BMC 1.8 failure to start after tickover cut out

[john.k]

Probably air in the pump..........although DPA hydraulic pumps also rev with fuel starvation,but then die immediately load is put on the engine.

[marksbrown]

Okay so I need to crack the union nuts and crank for another 30 seconds / minute? There's definitely clean fuel in the line and tank. I'm certain the filters are seated properly (no twisted seals) as I didn't do it - an engineer did! Thanks.

[john.k]

Best way to bleed IMHO is to get the motor going ,and then bleed the screws and injector unions in series ......gradually the motor should settle down ........I never start first up without slightly cracking all the injector nuts ......the motor will still run ,and air bubbles out of the unions ,then you can nip up the nuts in order ...always finishing with the uppermost fuel connection on the pump........the motor should run evenly by then..................you also need to be careful not to "foam" the fuel in the filter ,as air will take ages to settle out.

[Tony Brooks]

56 minutes ago, marksbrown said:

Okay so I need to crack the union nuts and crank for another 30 seconds / minute? There's definitely clean fuel in the line and tank. I'm certain the filters are seated properly (no twisted seals) as I didn't do it - an engineer did! Thanks.

 

That suggests that you may not have bled the injector pump. In this case, I would bleed from the bleed screw on the side of the cylindrical body AND the one on the throttle turret (if your pump has one there - not all do). Keep bleeding for 30 seconds after it seems all the air has gone. Only then bleed the high pressure side from the injector unions.

 

However, it sounds more like a stuck governor valve to me, but why it has stuck if you have not been messing with the pump I have no idea. If you have no success, come back, and I will try to describe how to check the valve.

 

Edited to add: further thought. following on from JohnK's comment about revving with fuel starvation, I wonder if during your efforts to get the box off and on, you have kinked or otherwise damaged a fuel pipe or inadvertently turned the fuel tap partially off so fuel flow is restricted once the engine revs.

Edited February 22, 2023 by Tony Brooks

[Tracy D'arth]

Has the throttle cable got pulled or mangled whilst you were struggling with the gearbox?  If in doubt after you have bled the fuel side, disconnect the cable from the lever on the pump and try it by hand when the engine is running.  You need the return spring on the pump lever.

[john.k]

I would think it impossible for the governor valve plunger on a DPA hydraulic to stick .............for sure the valve on a mechanically governed pump will stick ,Ive had it happen many times when I used aviation kero in my tractor...(never again on that one)

[Tony Brooks]

16 minutes ago, john.k said:

I would think it impossible for the governor valve plunger on a DPA hydraulic to stick .............for sure the valve on a mechanically governed pump will stick ,Ive had it happen many times when I used aviation kero in my tractor...(never again on that one)

 

I can assure you that they can and have, especially if a small blob of water gets into it. However, as the Op says it stops on the stop control it means the stop is pushing it down to the no fuel position, and as it then revs up the valve must be lifting, I think you or Tracy may well be correct - fuel starvation or something wrong with the throttle cable.

[john.k]

Fuel starvation is commonly caused by watery sludge blocking the white nylon filter in the pump inlet ......this is easily cleaned by blowing with compressed air ,or you can use a fine jet of water from a kitchen tap .......,Blow out the sludge from the inside ,until the filter is clean enough to see light through the fine mesh.

[Tony Brooks]

Just now, john.k said:

Fuel starvation is commonly caused by watery sludge blocking the white nylon filter in the pump inlet ......this is easily cleaned by blowing with compressed air ,or you can use a fine jet of water from a kitchen tap .......,Blow out the sludge from the inside ,until the filter is clean enough to see light through the fine mesh.

 

I am reluctant to suggest taking that filter out unless there are good indications it is needed, too much opportunity for the inexperienced to introduce dirt. Then there is the potential to lose the regulating valve and springs.

[marksbrown]

Okay so points in order.

 

1. I cleaned the fuel lines from the tank to the injection pump, bled through step by step and left overnight. I checked this morning and noticed a small leak on the input of the water trap. I cut the hose and replaced the jubilee clip. I've then bled through again - no issue.

2. At the injection pump on screw 3 (low pressure screw on top) creates a lovely arc of diesel when bled using the lift pump.

3. The air bleed screw on the injection pump governor housing opened until the larger hex moves (but not much further) leads to a dripping off diesel with the lift pump.

4. With the domestics in parallel I then bled the governor and high pressure screw (screw 5 on the turret) which showed very little diesel (barely enough to get blue roll damp).

5. Tightened both of the above and with the injector unions open, I cranked again. None or very little diesel seen despite cranking for > 20 seconds. Can try again if required.

 

Given that diesel is reaching the injection pump on the low pressure side but not getting beyond does that imply a blockage of some sort? Should I be cranking the starter motor for longer?

 

edit :: additional information.

The stop lever is stiffer than I remember it being. In all cases when I've been cranking, I have the throttle lever set to max with the stop lever fully down.

Edited February 27, 2023 by marksbrown

[Tony Brooks]

You will not get much fuel from the injector unions, probably less than a pinhead's worth every two revolutions.

 

I am assuming that the screw numbers refer to your manual, which I do not have.

 

The screw that you refer to as number 5 is, I assume, the one between the throttle and stop levers. This is not a high pressure screw except that when running it, plus the other screw, are at transfer pump pressure which is a little higher than lift pump pressure, however when bleeding using the lift pump a little valve in the regulating valve at the pump inlet moves to allow lift pump pressure to flood the whole of the pump body, and that includes the space under screw 5. It has to because it is pressure in that part that closes the governor valve if the engine speed gets higher than the throttle setting.

 

 

1 hour ago, marksbrown said:

The air bleed screw on the injection pump governor housing opened until the larger hex moves (but not much further) leads to a dripping off diesel with the lift pump.

 

This is worrying, it sounds as if you tried to take off the anti-stall damper adjusting bolt. The bleed screw is the small 8mm AF hexagon screwed into the top of the larger hexagon damper adjusting screw, and it should simply unscrew and come out without affecting the damper. Once you get it running, you should readjust that damper.

 

I have no idea why you get lost of fuel from the bleed screw on the side of the cylindrical pump body, but very little from the governor housing. In fact, I rarely ever touch that bleed screw, the one on the body normally does perfectly well.

 

The stop lever being stiffer suggests (no more than suggests) that the governor valve may be sticking so it is difficult to push down but from the history I can't see why, unless the period without running allowed some water in that valve to rust it. It may be stiffer (can't remember) if you try to operate it with the throttle still open, the throttle preloads a spring that the stop has to push against. it is, however, a very light spring.

 

Try this: Put the injector pipes back, and then loosen each by no more than one turn of the nut. Remove the return pipe between the pump connection closest to the engine block and the filter. Put the pipe back into the pump but turn it to direct any output into a container. Throttle fully open, stop right off, and spin on the stater while looking at the injector unions. If any drip, tighten them, but note that a lot of fuel will flow into the container. I don't feel 20 seconds of cranking is anywhere near enough to bleed the high pressure part of the system, but having the pipes off the injectors can make it harder to see when fuel is delivered.

[marksbrown]

I've attached the picture from the bmc 1.8 repair operation manual to clarify. Points 2 and 3 have been bled and tightened - no problems. Point 4, 6 has been unscrewed using the 8 mm which then after turning for a while opens the larger hex - I think you're saying I shouldn't have done that! I did however and bled until I get a steady drip from here. I then opened point 5 (leaving 4,6 open) and cranked the engine. Then I tightened point 4,6 - again cranked and tightened 5. Then I cranked with the four unions unscrewed. I've not touched either screws for min/max revs.

 

Quote

Try this: Put the injector pipes back, and then loosen each by no more than one turn of the nut. Remove the return pipe between the pump connection closest to the engine block and the filter. Put the pipe back into the pump but turn it to direct any output into a container. Throttle fully open, stop right off, and spin on the stater while looking at the injector unions. If any drip, tighten them, but note that a lot of fuel will flow into the container. I don't feel 20 seconds of cranking is anywhere near enough to bleed the high pressure part of the system, but having the pipes off the injectors can make it harder to see when fuel is delivered.

I'll try this now.

 

 

[Tony Brooks]

Thanks.

 

5 is an automotive adaption that does the same as loosening the injector nuts, but on one injector. You won't get much fuel out of here (one pinhead's worth per two revolutions). You should still be able to take the bleed screw right out without the actual union nut loosening, but you still won't get very much fuel out of it, even when spinning the engine. I would bleed the high pressure side from the large injector union nuts.

 

That bleed (5) is NOT on the governor housing, I suppose it is on the rotor head.

 

The governor housing is the casting under the parts 4,6. By all means, try bleeding from the small 8mm AF hexagon screw here. but please do not loosen the larger hexagons. It should deliver fuel just like form screw 3 when you use the priming leaver. On 3 and this screw, always keep priming for at least 30 seconds AFTER you think that you have all the air out.

 

When you crank the engine with all bleed screws and injector unions tight, how much "smoke" do you get from the exhaust. If it is more than a few wisps, then you may not be cranking fast enough or the glow plugs have stopped working. Try cranking while someone plays a blowlamp into the air intake (not if it is plastic or has a rubber/paper element).

 

If there is no smoke or t is really only a few wisps, then normally rebleeding the whole system, starting from the leak off banjo bolt on the filter you show in the diagram. I think that diagram is wrong because the leak back to the tank normally runs from that small banjo bolt as well.

 

Can you get the start battery charged?

 

[marksbrown]

With another boat's engine running, I've bled the fuel lines. Healthy amounts of fuel out of all four injectors. These were then tightened. Engine was started at full revs, half revs and idle. Each case the engine started increasing in revs almost immediately. Each time the boat stops with the stop lever immediately. I've checked range of motion on the throttle (to the point of removing the idle screw) to no effect. I've started the engine (and stopped) with the fuel cap off. The other boater has a compression testing kit, so I'm going to test the engine this afternoon.

[Tony Brooks]

34 minutes ago, marksbrown said:

With another boat's engine running, I've bled the fuel lines. Healthy amounts of fuel out of all four injectors. These were then tightened. Engine was started at full revs, half revs and idle. Each case the engine started increasing in revs almost immediately. Each time the boat stops with the stop lever immediately. I've checked range of motion on the throttle (to the point of removing the idle screw) to no effect. I've started the engine (and stopped) with the fuel cap off. The other boater has a compression testing kit, so I'm going to test the engine this afternoon.

 

It sounds like lack of fuel, those DPA pumps do rev up as transfer pump pressure falls, but I don't see how the gearbox work could cause this unless you have kinked a fuel pipe or knocked a fuel tap towards the off position.

 

I once heard a report of a 1.5 that did this (same pump as far as I know) and replacing the lift pump cured it, but this is just one and I can't explain it unless the lever on the camshaft is bent, that can't happen unless the pump is taken off.

 

As I think Johnk said, there is a fine strainer under the large hexagon nut where the fuel delivery pipe connects. Observing scrupulous cleanliness and using lint free rag, you could try taking that big nut off, but take care. there is a regulating valve and a couple of springs in there as well, don't let them jump out. I still don't see how the gearbox job could cause it to clog, unless t is just coincidence.

Edited March 3, 2023 by Tony Brooks

[marksbrown]

Mystery solved! So on my engine (for reasons unknown) the fuel goes from the tank to the lift pump *then* the water trap then the fuel filter prior to the injector pump. As you can see in the attached picture it was absolutely filthy. I've cleaned it out and I'll reattach to the engine at the weekend but given the symptoms this would be the smoking gun I believe. Is there a reason for this order of filters / pumps & would it make sense to re-jig the lines to go tank -> water trap -> fuel filter -> lift pump -> injection pump?

[Tony Brooks]

That is the way it is usually done BUT if the water trap is a CAV design it is all too easy to misassemble and suffer air leaks. That makes priming and running difficult to impossible. Doing it the way you frost described keeps most of the line under pressure, rather than having parts under suction.

 

I have seen worse, but was there a gauze filter under the cap? If so, how clean was that? Usually there were deep sediment traps around the middle part, there is a suggestion they are there on yours, so have a good dig around. The "Indian" pumps may not have a strainer.

[marksbrown]

The filter is in the picture. Below was full of brown gunk. The filter took a great deal of scrubbing to get clear. At the moment I'm struggling to reattach the fuel out screw true so I'm going to wait for better light on another day. Thanks again for your help.

[Tony Brooks]

17 minutes ago, marksbrown said:

The filter is in the picture. Below was full of brown gunk. The filter took a great deal of scrubbing to get clear. At the moment I'm struggling to reattach the fuel out screw true so I'm going to wait for better light on another day. Thanks again for your help.

 

I say "good" because it looks as if you may have cracked it. Cleaning that strainer SHOULD be a routine service job, but all too often is not, as you seem to have found.

[john.k]

In fact ,there should not be any contaminated fuel reaching the lift pump...........there should be a large plate strainer,primary filter  and water trap holding at least 1litre of water for daily draining...........the CAV water trap setup is little more than a toy,and nowhere near the size needed on a boat......Id nominate two likely problems with no fuel.......the white plastc inlet strainer on the pump clogged........and far worse ,the two little plungers in the hydraulic head stuck ......thse two plungers have no positive opening mechanism ,and if stuck will stay stuck until the pump is dismantled and they are pushed out of the head and the bore cleaned .

[marksbrown]

So after putting the lift pump back on - no change.I believe the lift pump is fine. If there is air getting in, I'm not sure how. I've bled through on the low pressure side and using a second boat's engine running, we're able to see fuel from all four injectors union nuts.

 

On the bright side, the compression test came back good. I'm inclined to believe I must have damaged the injection pump either by the abrupt stopping of the gearbox or during an attempt to bleed it. I will try taking off the inlet filter first, beyond that I think I'm at the point where it might just be easier to take the injection pump off and take to a reconditioners. 

[Tony Brooks]

Before you do that, try this. Look at the main fuel filter, where the return from the injector pump (the pipe nearest the block) connects to the filter. There should be an extra and longer hexagon "adapter" screwed in. This is an NRV so make sure it is not clogged. These can cause odd symptoms when they play up.

[StephenA]

5 hours ago, john.k said:

In fact ,there should not be any contaminated fuel reaching the lift pump...........there should be a large plate strainer,primary filter  and water trap holding at least 1litre of water for daily draining...........the CAV water trap setup is little more than a toy,and nowhere near the size needed on a boat......Id nominate two likely problems with no fuel.......the white plastc inlet strainer on the pump clogged........and far worse ,the two little plungers in the hydraulic head stuck ......thse two plungers have no positive opening mechanism ,and if stuck will stay stuck until the pump is dismantled and they are pushed out of the head and the bore cleaned .

 

If I was finding a litre of water a day in my canalboat fuel I'd be worried. We check our "toy" CAV a couple of times a season and its usually fine. We also check / pump the bottom of the main tanks from time to time.

[Tony Brooks]

16 minutes ago, StephenA said:

 

If I was finding a litre of water a day in my canalboat fuel I'd be worried. We check our "toy" CAV a couple of times a season and its usually fine. We also check / pump the bottom of the main tanks from time to time.

 

I agree, but remember that particular member is from Australia, so may have very little UK INLAND boating experience. I find a few of his pronouncements questionable.

[marksbrown]

Okay. I've replaced the o-ring on the lift pump screw, resat the water trap and fuel filters. I've checked for good flow of diesel on this section. I can get diesel to the injection pump and on cranking I can see equal amounts of diesel from all four union nuts on the injectors. I have bled the anti-damper screw and a great deal of air came out of here. I will definitely need to adjust the idle damper now and it seems loose and won't stay in one place regardless of the locking nut. Furthermore, I can see the oil level on the dip stick drops from mid to just below low when I do crank but returns to mid by the next day. From reading this forum it sounds like a seal on the rear of the crankshaft is gone and will need replacing but wouldn't be a reason for the over-revs on the engine.

 

Regardless of bleeding, I have been able to start the engine a dozen times, even in idle, even without heater plugs.

 

The NRV is a hex bolt with a tiny pin hole through it situated on the fuel filter and was not blocked. The banjo bolt through it has copper washes in between NRV, return pipe and bolt head.

 

I'm satisfied that the fuel line from tank to fuel filter is acceptable so I'm thinking the next step will be to carefully take out the inlet filter and check it for obstructions. If that doesn't solve it, I will try running a day tank to the injection pump.