smiffey
New Member
I'm sure I can find that extra few tenths somewhere...
Posts: 14 
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Post by smiffey on Apr 23, 2017 19:14:56 GMT
After my recent Goodwood day debacle which left me having one complete practice lap and a half, I thought I had solved the intermittent misfire/power loss issue following a compression test of 175psi per cylinder and replacing the points plus condenser. Although this allowed me two, count them, two trouble free days driving - the problem returned on Saturday when I decided to drive the Midget to Gurston Down to check the hillclimb out. On the M3 after 5 miles or so and at 70 mph the misfire returned. The engine revs freely when not under load.
I have now run out of my already limited ability and was hoping for a knowledgeable MG or A series guru to shine his/her guiding light my way! Is there any such person in the Hampshire area?
...... oh, and the floor mounted accelerator pedal now seems not to be so floor mounted anymore! This I can do myself.
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Post by username1 on Apr 30, 2017 9:38:42 GMT
Rotor arm is always the first thing you should try. There has been a run of bad ones available causing problems, it's so easy and cheap to swap it's worth giving it a try. Then convert to electronic ignition, I like points etc but the electronic are fit and forget - until they go wrong as well I suppose!
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smiffey
New Member
I'm sure I can find that extra few tenths somewhere...
Posts: 14
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Post by smiffey on Apr 30, 2017 13:23:21 GMT
Thanks username1, I will replace the rotor arm next.
I have had on and off blue smoke from the exhaust for a little while and this soils the spark plugs which also doesn't help. Initially I thought it may be valve guide seals but before I start removing the head I thought I would check the crankcase breather valve. There was a reasonable amount of oil in there and on disassembly I can see a small split in the diaphragm so will replace that as well. I wonder if the oily exhaust is from a faulty Breather valve?
I have upgraded the floor mounted accelerator pedal with the 'hanging down' version for want of the correct terminology and at least that is now ok.
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Post by username1 on Apr 30, 2017 22:14:27 GMT
The breather system can cause intermittent oil burning, I'm no expert on the PCV system though, I've never had a car with one, all mine have had an open system. If you need a good read on A Series intermittent oil burning then check out the archived threads on the MG Midget BBS, it goes on for pages and pages!
The 'hanging down' version is the one from the 1500 Midget, all others were organ type. In fact you've reminded me that I need to get one for the car I'm restoring as I'm also not keen on the organ type. I'll have a look on eBay.
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Post by username1 on Apr 30, 2017 22:29:26 GMT
Slark Race Engineering are reasonably close to the west of Hampshire in Amesbury. I've no experience of them but they are A series specialists and have a rolling road if you need a tune up anytime.
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smiffey
New Member
I'm sure I can find that extra few tenths somewhere...
Posts: 14
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Post by smiffey on May 4, 2017 18:37:08 GMT
Thanks for the Slark info.
I replaced the split PCV diaphragm and no oily smoke appeared during a 3/4 hr test run at speed (legal limits of course)! The spark plugs did not oil up either but there was a small residue of oil in the crankcase breather valve which I had cleaned out before the test. I assume that there shouldn't be any oil there.
I'm waiting to install a catch tank, with it's own breather, which I hope will stop any oil reaching the crankcase breather valve. Not sure if the catch tank should be installed higher than the engine or if that does not matter.
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Post by username1 on May 5, 2017 12:16:25 GMT
Shouldn't matter at all where it is. Mine was where the battery sits for a while and now is down on the chassis leg near the gearbox, no problems in either place.
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smiffey
New Member
I'm sure I can find that extra few tenths somewhere...
Posts: 14
|
Post by smiffey on May 8, 2017 17:18:25 GMT
Oil Catch Tank fitted, however the epic saga continues. Just to recap, I had oil smoke blowing from exhaust and wet fouling of spark plugs. There was a split in the PCV diaphragm. This has been replaced and an oil catch tank with breather added. In between these events and during a test run, the PCV top had come off whilst driving. When I stopped I also noticed oil had sprayed out from where the sump joins the engine - onto the chassis. When back home and with the engine ticking over I could feel air coming from that area. Attached is a picture of an engine with a bolt ringed in yellow. This is where the air and oil is coming from on my engine. My first assumption is that the bolt on my engine had come out but on looking at other A Series engines I noticed some had a bolt and some didn't. I have just fitted a bolt to the hole and hope that's that - or will crankcase pressure issues continue..... Attachments:
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Post by username1 on May 8, 2017 22:13:27 GMT
Mmm, not sure on that one! For a start the engine in the photo is from a Morris Ital so is slightly different to the Midget engine. I can't recall there being a bolt in that area, especially one that would go right through into the crankcase. One thing is certain is that nothing should be coming out of the engine in that area so you've done the right thing in closing it off!
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