Mine died today

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m3a1
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Re: Mine died today

Unread post by m3a1 » July 15th, 2018, 11:38 pm

Well, I like to do the easy tests first just to assure all the boxes for the basics are covered first...

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Re: Mine died today

Unread post by kmam » July 17th, 2018, 8:51 pm

Compression when turning by starter motor is just over 100psi on all cylinders.
Howard

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Re: Mine died today

Unread post by kmam » July 17th, 2018, 9:03 pm

Yesterday my old-school mechanic mate went over it and did most of the things we had already done, drained and checked the fuel from the tank and also put petrol in each cylinder to see if that would start - it did not. At his request I bypassed the distributor condenser (which I had previously done) and it started! We stopped and started it several times without problems, although it was not running smoothly, then ran it long enough to set the timing (it was just about spot on) which advanced smoothly with increased revs, adjust the mixture (using an exhaust gas analyser) and set the idle (about 750rpm). Elated at our success we then took a break for a cuppa after which we set out to take it for a run.

It started, idled rough and died. Did this three times and that was it: would not even try to start! Took it out and towed it to try a clutch start but not a kick!!!

Really not sure where to go from here. He is suggesting that maybe we should revert to a standard (non-electronic) ignition which could be easier to analyse. The other possibility is to see if a local long-term established auto electrician can do tests on the distributor (they have some long-standing staff who were able to do up my Series 2 Land Rover starter and generator).

I must say that when I got home I had reached the point where it seemed the best way out is to sell it "as is, where is" but my mates have talked me out of that (for the time being at least!). The thing is, it defies all logic so I guess the solution is going to be found by not thinking logically!

Howard :roll: :(
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Re: Mine died today

Unread post by rickf » July 17th, 2018, 9:09 pm

Progress! What that tells me is that the basic engine is fine. I think you are on the right path with a points distributor and I am pretty sure I mentioned that a while back. Whenever in the back country keep it simple. You are not only going into the back country but you also do not have access to parts for the electronics nor the ability to diagnose them. Points are bare essential simple. you can clean them with a match book. You can set them with a match book. Keep a couple sets in your repair kit along with a couple coils and a few fuel filters and the tools to change all of the above which is very minimal. I went back through the thread and all through whenever you mention spark it is weak. This could very well be a symptom of a bad ignition module which could also be firing that weak spark way out of time. I think the best thing to do right now is go to points. Disconnect the negative wire from the coil and put a jumper wire on there and turn on the ignition. Have someone hold a plug wire with a spark plug on it against the center terminal of the coil and ground the plug against the block. Now, with the switch on, tap the jumper wire to a ground. Just tap it for a second, like points closing and opening. See what kind of spark you are getting on the plug. If it is nice and hot then the problem is probably in the module, the dwell time is not long enough to build up the energy in the coil hence the weak spark and probably off timing.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: Mine died today

Unread post by kmam » July 17th, 2018, 9:31 pm

Yeah, you did Rick. Trouble is getting my hands on the bits and the time/cost of getting them here. I will post in the wanted section.

My mate just rang and pointed out that we have not tried feeding 24V direct from the battery to the distributor in case there is a voltage drop under load - a long shot but who knows? Will give that a go next time I am over there (it is still at my mates place).
Howard

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Re: Mine died today

Unread post by Grasshopper » July 18th, 2018, 9:53 am

We had a not dis-similar problem with a points distributor on a WW2 GMC. Everything was tried, including swapping parts from other trucks. In the end there seemed to be something wrong with the actual distributor shorting to earth, but despite swapping all the guts from a known good one, it still showed all the same symptoms. We tested and megger tested everything and consulted all the experts and books we could, but for some reason the defect was with the body of the distributor. To this day we still don't know what the issue was, but installing a new distributor cured all the issues. It was most frustrating. Good luck with your ongoing investigation!

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Re: Mine died today

Unread post by rickf » July 18th, 2018, 1:25 pm

Could be the distributor is not making a good ground but if that were the case he would have no spark anytime. Be aware that the M38A1 uses the same distributor internals and I am pretty sure the M38 internals will work also. Not positive about the M37 since it is a 6 cylinder, the cam will naturally be different but the points plate may be the same. I will see what I have around here.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: Mine died today

Unread post by kmam » July 18th, 2018, 6:37 pm

Rick

I am starting to believe in mental telepathy! At about 0130hrs today (GMT +10) my dog woke me up wanting to go outside to pee. After coming back to bed, while waiting to fall asleep, I was running over the issues with the MUTT and came up with the same point - check the earth - about the same time as your post! I have added that to the list of things to be tried next time I get to the MUTT (it is a one and half hour return drive). The plan is to connect both +ve and -ve directly to the battery (not leaving it connected when not testing of course!).
Howard

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Re: Mine died today

Unread post by rickf » July 18th, 2018, 9:07 pm

A bad ground from the distributor to the block is a real long shot and the fact that it did run for a bit makes me think that is not the issue. Plus if you moved the distributor to change the timing then that would have reestablished the ground. I am thinking the module is bad, that is why I suggested the coil test with the module disconnected.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: Mine died today

Unread post by Hambone » July 18th, 2018, 9:31 pm

I'm with Rick, either the coil or electronic ignition, I would start with electronic ignition, you could go back with the points system but the Swiss modules are very reliable. Red River has NOS Swiss modules for $60.

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Re: Mine died today

Unread post by kmam » July 19th, 2018, 1:08 am

I have replaced both coil and Swiss module without any change, sadly.
Howard

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Re: Mine died today

Unread post by kmam » July 19th, 2018, 1:42 am

I just did some tests with the Swiss Module that I took out. If I apply a 24 Volt source +ve to the red wire, -ve to the black wire and connect a multimeter to the red and green wires the meter reads 18.8V. When I pass the interrupter between the magnet and the sensor on the module the voltage jumps to 23.3V. Allowing for the accuracy of the power supply and meter I am using I assume this to be correct and the pulsed increase/decrease in voltage as the interrupter passes the sensor would then induce a high voltage into the secondary of the coil.

I get exactly the same result with the condenser in series with the +ve connection.

I have never measured this on a points set but I am guessing that with points the voltages would be 0V and 24V respectively?

Can anyone confirm the results I am getting are correct?
Howard

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Re: Mine died today

Unread post by m3a1 » July 19th, 2018, 1:49 am

Check the health of that lead to the capacitor (did you call it a condenser...with a swiss module?)

Anyway, that was the last thing you fiddled with and suddenly it came alive again.

Might the lead be compromised in some way? Could it be that when you were checking that out, you reestablished a connection at some point in the wire?

Cheers,
TJ

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Re: Mine died today

Unread post by kmam » July 19th, 2018, 3:40 am

Condensor, capacitor (remember the song "you say toma(h)to I say toma(y)to"?)

Yeah I have checked the lead, twisted it all directions to see if there was a fault in it, checked it on a multimeter and a component tester which show zero ohms. The engine came alive (temporarily) with the condenser removed from the circuit and a direct connection made.
Howard

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Re: Mine died today

Unread post by rickf » July 19th, 2018, 8:49 am

If you are only dropping from 24 volt to 18 volts that can be a problem since it is not going to allow the field to collapse in the coil and therefore not fire a good spark or no spark. I can't say I have ever tried that kind of test before but if you do not zero the voltage the coil will not fire. Now try what I said and see what kind of spark you get.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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