BMC complicated question

[dr pepper]

I have a bmc 1.5 captain, which ran fine until the head gasket failed, I replaced the gasket and torqued up all the bolts properly, and I cleaned out the chambers will a drill bit as suggested in the book, but upon reassembly the engine is difficult to start (even with new heaters) and every so often misses and blows out grey smoke, this to me sounds like a sticking injector.

Anyway I have got 3 brand new cav injectors off ebay for 7.50, they look exactly the same as the originals but I was wondering if anyone knows the correct number of injector for the 1.5, the originals are all unreadable, the new ones are BKB35 SD5260 PV IDES No.490608, the castings I believe are the same for the 1.5,1.8,2.2 and 2.5 however the springs and needles probably are not.

[rover220]

I have a bmc 1.5 captain, which ran fine until the head gasket failed, I replaced the gasket and torqued up all the bolts properly, and I cleaned out the chambers will a drill bit as suggested in the book, but upon reassembly the engine is difficult to start (even with new heaters) and every so often misses and blows out grey smoke, this to me sounds like a sticking injector.

Anyway I have got 3 brand new cav injectors off ebay for 7.50, they look exactly the same as the originals but I was wondering if anyone knows the correct number of injector for the 1.5, the originals are all unreadable, the new ones are BKB35 SD5260 PV IDES No.490608, the castings I believe are the same for the 1.5,1.8,2.2 and 2.5 however the springs and needles probably are not.

 

has the pump timing been touched? id be leaning towards this being the fault.

Edited October 7, 2008 by rover220

[dr pepper]

Nope I never touched the pump, the engine was running well before the gasket failed.

Does seem odd that an injector or something would fail upon re-build, its likely something I did to it while it was apart, maybe I caught the end of one of the inectors on dissassembly.

[RobinJ]

I have a bmc 1.5 captain, which ran fine until the head gasket failed, I replaced the gasket and torqued up all the bolts properly, and I cleaned out the chambers will a drill bit as suggested in the book, but upon reassembly the engine is difficult to start (even with new heaters) and every so often misses and blows out grey smoke, this to me sounds like a sticking injector.

Anyway I have got 3 brand new cav injectors off ebay for 7.50, they look exactly the same as the originals but I was wondering if anyone knows the correct number of injector for the 1.5, the originals are all unreadable, the new ones are BKB35 SD5260 PV IDES No.490608, the castings I believe are the same for the 1.5,1.8,2.2 and 2.5 however the springs and needles probably are not.

The originals are quoted as -35-SD5188, I don't know the significance of the numbers?

I would be tempted to check the valves, clearances and take a peak at the condition of the timing chain, it could be an injector problem, sticking valve or a worn chain, any of which could affect the firing or timing.

It might also be worth checking nothing else has worked loose e.g. the pump.

[Tony Brooks]

I have a bmc 1.5 captain, which ran fine until the head gasket failed, I replaced the gasket and torqued up all the bolts properly, and I cleaned out the chambers will a drill bit as suggested in the book, but upon reassembly the engine is difficult to start (even with new heaters) and every so often misses and blows out grey smoke, this to me sounds like a sticking injector.

Anyway I have got 3 brand new cav injectors off ebay for 7.50, they look exactly the same as the originals but I was wondering if anyone knows the correct number of injector for the 1.5, the originals are all unreadable, the new ones are BKB35 SD5260 PV IDES No.490608, the castings I believe are the same for the 1.5,1.8,2.2 and 2.5 however the springs and needles probably are not.

 

 

The 1.5 uses a pintaux injectors but there are loads of superficially similar pintle injectors around. Even if you have managed to get hold of pintle injectors the problem is likely to be more in the starting department than running.

 

You can tell the difference if you look very carefully at the nozzle. The pintle ones are flat with the small pintle on the needle sticking out. Pintaux have a sort of mound around the pintle with a small hole drilled on one side of it.

[dr pepper]

I was thinking about that when I got them, yes they are pintaux and there is an auxialliary jet.

 

I decoked the head when it was off, and also ground in the valves, and fitted new oil seals, the valves and guides all looked in good nick.

 

I'm wondering if I got a piece of junk or old paint flakes thats there was lots about in one of the injector pipes and wrecked the injector.

There was no sign of trouble before, messing with the injector pipes wouldnt move the pump, would it, I'll check the timing marks on the pump next time I'm aboard.

 

At the same time as doing the gasket I fitted another alternator, but I've tried the engine with the original belt, missing out the new alty and its still runs like a bag of bolts.

 

Robin j, looking at your numbers, it looks like there is a difference 5260 on mine and 5188 on yours, I wonder if thats flow rate or something, I'll try and find what the numbers mean.

 

Thanks for the help chaps.

Edited October 8, 2008 by dr pepper

[dr pepper]

Well I can confirm that the BKB35 SD5260 do not fit, completely diffo.

[John Orentas]

Well I can confirm that the BKB35 SD5260 do not fit, completely diffo.

 

 

Hi Doc.

 

It certainly sounds like a problem with the injector timing, the timing marks will not help you much at all, the problem centres on the fact that your engine was derived from a petrol engine in the distant past, the drive system that connects to your injector pump is that which originally had only to drive the distributer on the petrol engine, it isn't really up to the job so consequently it suffers from a lot of wear and eventually results in considerable backlash.

 

To adjust the timing you need to loosen the three fixing bolts and rotate the pump the opposite way to the running direction of the engine. Not a 'feeler gauge job' this, start by rotating the pump as far as the slots will allow, but you may well end up filling out those slots to permit even greater movement.

 

The trial and error method is the best way to find the optimum position, you should be rewarded by a vast improvement of the running of your engine.

Edited October 13, 2008 by John Orentas

[RobinJ]

I'm wondering if I got a piece of junk or old paint flakes thats there was lots about in one of the injector pipes and wrecked the injector.

There was no sign of trouble before, messing with the injector pipes wouldnt move the pump, would it, I'll check the timing marks on the pump next time I'm aboard.

Just a thought, did you put new sprung washers in with the injectors, if so, did you remove all the old ones?

Same could apply to the copper washers, have you crushed one or got two stacked up?

[larkshall]

Just a couple of questions

 

When doing decoke, did you check that the pushrods were true?

 

Did you check the head for being true?

 

Did You check the rocker shaft and rockers had no excessive play.

 

I ask coz years ago, I managed to bend a pushrod when re-fitting head, caused all sorts of weird symptoms.

 

As for the dizzy/fuel pump drive, you can check for wear by removing pump, and check how much backlash you are getting by inserting screwdriver, and seeing how much play you have in either direction.

[dr pepper]

no I did not check that the rods were true, the gaps were all pretty close when I put the head back on though.

I skimmed the head in the bridgeport here, only by .001".

I didnt check the rocker shaft, or rockers.

I have not checked the backlash on the pump.

I did check the cam followers, there was some witness marks on the cam surface, but not excessive.

 

Things seem a little odd as the problem only occurred after I messed with the engine, so it kinda looks like its something that I have done to mess things up.

I will next week remove the rockers and push rods, I can check the pushrods and rocker shaft in the lathe, checking these is a good idea, as I could have screwed up here.

as for the pump, I cant think why that would go wrong, unless its co-incidence, however the thing could do with a clean out, so I might just have the thing out and cleaned and check the backlash.

I did check the oil jet and filter at the other side of the block to the pump, and they were fine.

[Guest TerryL]

no I did not check that the rods were true, the gaps were all pretty close when I put the head back on though.

I skimmed the head in the bridgeport here, only by .001".

I didnt check the rocker shaft, or rockers.

I have not checked the backlash on the pump.

I did check the cam followers, there was some witness marks on the cam surface, but not excessive.

 

Things seem a little odd as the problem only occurred after I messed with the engine, so it kinda looks like its something that I have done to mess things up.

I will next week remove the rockers and push rods, I can check the pushrods and rocker shaft in the lathe, checking these is a good idea, as I could have screwed up here.

as for the pump, I cant think why that would go wrong, unless its co-incidence, however the thing could do with a clean out, so I might just have the thing out and cleaned and check the backlash.

I did check the oil jet and filter at the other side of the block to the pump, and they were fine.

 

If you ground the valves then you must readjust the tappets, you don't appear to have done that. They could be well out of adjustment and not closing properly especially if you've mixed them up or the valves and stems have still got grinding paste on them.

[LEO]

If you ground the valves then you must readjust the tappets, you don't appear to have done that. They could be well out of adjustment and not closing properly especially if you've mixed them up or the valves and stems have still got grinding paste on them.

 

Hi,

 

I found that you have to re-adjust the tappets on a BMC 1.5 as part of the re-assembly proceedure, due to the design of the rocker shaft and position of the head nuts. OP - are you sure there are no cracks in cylinder head? - I have heard that BMC cylinder heads are prone to this problem.

 

Albion

[dr pepper]

Well not quite that bad, I did adjust the tapets after re-assembly, before first run, and after cool down, and I did back the adjusters off all the way before diss-assembly (I measured the height of the adjusters with calipers first so I would now how much different they'd be on re-assy as a guide, and they are very close), I might have got a rod trapped on reassembly though, so its worth checking.

I spent an hour cleaning off grinding paste and used an air-line and trike (yep I know its banned) so I dont think thats a problem.

There could be a crack in the head, thats possible, I'm not getting pressure in the water jacket like I was before the gasket change, and engine temp seems ok.

Think I'd better check the rocker shaft and the pump drive, thanks for the advice, I'm alone on this one.

Hi Leo, whats 'Albion', wouldnt be albion automotive would it?.

Edited October 14, 2008 by dr pepper

[Guest TerryL]

Well not quite that bad, I did adjust the tapets after re-assembly, before first run, and after cool down, and I did back the adjusters off all the way before diss-assembly (I measured the height of the adjusters with calipers first so I would now how much different they'd be on re-assy as a guide, and they are very close), I might have got a rod trapped on reassembly though, so its worth checking.

I spent an hour cleaning off grinding paste and used an air-line and trike (yep I know its banned) so I dont think thats a problem.

There could be a crack in the head, thats possible, I'm not getting pressure in the water jacket like I was before the gasket change, and engine temp seems ok.

Think I'd better check the rocker shaft and the pump drive, thanks for the advice, I'm alone on this one.

 

In my experience sticking valves are common after a regrind no matter how well they're cleaned and can take a little while to settledown again. Obviously correct valve gap adjustment at the right positions is important for them to close fully at the right time and a bent pushrod would increase the gap but still work ok if readjusted, unless really bad. I'd check it over again including valve adjustments to the book method to be sure, then run it and see if it settles down. Where can you still get trike?

[dr pepper]

Yep ok thanks for the advice terry, thats re-assuring and makes sense, I will take the rocker shaft out and pushers and check things out, what would you say maximum runout would be 1mm?.

 

We use spray 'trike' here a lot, we are a paper converters, so we dont use sticky solvents.

The stuff we have is called 'TF 90', and its made by:

Action Can LTD.

Dixon close

Merseyside

01942 713667

It says its a Trichloroethene replacement, but it works like and smells just the same, incredible stuff, just squirting it on shifts nearly anything, half a can got the head like new, we use loads of the stuff.

[bag 'o' bones]

On the subject of injectors getting them pop tested is a good move before re-fitting.

 

Basically its a hand operated pump that tests the spray pattern and at what pressure the injector spring releases. If an injector works perfectly on the bench then there is no reason why it shouldn't when refitted.

 

Testing even new injectors is always good practice at it rules them out if a starting/running problem crops up.

[dr pepper]

yeah that would be a good idea, I was trying to avoid the expense, as our local place has gone silly with prices, but I spose its getting to the point where that would be a good idea, if I take em out again, then I'll do just that.

 

You know I saw one of those hand pump gizmo's on fleabay, and it went for peanuts, but you never think when you need to do you.

[Guest TerryL]

yeah that would be a good idea, I was trying to avoid the expense, as our local place has gone silly with prices, but I spose its getting to the point where that would be a good idea, if I take em out again, then I'll do just that.

 

You know I saw one of those hand pump gizmo's on fleabay, and it went for peanuts, but you never think when you need to do you.

 

If you can reconnect the injector pipes after taking them out you can test the spray pattern by spinning the engine over but be careful of the spray as it can penetrate the skin! Thanks for the trike info.

[dr pepper]

I was a bit scared of doing that, with the pressures involved, it is dangerous.

I saw a video earlier of a bolinger engine running on you tube, linked from this site, that took me to another site which had an inector in a washing up bottle as a safety guard, so I think I will try that and see what happens.

I'm assuming that I should get 2 spray patterns, one from the pintle and one from the auxilliary jet, and presumably cone shaped, has anyone else tried this?.

[John Orentas]

It is completely non-productive messing about with injector spray patterns, you will never know when it is correct, you will never know when it is wrong and there is a small element of danger, so why bother.. Anyway spray patterns never will be so far out of spec. that they will stop your engine running..

 

In all my years of dealing with diesel engines I have never had reason to repair or replace an injector, they so very rarely go wrong and when they do it is usually because someone has been fiddling with them.

 

Ignore all those books that tell you to take them out periodically.

[Guest TerryL]

It is completely non-productive messing about with injector spray patterns, you will never know when it is correct, you will never know when it is wrong and there is a small element of danger, so why bother.. Anyway spray patterns never will be so far out of spec. that they will stop your engine running..

 

In all my years of dealing with diesel engines I have never had reason to repair or replace an injector, they so very rarely go wrong and when they do it is usually because someone has been fiddling with them.

 

Ignore all those books that tell you to take them out periodically.

 

I'd have to agree with that I've never had to change injectors or pump either but some people are going to fiddle regardless so might as well tell them an easy way so they can get it done and onto the real problem. The never follow the advice until everything else but the advice has been tried!

 

Aren't we supposed to be joined at the hip or something?

[David Schweizer]

It is completely non-productive messing about with injector spray patterns, you will never know when it is correct, you will never know when it is wrong and there is a small element of danger, so why bother.. Anyway spray patterns never will be so far out of spec. that they will stop your engine running..

 

In all my years of dealing with diesel engines I have never had reason to repair or replace an injector, they so very rarely go wrong and when they do it is usually because someone has been fiddling with them.

 

Ignore all those books that tell you to take them out periodically.

Haven't fiddled with mine in ten years - Injectors that is.

[Tony Brooks]

It is completely non-productive messing about with injector spray patterns, you will never know when it is correct, you will never know when it is wrong and there is a small element of danger, so why bother.. Anyway spray patterns never will be so far out of spec. that they will stop your engine running..

 

In all my years of dealing with diesel engines I have never had reason to repair or replace an injector, they so very rarely go wrong and when they do it is usually because someone has been fiddling with them.

 

Ignore all those books that tell you to take them out periodically.

 

 

I can only agree with this up to a point. There is absolutely no point in ordinary boaters fiddling with injectors, but if they are suffering from poor cold starting, smoke and/or rough/noisy running (not forgetting misfires) I can see no reason a boater should not take them out and deliver them to a specialist - as long as they have the manual for checking on seal/atomisation washer locations etc.

 

When I bought the boat it had done 9 years in hire fleets and what I subsequently found leads me to believe the injectors had never been out. On the first trip the engine misfired for several minutes. As soon a is could I took the injectors out and had our local specialist check them. His description of the spray pattern, back leakage and dribble should not be repeated in polite company.

 

Injectors do need attention but the average owner can do nothing to improve them and will probably do far more harm. Also I get the impression that the modern pintle injectors tend to self clean but if you have multi-hole nozzles they might need more regular attention.

[rover220]

ive had a set of bmc 1.5 injectors that had such a poor, varied spray pattern that the engine would barely run.