Bleeding BMC!

[Mike Poole]

Just had a good run up to Llangollen with no problems with the old BMC 1.8 but coming through Audlem last night engine was ticking over/running erratically as if air in fuel system. This morning started up, ran for 10 seconds and it died. Bled to injector pump and with solenoid open diesel flowing out of bleed screw on pump body. However only a drop comes out of governor bleed screw and banjo screw and can't get anything out at injector unions. It did start up and run for 15 mins after I re-bled the return union on filter then it revved up and died again. Couldn't repeat the trick so I suspect coincidence. Any ideas much appreciated. I can think of worse places to be stranded but I'm back at work on Monday (Boo hoo).

[RLWP]

I know it's stating the obvious, but...

 

Have you turned the fuel tap on?

 

Richard

 

You can guess how I know about that one

Edited August 11, 2010 by RLWP

[Mike Poole]

Cheers Richard. Usually it is the obvious things or something I've messed with but this time I didn't touch a thing! Fuel is going through but not all the way.

Regards.

Mike

[koukouvagia]

I had very similar symptoms to this last year on a BMC 1.8. I was convinced it was a fuel problem – the engine began to run erratically then died. I could start it, but each time after a short while it conked out.

I bled the system (several times); checked and cleaned out the fuel pump; cleaned all the fuel lines, air filter and sucked out a couple of gallons of water from the bottom of the fuel tank. Still no luck. I even renewed part of the rubber fuel hose in case the inner lining was collapsing under suction. At this point I admitted defeat and called out an engineer. He did precisely the same as I'd done but in addition persuaded me to buy a new injection pump. Again, no joy. At this point the engineer also gave up. We towed the butty (which has a hydraulic motor driven by the BMC) back to base and called in another engineer (Ed Boden – highly recommended, but a bit too far from you) who found the problem: a blown cylinder head gasket.

[Mike Poole]

Holy Smoke! Never thought of that. Did you have any of the usual symptoms as well? I know it's far from foolproof but I can't see any water in the oil or vice versa. Thanks in the meantime. I'm off for another ponder.

[alan_fincher]

At this point the engineer also gave up. We towed the butty (which has a hydraulic motor driven by the BMC) back to base and called in another engineer (Ed Boden – highly recommended, but a bit too far from you) who found the problem: a blown cylinder head gasket.

But Mike says he is having trouble getting any fuel out at the injector unions when trying to bleed it ?

 

Interestingly though, I do recall something of the history of Mike's engine, which shares some similarities with that in Chalice, being installed in a boat, (I think it was Evans and son too ?), that has a very marginal skin tank system, and was (I think) prone to running hot.

 

I know that in the past Mike has had some suspicions about head gasket - for it was he that lent me a kit to test for leakage on ours!

 

Presumably though, with the issue you had on Hampton, bleeding the fuel system through would have produced fuel at all the expected places, which it sounds like is not happening for Mike ?

 

Mike - for reference although we found no head gasket issues when you lent the tester, last year the engineer that Koukouvagia refers to did diagnose head gasket issues. When the head came off, not only had the gasket been blowing at several places, the head was found to have cracks and loose core plugs, and had to be scrapped. It really is amazing how much abuse a BMC can take, and still appear to be running more or less OK !

[Mike Poole]

Hi Alan. Nice to hear rom you again. I think maybe I've been living on borrowed time re heads and gaskets according to what you say. Maybe the strain against the Llangollen flow proved too much. I'm still a bit puzzled about the lack of diesel at the injector end though. I've never fully bled it beore though so not sure what amounts too expect. At least some though!

All the best.

Mike

[alan_fincher]

I'm still a bit puzzled about the lack of diesel at the injector end though. I've never fully bled it beore though so not sure what amounts too expect. At least some though!

If you have cracked open the union between injector pipe and injector, you will get significant leakage of fuel if everything is OK.

 

By that I mean visibly dripping out.

 

If it isn't, I'd continue to concentrate on fuel, and only deviate to other issues if you can actually prove you have fuel at each injector, and it still will not keep running.

[raymac]

Hi I have in the past had problems bleeding my 1.8 bmc as well. After following the instuctions in the Austin Morris repair manual with no joy I removed the bleed screw on the high pressure banjo bolt on the injection pump (number 5 on the diagram ) while turning over the engine and it started it up straight away. I always had problems bleeding this engine and hope that I do not a head gasket gone after reading the other posts on this problem.

[Tony Brooks]

Just had a good run up to Llangollen with no problems with the old BMC 1.8 but coming through Audlem last night engine was ticking over/running erratically as if air in fuel system. This morning started up, ran for 10 seconds and it died. Bled to injector pump and with solenoid open diesel flowing out of bleed screw on pump body. However only a drop comes out of governor bleed screw and banjo screw and can't get anything out at injector unions. It did start up and run for 15 mins after I re-bled the return union on filter then it revved up and died again. Couldn't repeat the trick so I suspect coincidence. Any ideas much appreciated. I can think of worse places to be stranded but I'm back at work on Monday (Boo hoo).

 

 

Kill or cure time!

 

I assume you have checked the strainer (if there is one) under the lift pump cap AND made sure the cap & screw have good sealing washers/rings in place.

 

First I assume the talk about solenoid open means it has an electric stop solenoid which may be power to run or power to stop. The former engine just stops when you turn the "ignition" off whilst the latter requires you to press a button or turn the switch to a special position to stop. If the solenoid is one that screws into the pump I would remove it and spin the engine. I would expect loads of fuel to pour from the hole. If it does then you know fuel is getting into the body.

 

IF its an energise to run try starting/bleeding it with your finger over the hole. If it works the solenoid or its supply is faulty.

 

If not remove the feed pipe from filter to pump that is at the back of the pump and then unscrew the big hexagon with the union thread that is screwed into the endplate of the pump. Take care and be very clean, there is often a nylon strainer under there and I have known them to block. If blocked clean & bleed.

 

Put the whole lot back, set the throttle to full and loosen the injector union nuts. Remove the other "feed" (actually its a return) pipe between pump & filter from either end. Spin engine on starter of a while. Fuel should gush out. Put finger over hole/pipe end and continue with spinning on starter. You may like to loosen both the body (not the banjo) bleed screw and the governor one, take care with the governor one, I rarely used it. With the return blocked the transfer pump builds up pressure in the pump body and it often shifts some particularly abstinent bit of air. Once fuel is coming form the bleed screws close them and then the same as it drips from the injectors.

 

It will probably start as you tighten the injectors so take care.

[RobinJ]

Just had a good run up to Llangollen with no problems with the old BMC 1.8 but coming through Audlem last night engine was ticking over/running erratically as if air in fuel system. This morning started up, ran for 10 seconds and it died. Bled to injector pump and with solenoid open diesel flowing out of bleed screw on pump body. However only a drop comes out of governor bleed screw and banjo screw and can't get anything out at injector unions. It did start up and run for 15 mins after I re-bled the return union on filter then it revved up and died again. Couldn't repeat the trick so I suspect coincidence. Any ideas much appreciated. I can think of worse places to be stranded but I'm back at work on Monday

Its worth checking the attachments on the injector pump, I had a sudden failure a few years ago and it turned out to be one of the fittings (the front connection) becoming loose and letting air in.

A trick I often use to see if there are any air leaks is to turn off the return pipe if you can and use the lift pump, any air leaks show up as disel leaks!

As the engine was running erratically before it stopped, it is possibly not a fuel problem, could even be timing chain? Needs a systematic approach, whats easiest to check first?

[Mike Poole]

Thanks raymac, Tony and Robin for the latest thoughts. Having a bit of trouble replying due to signal. It's bad enough doing it on a phone with a dodgy 'f' key but I'll reply more fully ater I work through all the points. Cripes it's hammering down now.

[Mike Poole]

Crikey! Just working through Tony's steps starting at the lift pump and found (by touch) that that a copper coolant return pipe has been fouling the copper fuel pipe from lift pump to filter and worn it flat. I hoisted the coolant pipe out o the way and operated the lift pump. Fuel now pours out of pipe! I suspect it was on it's way yesterday and was worn enough to take in air but also not worn enough to prevent some priming to injector pump inlet. The reduced pressure may explain the lack of fuel at the governor bleed. Either way I can't carry on bleeding till it's fixed. The good news is that I haven't died in a blazing inferno and also that it may not be a duff gasket or injector pump! Does anyone know what size the pipe is from lift pump to filter and can it be bent by hand or is there a way o making a get me home connection? If not I'll have to call in the professionals.

Cheers

Mike

[Tony Brooks]

Crikey! Just working through Tony's steps starting at the lift pump and found (by touch) that that a copper coolant return pipe has been fouling the copper fuel pipe from lift pump to filter and worn it flat. I hoisted the coolant pipe out o the way and operated the lift pump. Fuel now pours out of pipe! I suspect it was on it's way yesterday and was worn enough to take in air but also not worn enough to prevent some priming to injector pump inlet. The reduced pressure may explain the lack of fuel at the governor bleed. Either way I can't carry on bleeding till it's fixed. The good news is that I haven't died in a blazing inferno and also that it may not be a duff gasket or injector pump! Does anyone know what size the pipe is from lift pump to filter and can it be bent by hand or is there a way o making a get me home connection? If not I'll have to call in the professionals.

Cheers

Mike

 

 

Personally I would take the pipe off and see if a local boatyard/body shop could be persuaded to stick a bit of silver solder over the damage for a folding beer token.

 

If you do not have a banjo on the lift pump end I think a length of copper pipe and a couple of new olives will sort it for you (boatyard of chandlers).

 

For a quick DIY "get you home" bodge I reckon clean the pipe up with a bit of white spirit or thinners and then wrap in Duct tape, gaffer tape, insulating tape (given time the diesel may effect the glue on these) or some of the self amalgamating rubbery type tape that has recently appeared. I think chandlers and B&Q sell it. You cold also try some of the "snap a bit off & knead" "putty" over the damage.

 

Its on the pressure side and there is a filter between the damage and the injector pump so you are unlikely to do even more damage.

[paulcatchpole]

Personally I would take the pipe off and see if a local boatyard/body shop could be persuaded to stick a bit of silver solder over the damage for a folding beer token.

 

If you do not have a banjo on the lift pump end I think a length of copper pipe and a couple of new olives will sort it for you (boatyard of chandlers).

...

 

The lister's pipes have generally been 3/16", and a 3/16" compression coupler might get you out of trouble (measure it and see), or Tony's suggestions are good as well. I wonder if stretchy tape wouldn't help with the bleeding issue, but I'm not sure... Chemical metal or the putty variant would be worth a go, but get it good and clean with some emery and some thinners or carb/brake cleaner, first.

 

PC

[sultan]

Crikey! Just working through Tony's steps starting at the lift pump and found (by touch) that that a copper coolant return pipe has been fouling the copper fuel pipe from lift pump to filter and worn it flat. I hoisted the coolant pipe out o the way and operated the lift pump. Fuel now pours out of pipe! I suspect it was on it's way yesterday and was worn enough to take in air but also not worn enough to prevent some priming to injector pump inlet. The reduced pressure may explain the lack of fuel at the governor bleed. Either way I can't carry on bleeding till it's fixed. The good news is that I haven't died in a blazing inferno and also that it may not be a duff gasket or injector pump! Does anyone know what size the pipe is from lift pump to filter and can it be bent by hand or is there a way o making a get me home connection? If not I'll have to call in the professionals.

Cheers

Mike

Hi Mike

Had a similar frayed pipe some time ago. Remove entire pipe from lift pump and filter, It will probably have nuts and olives at each end .Take it all to a general repairs garage or better still, an agricultural egineers. They will likely be able to make one up. There are still some Leyland tractors operating around Audlem and some have a BMC engine that wears the same lift pump so pipe to fit should be available. A pipe a bit longer is no problem because you can always bend a curve to make it fit. Failing this to get you home cut the bad bit out of the pipe and join using a short length of flexible fuel pipe and jubilee clips. You should be able to get this from any motor factors. IMPORTANT Make sure it is FUEL pipe,is a good fit on the clean metal pipes and route well away from the exhaust.

Good luck

Sultan

[Mike Poole]

Thanks again all. Sultan I did find some car fuel pipe on board so did just what you said - took pipe off cut out bad bit and used fuel pipe clips to link in the hose. I worked through Tony's list and although fuel gushed out of bleed screw on pump body there was still only a dribble at the governor bleed and injectors. Still it started up and ran fine for about 15 mins then it revved up and diied. Did same thing three times but ran for less each time and now I stink of diesel diesel. Had to give up while I charge battery with genny. I'm pretty sure I've checked every joiint though.

Cheers

Mike

[RobinJ]

Thanks again all. Sultan I did find some car fuel pipe on board so did just what you said - took pipe off cut out bad bit and used fuel pipe clips to link in the hose. I worked through Tony's list and although fuel gushed out of bleed screw on pump body there was still only a dribble at the governor bleed and injectors. Still it started up and ran fine for about 15 mins then it revved up and diied. Did same thing three times but ran for less each time and now I stink of diesel diesel. Had to give up while I charge battery with genny. I'm pretty sure I've checked every joiint though.

If you have any fuel free rags left, clean up the pipes and fittings so they feel dry, pump the lift pump and check to see if there is any fuel running out of joints or along any pipes.

Bear in mind 15mins running represents about 150ml which is not a lot of air!

If you get depserate and have a container, you can put fuel into it and drop each pipe in turn until you get to one that leaks!

Provided air is causing the problem, it is most likely to be on the injector pump side of the fuel filter, also have you checked the return pipes?

[Tony Brooks]

Thanks again all. Sultan I did find some car fuel pipe on board so did just what you said - took pipe off cut out bad bit and used fuel pipe clips to link in the hose. I worked through Tony's list and although fuel gushed out of bleed screw on pump body there was still only a dribble at the governor bleed and injectors. Still it started up and ran fine for about 15 mins then it revved up and diied. Did same thing three times but ran for less each time and now I stink of diesel diesel. Had to give up while I charge battery with genny. I'm pretty sure I've checked every joiint though.

Cheers

Mike

 

 

The rev up is a good indication of fuel starvation. It sounds as if it is sucking air into the system somewhere. Have you changed the filter recently? If so go back and check all the rubbers seals. Take great care with the bolt that holds the lot together because some have a soft washer under their head and some use a small O ring. If the hole the bolt fits into has a small taper on top it uses an O ring (supplied with the new filters) but I would still put a nylon washer on there as well.

 

Have you checked your fuel level? It does get stolen now and again and I assume you made sure the fuel tap is turned on.

 

From anywhere on the tank side of the lift pump try blowing back into the tank in case the inlet in the tank is blocked. Remember to turn the tap off before undoing the connection. If you can not then get a car's spare wheel blown up to the maximum allowed on the sidewall. and a length of hose bodged suitably to allow you to clip it to the pipe you took off and the other end go over the tyre valve. Take out the valve core and quickly push the hose over the valve,. If that does not shift the blockage it will demand the pipes removing and checking until you find the blockage.

 

If your fuel supply pipe comes from the top of the tank it is even possible that the dip tube in the tank has cracked. It may be worth rigging a small gravity test tank to the filter inlet so you rule out the lift pump, tank & pipes.

 

I had a correspondent in Holland who had similar problems and he found an O ring associated with the valve that is under that big hexagon I mentioned in my last post was damaged, but it is the only instance I have come across and suspect it was done by a previous owner.

 

I wish you would stop messing about with that governor bleed screw and just use the one on the pump body. On many DPA pumps that bleed screw is part of the idle stabilisation valve and I have seen too many messed up by the owners bleeding there.

[larkshall]

I would wonder about the lift pump.

 

A) has diaphragm stretched, or got a hole.

Valves have they worn and given up the ghost?

c) Has the pump heel to camshaft worn badly...

 

As you can manually pump fuel, my money is on c... (The mechanical actuator hasn't ot the same dgree of lift

[Tony Brooks]

I would wonder about the lift pump.

 

A) has diaphragm stretched, or got a hole.

Valves have they worn and given up the ghost?

c) Has the pump heel to camshaft worn badly...

 

As you can manually pump fuel, my money is on c... (The mechanical actuator hasn't ot the same dgree of lift

 

 

I would tend to agree with you except he said that had already followed my check list and two of those checks should have indicated the lift pump delivery whilst cranking.

 

We also had a similar set of symptoms on here a while ago and it turned out to be that little O ring on the filter if I remember correctly.

[Albion]

Tony said (snipped)

We also had a similar set of symptoms on here a while ago and it turned out to be that little O ring on the filter if I remember correctly.

 

I agree. A friend of mine had identical symptoms, also at about 15 min intervals, on a JP3. It turned out, after much searching, to be an inadequate seal on the small O ring under the head of the filter securing through-bolt. The ring seems to seal in that it feels OK when you're tightening the bolt but fails to seal adequately. The solution was to put a heavier section O ring in place and to avoid over-tightening as this was also distorting the shape of the earlier light section one. The O rings supplied with many of the pattern filters are very similar and of the light section version IMO.

Roger

Edited August 13, 2010 by Albion

[Mike Poole]

I would wonder about the lift pump.

 

A) has diaphragm stretched, or got a hole.

Valves have they worn and given up the ghost?

c) Has the pump heel to camshaft worn badly...

 

As you can manually pump fuel, my money is on c... (The mechanical actuator hasn't ot the same dgree of lift

[Mike Poole]

Ignore last post. This Opera mini on the phone has a mind of it's own!

Thanks for the continued thoughts. Tony, I've stopped messing with the governor screw. I found that for each attempt about a filters worth of fuel is used. When the engine stops just bleeding through using screw no 5 on the pump body using the lift pump (new last year) then cracking the injector unions and cranking does the trick. I didn't do anything until late today due to diesel madness but I've replaced the fuel filter as a precaution. blown through the return hose. took off and blown through the steel return rail (which had some grot in part of it) all to no avail. A few minutes running then stop. (When it's running it runs well until it runs out!) When running there seems plenty of diesel getting to the injector pump (but this could be the filter contents) but nothing coming along the steel return rail. Will recheck this again tomorrow and to re-confirm lift pump is deliivering 'on the crank'. It probably doesn't matter but does the return pipe sit in diesel in the tank or is it shorter than the feed? Again I don't know If it makes a difference but I don't think I've ran my tank below half full in years.It 's about a third full now and there was no resistance to blowing through the return pipe.

Cheers

Mike

[Tony Brooks]

Ignore last post. This Opera mini on the phone has a mind of it's own!

Thanks for the continued thoughts. Tony, I've stopped messing with the governor screw. I found that for each attempt about a filters worth of fuel is used. When the engine stops just bleeding through using screw no 5 on the pump body using the lift pump (new last year) then cracking the injector unions and cranking does the trick. I didn't do anything until late today due to diesel madness but I've replaced the fuel filter as a precaution. blown through the return hose. took off and blown through the steel return rail (which had some grot in part of it) all to no avail. A few minutes running then stop. (When it's running it runs well until it runs out!) When running there seems plenty of diesel getting to the injector pump (but this could be the filter contents) but nothing coming along the steel return rail. Will recheck this again tomorrow and to re-confirm lift pump is deliivering 'on the crank'. It probably doesn't matter but does the return pipe sit in diesel in the tank or is it shorter than the feed? Again I don't know If it makes a difference but I don't think I've ran my tank below half full in years.It 's about a third full now and there was no resistance to blowing through the return pipe.

Cheers

Mike

 

The return pipe normally just goes into the top of the tank but I can see no harm in it if it dipped into the fuel.

 

I do not have a BMC manual (and yours may not be the actual BMC one) so identifying the bleed screw by diagram number is not much help, but as long as it is the one on the cylindrical cast alloy body its the one to use.

 

I am assuming your "return rail" & "hose" refers to the injector bleed off pipe and not the return from injector pump to filter. That one is the pipe that runs from the front of the pump to the filter connection with the inwards arrow cast on the filter head. Fuel should pour out of that return with the engine running and if it does not the lift pump is suspect.

 

If the injectors are in fair condition very little fuel should flow back from them BUT the banjo bolt that holds the rail to the filter head should be hollow with a 0.5mm hole drilled through one side of it. This is to allow any air that has found its way into the system to rise up in the filter and return to the tank before it has a chance to pass in to the injector pump and stop the engine. Fuel should not gush from the return but it should have a steady trickle.

 

Your symptoms are consistent with that 0.5mm hole being blocked so check it. If it is blocked or if a clown has replaced the bolt with an ordinary solid bolt drill it out using a very small drill.