to the figure stamped on the pump + the figure stamped on the block at time of manufacture. I simply put back the shims that were there previously.

Perchance such a pump service could alter the timing is there an easy way to adjust the timing (i.e. shim thicknesses). I have read the manual and it appears to require special equipment to get the camshaft in the correct allignment to then use a micrometer to measure clearances.

All advice and experiences welcomed.

 

[Bilgediver]

I recently had my injector pump serviced (along with the injector) and while the engine runs fine once started (after much cranking) I notice that there is over fuelling at near full throttle. So the question is, would servicing an injector pump change the timing and cause overfuelling. I understand that the timing is adjusted by means of shims inserted between the pump and the engine block and the thickness of the shims should add up to the figure stamped on the pump + the figure stamped on the block at time of manufacture. I simply put back the shims that were there previously.

Perchance such a pump service could alter the timing is there an easy way to adjust the timing (i.e. shim thicknesses). I have read the manual and it appears to require special equipment to get the camshaft in the correct allignment to then use a micrometer to measure clearances.

All advice and experiences welcomed.

This is more likely due to overload and the engine being unable to achieve the revs you are demanding. Back of the speed lever and the revs will stay the same but the smoke will go.

If the engine is now smoking under conditions where previously it had clear exhaust then check things like....Clean bottom.....clean propeller....shaft not stiff to turn...... and most important check the exhaust elbow is not coked up. This develops quickly especially if you run the engine in a smoky state.

It is highly unlikely the fuel pump needs adjustment unless it has been fiddled with.

Sometimes even the alternator can take these small engines into an overload state if trying to charge a flat battery where the alternator has a so called intelligent regulator. The revs might need to be reduced to allow this.

 

[paulwornell]

Just to be clear

Thanks Bilgediver - just to be clear, you refer to black smoke - when I used the term 'over fuelling' the symtom is (black) unburnt fuel in the exhaust water. I can confirm that when I ease back the throttle the unburnt fuel disappears - but I don't have a smoke problem.

Any other views??

 

[Heckler]

This is more likely due to overload and the engine being unable to achieve the revs you are demanding. Back of the speed lever and the revs will stay the same but the smoke will go.

If the engine is now smoking under conditions where previously it had clear exhaust then check things like....Clean bottom.....clean propeller....shaft not stiff to turn...... and most important check the exhaust elbow is not coked up. This develops quickly especially if you run the engine in a smoky state.

It is highly unlikely the fuel pump needs adjustment unless it has been fiddled with.

Sometimes even the alternator can take these small engines into an overload state if trying to charge a flat battery where the alternator has a so called intelligent regulator. The revs might need to be reduced to allow this.

I think the clue is in the words injector pump serviced!
How does one service the pump? Methinks an opportunity for pump shop to make money!
Stu

 

[Stork_III]

Thanks Bilgediver - just to be clear, you refer to black smoke - when I used the term 'over fuelling' the symtom is (black) unburnt fuel in the exhaust water. I can confirm that when I ease back the throttle the unburnt fuel disappears - but I don't have a smoke problem.

Any other views??

Do you mean black carbon deposits in the exhaust water? If so sounds like classic symptom of major restriction in exhaust elbow, causing excess back pressure preventing proper fuel burn. Probably made worse now by a reactivated injector pump. Skipper Stu, I think you're too suspicious.

 

[MoodySabre]

I think Paul would have cleaned out the exhaust elbow on a strip down in the last year or two. Would a collapsing (delaminating) exhaust hose have the same effect?

 

[Stork_III]

I think Paul would have cleaned out the exhaust elbow on a strip down in the last year or two. Would a collapsing (delaminating) exhaust hose have the same effect?

Possible, if the inner has inverted it could encourage deposit of same concretion found in exhaust elbow. I checked the elbow on my MD2030 recently which was ok only minor build up, but I did notice some build up in the rubber pipe downstream.

 

[paulwornell]

Lets try simplifying the question

Has anybody any experience of adjusting the injector timing on the VP 2000 series by changing the thickness of the shims - and if so how did they go about it?

 

[Stemar]

My understanding is that the shimming is critical. The workshop manual explains how to do it, download from here:

http://www.bluemoment.com/downloads.html

If you've kept the old shims and replaced them exactly the same, it's unlikely this is the cause of your problems, but it is something that sprang to mind reading of your symptoms. I'm no mechanic, but it seems to me that a missing shim would lengthen the pump stroke and cause overfuelling, which, I suspect would only be noticeable towards the top of the rev band.

Good luck!