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MG TD TF 1500 - 51TD engine restart

Well, I keep running into snags. Had the engine firing- ran for a few minutes - before going on vacation, but ran into problems with engine grounds and a non-running starter.
Installed an engine ground, rebuilt starter, installed new battery; starter then ran fine but no firing.
Two weeks off travelling....
Today I worked on cleaning and retightening grounds and got the engine firing again, but its very erratic and won't keep going. I don't think I've got spark to more than a couple of cylinders.
Tomorrow I'll pull and check the plugs for fouling.
Then I'll look at distributor advance, wires, timing etc.
One small step at a time...
Geoffrey M Baker


Since your checking all wire connections etc.--- I've seen cars where the ground wire for the early distributer is missing. See photo


Richard Cameron

My main engine ground wire was missing... Now replaced... But the distributor wire is there. I cleaned up those connections too...
Geoffrey M Baker

And this morning, she ran smoothly. Ran her for about 60 seconds and stopped. All looking pretty good!
One problem I had yesterday was I suddenly thought I had wired the distributor wires wrong (1342, I had 1243) and it fired erratically... woke up last night slapping myself and realizing it is Anticlockwise, so it was in fact correctly wired... switched 3 & 2 wires back again this am and she ran perfectly.
So my starting problems were most likely just grounding issues, and after cleaning up the distributor ground wire yesterday I fixed it.
So today, as I said, ran well for 60 seconds.
Two issues still:
Oil pressure is about 40-45 on an idle with the choke out. Keep in mind as part of the rebuild I rebuilt the pump (new gears, machined the internal faces) but I also removed the PO's bolthead which had been added to the pressure relief spring, to increase spring tension and give an apparent higher oil pressure)... Additionally I moved the oil meter takeoff from the top to the bottom of the block. This should improve oil pressure, but at the same time I drilled out the top hole which had been filled and redrilled, so that there was probably less than an 1/32 hole for oil to squirt out of to the head). Because I switched the fittings, I just drilled that out to make sure the bottom got plenty of oil (as that fitting is now on the bottom).
So I *think* my oil pressure is OK, but any input and suggestions would be appreciated. I could solder and refill the top fitting and drill it out with a smaller hole, as was done previously, but this appears to be a "shade tree" mechanic repair, not done by the factory, and I haven't heard anyone recommend the necessity. However, it would still be nice to improve oil pressure a bit?

The only other issue is that the crankshaft pulley still gets quite hot to the touch after running at speed. I believe this is because the fit between on the sump and chain cover is extremely poor and that the rope seal is tight and rubbing the pulley. I suspect the sump may have been changed later, as these two parts are really a primitive fit! I'm thinking the best thing is just to let it seat itself and wait for it to cool down after more time running...
Suggestions, thoughts?
At any rate, I'm pleased that I'm back on track to getting Lily Christine IV running again for the New Year.
Geoffrey M Baker

Have run her again twice, each time nice and smoothly. Now she's smoking a bit (burning off oil around the engine) which is also to be expected.
So far so good...
Geoffrey M Baker

40-45# at idle is fine oil pressure; it will no doubt go down a bit when hotter. Keep looking for, and fixing, the small oil leaks.

Tom Lange
MGT Repair
t lange

I'm very happy to report no current visible oil leaks! Naturally, some of the smoking is coming from oil on the engine, and that may trace back to slow leaks... but so far, the area under the engine is cleaner and dryer than it's ever been...
Again, ran for 3 minutes. All looking good.
It's time to start thinking about timing and tuning. Pretty soon, maybe even moving the car :)
Geoffrey M Baker

No visible oil leaks! Another Festivus Miracle!

Congrats on a successful rebuild. How long till you are back on the road?
Charles Duffy

Charles, I know it sounds unbelievable! But keep in mind once the car starts moving there will be more opportunities for leaks...
Geoffrey M Baker

Hope to be back on the road as soon as she is tuned and timed and I hav the bonnet back on and the carpets and seats reinstalled...
Geoffrey M Baker

I forgot, I also need to put a boot on the pedal box and install bushings on the steering column and reinstall the steering wheel. I know, not an essential item for driving, but it does come in handy.

I have to say, I am in awe of the lack of oil leaks. I'm sure it won't last, but I guess we did most things right during the rebuild :)
Geoffrey M Baker

Ok, you folks did it again. The things you learn. Owned a TD for 42 years and never heard of a grounding wire on the distributor.

Can you provide more detail on how it attaches to the distributor?
Bruce TD4139 Cunha


Bruce, The original wire was cloth covered black about the same size as found in the parking light circuit as an example. It was about 8 inches long with round spade terminals soldered on each end. One end (8mm or 5/16")attaches to one of the rear generator mount bolts and the other (6mm or 1/4")to the distributer clamp bolt.
I suspect a lot of them are left off after engine rebuilds because people think the distributer clamp should be a good enough ground. However, in actuality, the distributer floats in its mount and when nicely coated with oil, it can loose its electrical connection intermittently. Unfortunately, I have not been able to find a picture in any of the manuals or factory literature, so I'm referencing mine, and what I have personally seen on cars I have worked on in past years.
I only learned this lesson by accident a few years ago when I turned around one day and the car I was working on stopped running on its own without my touching it. After quite a trouble shooting adventure, I discovered that I could make it run smoothly by just pushing on the distributer lightly with my hand. When I compared this cars configuration to my own, I discovered the missing ground wire problem.



Richard Cameron

Does anyone have pic of this original wire? Cheers
Peter TD 5801
P Hehir

Bruce, I have owned my TF for 43 years and also do not have the ground wire. I have seen it mentioned in these discussions and could not imagine where it went. Richard, thank you so much for your explanation.

Gary
G B McGovern



Don't want to hi jack Geoffrey's Thread, but one note to add: This ground wire to the distributer is not needed on later engines with the pin and machined clamp that is integral to the engine block.
Richard Cameron

Well, I was missing my engine ground cable for umpteen years without ever noticing it. Wasn't till the rebuild, when - what with all new painted surfaces etc - I started having electrical trouble with both starter and distributor, and finally realized the problem. For some reason, though, the distributor ground wire was never thrown away by a PO!
As Richard says, though, the distributor ground wire many not have been standard on later cars and later distributors. Maybe the TFs never had one?
And yes, my wire (not original, plastic coated) runs from the distributor ring clamp bolt to the generator mount. It was on the generator's pivot point bolt, but I moved it to the generator's engine block mount bolt, think that, it being absolutely fixed and not pivoting, might be a better ground point. Sanded the block, mount etc to get bare metal, made the connection, and everything suddenly went right :)
Geoffrey M Baker

This thread was discussed between 05/01/2016 and 07/01/2016

MG TD TF 1500 index

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