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Post by tommydp on Aug 19, 2011 13:44:55 GMT
Yep, I'm a teacher, but afraid we don't have a scope available. I believe too, the first thing is to rule out electrics/ ignition which I suspect the most (again...) I'll contact some garages, and hopefully find some older diagnostic tools and mechanics:-)
Alex, A good question, and I understand your point. It will now be easier to look at items that have not been changed:-) The fuel tank and steel supply pipe has not been changed. The alternator and fuel pump has not been changed lately. Otherwise, except the crank and pistons, lol, I think I've tried substituting everything numerous times:-)
Regards, Tommy:-)
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Post by tommydp on Aug 28, 2011 21:43:57 GMT
About time for an update I suppose! Sadly there's not been any positive progress. I've driven it quite a lot, but the symptoms remain. I've not been in the mood for investigating further to be honest:-) School has started again, so I have to concentrate on the pupils too, of course:-) Further, I've had to work on the modern Peugeot's brakes as well as the school's IVECO minibus which has a dodgy starter and universal joint, gobbles fan belts and lets water in virtually everywhere.. OMG, in my next life I'll collect stamps:-)
So, the Crab is still the same unfortunately. My uncle will have a look at it, so I'm looking forward to that. He's an old school mechanic and has worked on just about everything when it comes to engines. He even worked at the BL dealer here in the late sixties. Hopefully someone else having a look, will sort things out.. Just too bad I haven't been able to solve it myself:-)
After all the headaches with this car I've come to the conclusion that:
1. I'm doing something wrong when it comes to putting the engines together, the symptoms have remained with different engines.. I just can't see what I could be doing wrong though..
OR
2. There is something wrong with the car itself beyond the engine, distributor, carb etc. Wiring, charging circuit, ignition circuit, earth trouble, fuel supply (tank, steel pipe) etc.
I really suspect nr 2, as the trouble has remained all the time since I got it running again, and with 3- three!- engines, including a rebuilt one..
My only clues are:
- all coils still get's abnormally hot at idle, even with 45 d dizzy and dwell of around 50 %.
- fuel filter is sometimes almost full, sometimes almost empty. Sometimes a pulse can be felt on the hose between pump and carb, sometimes not.
- different Lucas acr alternators, including rebuilt one, make in my opinion abnormal noise, whining. This does not occur when using these on the other crab. Charging lamp does not light up when driving- But I have to rev it to make it go out when starting. Charging at fast idle and above is fine.
- cylinders 2, 3 and 4 are now dry after running, and also after long period of idle. Dry sooth on pistons, plugs bisquit brown. Number one is still wet, especially after long idle. This appears to me as unburned oil, like the oil on the dipstick. There's no smoke when idling.
- I've tried a Gunson flash test on it, and the HT is well within the green area.
- It's suddenly become occasionally difficult to start when hot. Not firing instantly as it usually does. I need to keep the accelerator in a bit to fire when hot. Never had to do that on crabs before.
- There's a puff of black smoke when revving it.
- It's been converted to negative earth, and used to have an 11 AC alternator with separate regulator and field isolating relay and warning light relay. I've converted others without problems. The other crab has had the same conversion, and everything looks identical.
Well, enough for now! I'm really looking forward to having it out of sight, and into my uncle's garage:-)
Regards, Tommy:-)
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Post by dave1800 on Aug 29, 2011 2:58:47 GMT
Hi Tommy
Glad to see you have retained your sense of humour! Hopefully a fresh pair of eyes will get to the bottom of the issue(s); it has just got to be something simple.
Your alternator definitely sounds dodgy if you have to rev it up on starting to get the light to go out, no idea why they whine on this but not the other cars - belt alignment maybe?
The hot starting problem is probably due to too rich a mixture (hence your black smoke) or a vapour lock, have you checked the pipe routing and carb insulation block?
Your coil heating defies the basic laws of physics.
Did you ever try disconnecting the alternator plug and run the car on the battery for a short time to see if the alternator and conversion electrics are doing anything peculiar to the ignition? I once had an alternator do very strange things to the headlights.
The one cylinder getting oily needs further investigation to see if it is the head (valve guides) or head gasket - do a compression test - and see if it is enough to cause a misfire.
Hope your uncle has your patience! But never say you are happy to see your Crab go away!
Regards
David
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Post by tommydp on Aug 30, 2011 20:48:42 GMT
Hi Tommy Glad to see you have retained your sense of humour! Hopefully a fresh pair of eyes will get to the bottom of the issue(s); it has just got to be something simple. Your alternator definitely sounds dodgy if you have to rev it up on starting to get the light to go out, no idea why they whine on this but not the other cars - belt alignment maybe? The hot starting problem is probably due to too rich a mixture (hence your black smoke) or a vapour lock, have you checked the pipe routing and carb insulation block? Your coil heating defies the basic laws of physics. Did you ever try disconnecting the alternator plug and run the car on the battery for a short time to see if the alternator and conversion electrics are doing anything peculiar to the ignition? I once had an alternator do very strange things to the headlights. The one cylinder getting oily needs further investigation to see if it is the head (valve guides) or head gasket - do a compression test - and see if it is enough to cause a misfire. Hope your uncle has your patience! But never say you are happy to see your Crab go away! Regards David Hi, Dave! Yes, my sense of humour is still present! A sense of humour is really an advantage when working on stubborn cars as well as when meeting other challenges:-) I've spent the evenings with the IVECO, so not done any more to the Crab. I think I'll leave it now until my uncle has time for it. Amazing how busy older people are these days:-) Well, he's retired and runs a"private" garage and has plenty to do. Hope to get it there within a week or so. Speaking of the IVECO, have anyone tried to change the starter on a generation 2 35-10 Turbo Daily? Holy cow, what a job! Seriously, you can't even see the starter before removing the exhaust system, various shields etc. And it's quite awkward to reach it and its bolts. All has to be done from the underside too, you'll never reach it standing over the engine compartment. Looking forward to get the new one installed and working and avoid the frequent complaints about slow cranking! It's quite challenging to be responsible for a battered car used by lots of different people daily! Regarding the crab, and your reply David: Pipe routing fine, and carb insulator block ok. I've even installed a large heat shield between manifold and carb from the Princess. I suspect the alternator, or rather something causing the alternator(s) to play up. Belt alignment is spot on. Even a reconditioned one behaved strangely, headlights flickering, intermittent whining. Had it checked, and it was all fine. They believed something in the car was playing it up. He explained something like a load occuring, putting strain on the alternator. The present alternator whines too, especially when the headlights are on. It's like an internal whine, not like from the belt. Actually, I don't notice a difference to the engine when I remove the alternator plug. Lights brighten up when revving from idle, but don't flicker. Regarding compression I haven't checked it lately, but believe they were all spot on 180 last time I checked. I'll have a look again. Regards, Tommy:-) |
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Post by kelsham on Aug 31, 2011 7:36:50 GMT
Hi Tommy, If you have the tappets set too tight in an effort to quieten the valve gear it is possible that when warmed up the valves will remain open.
After I had my valve seats changed to run unleaded petrol I fell into this trap.
I felt that all was not well after the engine got hot, and used a compression tester, when to my horror I had low compression on two cylinders. Opening the tappet gaps cured the problem.
I am sure you know this but I thought my experience might be of interest. As I recall I was using just slightly tight clearances.
Regards Kels.
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Post by tommydp on Sept 1, 2011 6:27:20 GMT
Thanks! All replies are welcome! I'm sure I set the valves too tight earlier, but now the are fine. Not too tight at least.
I checked the compression yesterday. It's 180 on all cylinders, perhaps a tiny bit less on cylinder one, but it's between 175 and 180.
My uncle had a first quick look and test drive yesterday. Typically the engine ran beautifully when I got there and we had it idling for ever.. On a test drive he noticed the miss on acceleration, back at the garage it still idled beautifully. He is certain there's nothing wrong with the ignition. Acoording to him the trouble has got to be fuel supply, something causing variation here. He suggested going back to the steel pipe from pump to carb as a first try, rather than using rubber hose and the inline filter. He supposed there could become a "lock" there at certain conditions, giving lack of petrol when the engine suddenly demanded more petrol.
He also suggested fitting an extra earth strap, as he believed the excisting ones could be inadequate.
Well, I'm not sure but I think I'll follow his advice now and let him lead the progress. After all he is very experienced. So I'll try this out, and get back to him. That's the plan so far.
I'm puzzled to why the engine would idle so beautifully while we were standing there.. The only thing logical occuring to me is, it was standing rather downhill, front end lowest. Perhaps it could indicate restrictions in the fuel supply. Driving back it ran fine, also when parking. Starting it again after about 15 minutes, the miss at idle ws back:-) LOL, you just have to love this car...
Regards, Tommy
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Post by dave1800 on Sept 1, 2011 7:22:37 GMT
Your Crab is just teasing you, maybe it's jealous you have other cars to play with!
I'm sure you don't want to experiment, but a "MGB guru" has been quoted in a forum as noting that the best settings for the valve clearances are:
Inlet valves 13mm - HOT
Exhaust valves 15mm - HOT
but you must be sure that the engine is truly hot and not allowed to cool down before you set the gaps.
I have no idea whether the "guru" actually said this (I know of him and his name but won't post it as it is third hand information), but it does sound reasonable to me - no idea whether this applies to the Mk1/11 1800 engines and/or Mk111.
Any thoughts anyone?
regards
David
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Post by kelsham on Sept 1, 2011 8:13:24 GMT
Dave I have always understood that the gap is set so that as the engine warms up there will be a small clearance at the tappet. I am sure you already know this.
Over the years I have heard many people advise different settings for different reasons. For example Roger Bywater Jaguar specialist advises different setting to the Factory. I cannot at the moment recall his reason probably to increase power.
In the BSA car club some experts advise setting the tappets hot and removing the clearance completely? I ignore this advice and am happy with the result.
I would have thought if the tappets were set to the gaps your MG expert is suggesting the engine would be extremely noisy?
I suppose a test could be done by adjusting one tappet only and listening to the engine.
Regards Kels.
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Post by kelsham on Sept 1, 2011 8:13:47 GMT
Dave I have always understood that the gap is set so that as the engine warms up there will be a small clearance at the tappet. I am sure you already know this.
Over the years I have heard many people advise different settings for different reasons. For example Roger Bywater Jaguar specialist advises different setting to the Factory. I cannot at the moment recall his reason probably to increase power.
In the BSA car club some experts advise setting the tappets hot and removing the clearance completely? I ignore this advice and am happy with the result.
I would have thought if the tappets were set to the gaps your MG expert is suggesting the engine would be extremely noisy?
I suppose a test could be done by adjusting one tappet only and listening to the engine.
Regards Kels.
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Post by tommydp on Sept 1, 2011 8:32:42 GMT
Your Crab is just teasing you, maybe it's jealous you have other cars to play with! I'm sure you don't want to experiment, but a "MGB guru" has been quoted in a forum as noting that the best settings for the valve clearances are: Inlet valves 13mm - HOT Exhaust valves 15mm - HOT but you must be sure that the engine is truly hot and not allowed to cool down before you set the gaps. I have no idea whether the "guru" actually said this (I know of him and his name but won't post it as it is third hand information), but it does sound reasonable to me - no idea whether this applies to the Mk1/11 1800 engines and/or Mk111. Any thoughts anyone? regards David Hi Dave! I suppose we're talkin 0.013 and 0.015 inches here? I had them all set to 0.013 hot the last, of many, times:-) One valve/ tappet is still quite noisy though. Will get fine when engine is truly hot, but sometimes noisy even then. Regards, Tommy |
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Post by dave1800 on Sept 1, 2011 9:48:19 GMT
Hi Tommy, yes 0.013" and 0.015". I must admit that I used to set them all to 0.015" COLD rather than burn my fingers! I learned early on back in the mid sixties that trying to get rid of the tappet noise on the B engine was not just a waste of time but like Kels found out just a little too tight brings trouble. I had a mechanic friend who owned a garage and raced Minis; he used to set tappet clearances with the engine running; I could never manage it, but he swore by the method. Maybe your setting of 0.013 HOT isn't really fully hot, try loosening them 0.002" and see what happens, apart from being noisier! regards David Hi Dave! I suppose we're talkin 0.013 and 0.015 inches here? I had them all set to 0.013 hot the last, of many, times:-) One valve/ tappet is still quite noisy though. Will get fine when engine is truly hot, but sometimes noisy even then. Regards, Tommy |
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Post by tommydp on Sept 1, 2011 11:26:28 GMT
I'll double check the clearances.. It's interesting too see how minor adjustments to them alter the running. Checking which rocker is ticking with a very thin feeler gauge while engine runs, makes a big difference to the engine.
Wonder if it makes a difference to set the clearances at tdc firing, rather than by rule of nine? I think I tried that once too. My uncle says he and other young mechanics used to set the clearances when running in the sixties, but finally they were not allowed to do this by the chief mechanic at the BL garage:-)
Interestingly, I have a BL Norway Service bulletin from the mid seventies saying all 1800 B engines could have clearances reduced to 0,33 mm (0.013') COLD to overcome rocker noise. The Princess and MArina were designed to run at 0.33 cold, I believe.
Regards, Tommy:-)
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Post by threelitre on Sept 1, 2011 13:02:15 GMT
He suggested going back to the steel pipe from pump to carb as a first try, rather than using rubber hose and the inline filter. Now that reminds me something: I once had a Maxi with occasional lean running problems that got worse with time - but only in 5th gear and only when passing about 90kph. It could do 110 in 3rd  I first thought ignition, but an experienced mechanic spotted the inline filter the owner before me had fitted to the fuel hose (the one across the engine) and said that this will be the cause. He was right. Due to the car having stood a longer time, there was always some very small rusty particles in the fuel and these accumulated in the paper element in the filter - but on the backside of it that I could not see. When I changed in fith engine revs dropped and the fuel pump (engine driven) could not deliver enough pressure anymore. Try removing this filter - the SU's are very tolerant to all sorts of dirt anyway. Regards, Alexander |
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Post by dave1800 on Sept 2, 2011 0:33:22 GMT
The Mk111 1800 which has the longer pushrods and shorter tappets is also recommended as 0.013"; but given your problems I would play safe and keep to 0.015" until you can discount this. (Some of the Mk1 engines used a 0.018" setting). Interesting suggestion from Alexander about the filter, maybe could explain why sometimes it appears full and other times not? Regards David Interestingly, I have a BL Norway Service bulletin from the mid seventies saying all 1800 B engines could have clearances reduced to 0,33 mm (0.013') COLD to overcome rocker noise. The Princess and MArina were designed to run at 0.33 cold, I believe. Regards, Tommy:-) |
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Post by tommydp on Sept 2, 2011 6:41:45 GMT
Replaced the filter and hoses between pump and carburettor with the original steel pipe. After that it performed very well on the road, and the idle was stable and smooth. However, that was yesterday...
On my way to work today, of course it was back again. Missing after motorway cruising and missing at idle when i parked.
This is hopeless:-( However it now seems that working on the fuel supply makes big improvements, if only for a while... Suppose it's time to change the tank and supply pipe from tank to pump then. After all, it's the only thing that has not been touched. I recall I had a 1300 with a tank outlet which in some way was restricted.. I notice that when removing the pump inlet hose, there's no spill of petrol from the hose.. Not sure if it matters though.. The fuel filter was absolutely clean as far as I could see..
Regards, Tommy.
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I first thought ignition, but an experienced mechanic spotted the inline filter the owner before me had fitted to the fuel hose (the one across the engine) and said that this will be the cause. He was right. Due to the car having stood a longer time, there was always some very small rusty particles in the fuel and these accumulated in the paper element in the filter - but on the backside of it that I could not see. When I changed in fith engine revs dropped and the fuel pump (engine driven) could not deliver enough pressure anymore. Try removing this filter - the SU's are very tolerant to all sorts of dirt anyway.