Beta 1505 - injection pump timing

[rgriffiths]

Some time ago I posted this question regarding a cracked injector pump. A few months on and I am still having trouble with this engine. Once started it runs well, but it is very reluctant to start. I have to turn it over for many times before I get any kind of bite, and this is with jumpers onto another boat. Clearly this is not a solution but I wondering what to do next to solve this one ....

 

This is what I have done so far:

 

• New injector pump. The old one had two shims for timing and I used these when installing the new pump.
• Had the head checked. A couple of valves reseated and skimmed.
• Compression is around 400psi in each cylinder. According to Beta would be 435 to 460 when new, but should run on 325 or higher.
• Injectors rebuilt.
• New glow plugs. Tested in situ and glow red when key is turned so seem OK.
• New diesel, filters, oil etc.
• The diesel looks fine, no water in the seperator. I have not polished the fuel and one suggestion is to try running from a can of new diesel. I have not tried this yet.

 

It is currently out of the water in a marina. A couple of the guys there have had a look, watched it try to start etc and said that I should consider the injection pump timing. I haven't done this before but have read the manual and done a bit of digging. The timing marks are on the flywheel which can't be reached due to the bell housing but I have a reasonably accurate measure using a screwdriver through injector 1 a cable tie and a mark on the pulley. Turning by hand it seems that diesel is delivered from injector 1 about 10 degrees after TDC. As an experiment I also took a video thinking I might be able to watch frame by frame. It is not very clear but this is what I can gather from it. The little red mark is 0 degrees against the white cable tie (crude I know).

 

 

So I am asking for anyone's thoughts. Does this look like it could be the problem? If so would removing the two shims deliver the diesel earlier and possibly improve the starting? A bit hit and miss I know but is it worth a go? Any tips gratefully received.

 

 

 

 

[Tracy D'arth]

Exhaust colour when running?

[rgriffiths]

Clear - all good. Quite white and puffy when turing over getting it to start.

 

[Tracy D'arth]

Just now, rgriffiths said:

Clear - all good. Quite white and puffy when turing over getting it to start.

 

That would suggest to me that it is retarded. Whip a shim out?

[Tony Brooks]

It makes me think more lack of compression than pump timing. Beta seem to fit undersized glow plug cables so what is the glow plug voltage when in use?

 

Just read Tracy's reply. You might as well try because you can always put the shim back in.

Edited April 29, 2021 by Tony Brooks

[rgriffiths]

Thanks Tony. I hadn't considered the size of cable and you are right it is a thin cable. The actual voltage I have not checked but removed a plug and clamped it to engine and glowed red hot on the turn of the key. I could upgrade the cable to see if that improves things. Certainly won't do any harm and did think it took a while (about 15 seconds) for them to get up to heat.

Edited April 29, 2021 by rgriffiths

[Tony Brooks]

4 minutes ago, rgriffiths said:

Thanks Tony. I hadn't considered the size of cable and you are right it is a thin cable. The actual voltage I have not checked but removed a plug and clamped it to engine and glowed red hot on the turn of the key. I could upgrade the cable to see if that improves things. Certainly won't do any harm and did think it took a while (about 15 seconds) for them to get up to heat.

That's no good, try it with all four at once but voltage is easier. If you don't have a voltmeter use a jump lead between engine battery positive and a glow plug positive and see how it starts with that.

[rgriffiths]

4 minutes ago, Tony Brooks said:

That's no good, try it with all four at once but voltage is easier. If you don't have a voltmeter use a jump lead between engine battery positive and a glow plug positive and see how it starts with that.

I have a voltmeter and will check it with all four. The jump lead is a good tip and will try that too. Thanks.

[Steve56]

You mention in the original post that diesel appears to be delivered 10 after TDC. For the engine to start and run correctly the fuel should be injecting before TDC.

[rgriffiths]

Yes - but my methods for coming to this conclusion are pretty hit and miss don't you think? I was really asking for tips to check the injection timing to confirm that it might be too far advanced.

[BEngo]

It should be possible to check and adjust the injection timing with the engine and gearbox assembled.

 

The manual would be a good start  but if not available I would start by looking round the flywheel end for covers or access points to see  the timing marks on the flywheel. A call to Beta may also help as it is also possible that the timing marks are elsewhere.

 

The injector pump is the in line type, I think, so you do not time it by the injection as such, but by the point when the fuel no longer flows freely through the injection element- spill timing. Injection follows after this, but with a little delay. Spill ending should be happening  some time BEFORE Top Dead Centre, not after as you think yours may be.  If yours is after TDC then the injection  timing is too retarded rather than too advanced.

 

N

 

 

[Steve56]

I am pretty certain that the timing marks are on the flywheel. Unfortunately on the majority of these engines there is no inspection hole in the gearbox adaptor so you would need to find an alternative way of determining the firing point. It may well  be worth a phone call to Beta and see what they advise. Personally I would not try to time this pump using the spill method as this involves removing the delivery valve. I would use the bubble test method where a tool is fitted to the pump and you can see the fuel rise in the tube as the pump operates. 

[rgriffiths]

 

This is from the manual. I can't see the timing marks as they are hidden by the bell housing which can't be removed and there is no inspection hole.

 

Having reread these instructions I will give it another go tomorrow as they make better sense to me now.

[Tony Brooks]

You can get plastic degree plates to fit on the front pulley but the problem is finding TDC so you can zero it.

 

This may work to a degree or so.

 

Fit the degree plate plus organise datum pointer.

Set no 4 on valve overlap (both valves moving at the same time).

Turn the engine backwards about an inch.

Take no. 1 glow plug out  and put a soap bubble over the hole.

Very gently turn the engine in the forward direction watching the soap bubble. It will probably burst so renew it.

When the bubble stops bowing out and stays the same size stop turning.

You may wish to back the engine off  a fraction and do it again.

Take a note of the degrees on the plate.

Replace the bubble and turn in the direction of rotation. At first the bubble should not move but as soon as it starts to suck back into the glow plug hole stop turning.

You may wish to back the engine off  a fraction and do it again.

Note the new reading on the degree plate and calculate the difference in degrees.

Halve that difference and turn the engine back that number of degrees.

No 1 should now be at TDC so set the degree plate so it zero mark is in line with the datum pointer.

 

Now you can do the spill timing and get the injection timing from the degree plate.

 

As long as you can work out a wya of fixing it I think you could use a school type protractor on the front pulley (double-sided sticky tape/)

 

[Tracy D'arth]

You can also do it without a degree scale or protractor by dividing the pulley circumference ( pi X diameter ) by 360. Each increment of this figure of the circumference is then one degree.

By measuring the part of the circumference you will find the degree of advance or retard.

 

Injection must be before TDC

[rgriffiths]

Success!

 

A little trial and error but ended up adjusting the timing by removing 4 of the 5 shims such that the timing went from a touch above TDC to around 18 below. And then ..... it started first time without any problems whatsoever.

 

The sound of the engine was a little different from before. It isn't knocking as such so I think the timing is good but is throatier than before - hopefully back to as it should be. The main thing is that the timing was clearly the issue and I can review the timing again after I have cruised it for a while. It is out of the water at the moment and so can't test it under load but back in tomorrow and fingers crossed continues to work well.

 

As ever, thanks for all the advice. Invaluable.

[Tracy D'arth]

The clue was the white smoke, a sure sign of late timing.

 

Different sound, has it a "bark" at half throttle? Sounds right.

Edited May 3, 2021 by Tracy D'arth

[rgriffiths]

Absolutely right - white smoke. And that is exactly what one of the mechanics said at the marina when he had a look at me trying to start it, although he claimed he didn't really know that much about engines. Only 40 years experience fixing them!!

 

A 'bark' ... I will have a good listen.

 

Thanks again