sorry to bother you with a technical problem showing up in a carbed Triumph Spitfire. I put forward the same problem maybe one or two years ago - then it went away and reappeared some days ago:
In 2014 the engine was reconditionend. Immediately afterwards a problem occurred that the hot engine wouldn’t restart. More precisely: The starter would start to turn, but not manage a revolution. Typically things would settle after some 15 minutes.
Dave or Frank then uttered concerns about the pistons sitting too tight and maybe jamming following heat expansion.
Then I replaced the battery and found that in similar situations I could restart the hot car with WOT - my money was on a steam lock of the combustion chamber preventing the engine to be turned. When I already had bought a new heat shield to be placed between the exhaust manifold and the carbs and was ready for the manouvre I experienced a new development: Firstly I couldn’t resolve the problem with a full open throttle and only yesterday the problem reappeared on a fully cold engine. So no steam bubbles either.
So far the engine has made several thousand miles since the rebuild without any problems. No heat issues whatsoever.
The starting problem has presented itself entirely intermittent. At times the starter would initially just make a tired half turn and then stop, and on the next attempt one second after turn over the engine merrily. I have checked the dynamo. Charging voltage is good. I have also opened, cleaned and greased all high current connections at the battery, at the ground wire and at the starter. I have never tried to confirm by hand whether the internal resistance of the engine to turn was increased in such no go situations.
For the moment I’d assume there is an electrical problem on the high current side of the starter circuit either outside or inside the starter. Of course I could order a new starter. It’s just that the starter otherwise works perfectly, as it doesn’t jam and regularly engages to the flywheel.
indeed there is a starter solenoid and it is the only item between the battery and the starter. To my understanding the starter solenoid is a magnetic switch that basically “starts the starter”, so it should either work or … not. When I turn the key the starter relay obviously works and - I think - the solenoid sets the starter in motion, if only to a very limited extent. Is there an intermittent partial failure mode of the solenoid, such as maybe letting only part of the power get to the starter? That’s how it sounds.
The only scenario I can imagine is that the “bridging” of the ballast resistor for the starting process occasionally doesn’t work and the starter only receives 6V. Will put a DMM into the car and wait for the next failure …
would the engine still do that with ignition disconnected (or timing retarded)?
My starter used to have a very hard time to turn the engine on a few cylinders, especially when hot. It would turn nicely, then come to a rather sudden stop and only slowly, if at all, crank past that point. My money was on the starter or head gasket until I retarded my timing… and found that my distributor was loose! I would rule ignition out if you haven’t already.
WOT used to help in my case which is why I suggest checking, and also it would start just fine sometimes.
Good luck,
David
If its the type I think it is then the solenoid throws in the pinion gear and closes the stater motor circuit it may pay to strip it down and check the heavy duty contacts?
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Robin presents the best scenario, Jochen - the starter solenoid contacts are likely burnt…
…and/or the bore of the solenoid is dirty - preventing consistent movement of the plunger. Insufficient bridging of the contacts will also cause increasing scorching of the contacts, further aggravating the problems. Dismantling and cleaning the inside of the solenoid may resolve the issue - but it is certainly relevant.
The problem may also be hanging/worn starter bushes, and as the starter/solenoid assembly must be taken out for solenoid attention; starter brushes and commutator should be inspected. Either condition may cause intermittent or weak starter action due to insufficient current flow…
The ballast resistor plays no part; it is bypassed during cranking to increase coil voltage - and can play no part in cranking difficulties…
No, David, I haven’t checked the timing as of itself, as the engine, once it runs, behaves just right: leaving a roundabout in third the car just pulls away from little over 1000 RPM and it revs out to 5000 RPM happily. So it seems both timing and vacuum advance are in order. Of course, the advance mechanism might stick. I’ll keep that in mind.
Robin and Frank, you’re certainly right in that I have to pay closer attention to the starter solenoid. It’s just that - unless I’m confused by English terminology - different from our Jags’ construction in the Triumph the starter is separated from the solenoid: Solenoid:
Apart from your pertinent remarks as to starter brushes and commutator, do you think it is possible to take apart the solenoid? - The ROM does not mention this possibility.
Finally, Frank, I’m aware that a broken ballast resistor cannot affect the starter, but an intermittently functioning bypass of the resistor (the w/y wire leading to the solenoid) would lead to a significant drop in starting voltage, wouldn’t it? This would seem to be the easiest starting point
Last thing: During my online research I found several reports of defective new starter solenoids. Is there a standard practice of checking function before installation?
It looks as if you might be able to drill out the four rivets and split the case to check the internal contacts, however it looks quite new?
My previous post asssumed that it had a pre-engaged starter, where the solenoid throws the pinion into mesh rather than the one you have which relies on inertia to throw the pinion forward to mesh with the F/w
the picture of the solenoid in the blue car is just taken from the internet, it’s not my car. In fact, mine is probably still original, but looks quite good. I just checked all connections: The spade and bolt connectors are good as are the Lucar connectors and the rings. I filed the rings shiny and put some battery grease on.
My hope that the w/y bridging connector might be somewhat compromised was not supported. Spade shiny, conector tight, no untoward bend in the wire.
I won’t invest much time in the solenoid - at a price of approx 10 EUR for a replacement part. Yet, I’d prefer to be sure that the replacement part is better than the original.
Veeery interesting !!! The picture, as is usual, tells so much.
It is a solenoid, indeed. But, differing from Jaguar and other applications, single purposed.
A heavy duty relay so to speak. Provide volts and lots of amps to the starter motor. No mechanical duty of shoving the drive pinion on the starter forward to engage the ring gear.
Old Fords used a similar architecture.
A couple of decades ago my daughter’s Ford Ranger pickup developed crank issues. Similar to the Spitfire in question.
I managed to take it’s solenoid apart. It looked just fine ???
Just did not make the required connection when power provided.
So, I merely replaced it. Yahoo, its Pinto engine fired tight up.
I “decided” that it’s plunger needed magnetism to work when energized and that had been lost.
I tossed it, so as not to cause mischief elsewhere.
As I type, I recall that at least some of the Ford based solenoids had a mechanical option. A button on the case. Press it and it moves the plunger into contact and the starter
cranks.
So here, I have two suggestions:
Replace it.
Bench test for continuity. Two circuits to test. The trigger one and then the load one. It should be definitive. And my guess is that at least one will fail those tests.
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The simplest test to verify the solenoid function is to bypass it, Jochen - it works with any kind of starter system…
That you have an inertia starter, as Robin remarks makes no difference - the solenoid function just connects the battery wire to the starter. With the pre-engaged starter, solenoid integral to the starter, lack of access makes it a dicey operation on ‘our’ Jaguars. Hence I omitted to mention this test - it should be simple on yours, using a hefty jump like a starter cable…
The solenoid function test is just to apply power to starter relay white/yellow (or whatever colour connects it to the solenoid) - the solenoid should vigorously react, and connect battery connection to the starter. The reason why a ‘solenoid’ type rather than a relay is used is the extremely high current through the contacts - adding that the very rapid action of a solenoid reduces contact burning…
With the inertia type; as the starter starts spinning the pinion is ‘thrown’ into mesh with the starter ring gear - and stays meshed until power is off - a spring and the rotation of the ring disconnects the mesh.
Overall point being that if the starter action is consistently perfect when bypassing the solenoid; the fault is the solenoid. If starter action is still iffy; the fault is the starter itself - assuming that the engine itself is unlikely to cause the cranking problem…
However, while cleaning the body connection from the batter is mandatory; as the rubber engine mounts tends to insulate the engine from the body - ground straps are usually fitted to ensure good body contact. To bypass faulty ground straps; connect a starter cable between battery ground post and engine block…
Intermittent cranking problems may result from any of the elements mentioned - causing either insufficient current to the starter (connection comes and goes), or a starter fault (commonly hanging brushes).
As with all intermittents; patience is required to catch the fault when it is present - tests are inconclusive unless response is consistent over time…
Hi Jochen, on the off chance that you have one of those green topped rotary battery isolators fitted to the Spitfire - remove it and throw it as far as you can. Had one on our E type and it took me a while to work out what the problem was. Paul
it looks like I have ruled out any cheap “check wires and connections” solutions to my problem and the only question is whether to change both starter and solenoid simultaneously or proceed from one to the other, if necessary.
Paul, you’re dead right - I had one of the brass kill switches with the green topped bolt in my car until yesterday and removed it as a remotely possible source of trouble.
Upon all contact care at the solenoid and the removal of the kill switch I started the cold car a couple of times without any problem. However I was under the impression that the first turnover of the engine always occurred over a higher resistance than the following.
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In any fault finding process priorities, Jochen; start with the easiest tests, then the difficult ones. Items not to be replaced unless proven defective - but if you decide to anyway; start with the cheapest…
But after each change, like the kill switch removal; with intermittent faults you patiently wait till symptoms return. If they do not; there is no point in further work - you cannot find faults without symptoms present…
It’s just that an intermittent no start situation is about as bad as it can get, as, by definition, you start a car only when you want to go somewhere, indicating a certain urgency. That’s why my patience is a bit stressed … Years ago I had a 1964 Ford with a 6V system and a cold start problem. These days I developed the habit to find parking spots only on a hill with enough space permitting to get going based on gravity. Today I’m less tolerant, I’m afraid, and currently shopping for a new starter …
64 Ford on 6 volts? Domestic Fofd went to 12 about 56, as I recall. If a European, I’m surprised as europe went 12 long before we did.
There is an emergency way to get a crank at times, Limited in number. Give it a sound whack,. I resorted to percussion maintence on my Jeep a couple f years ago. No crank in a shopping center about 15 miles away. I was thinking “flat bed” or local fix. Did the clean the cables thing. They were clean.
As a last or close to it option, I did the whack. Yahoo, it cranked right up. Straight home, do not stop and surely don’t turn off the engine., Parked in a safe spot in my drive. Rebuilt starter and all has been well.
Crude old tech emergency crank. Topside at the solenoid on similar cars. Gloved hands on a pair of pliers. Bridge the two large posts.
Circa 47 or so, my tired 37 Ford had starting issues. Cranked, sorta, but no fire. Did the park on a hill routine for a few months. Fixed, two engines later…
Did you swap in a new solenoid?
And, if you go for a starter, it would be a rare thing to fall on a new one. More likely a rebuild. And, over here, quality varies, a lot.
I’m reading an article in Auto Restorer. A Spitfire. Engine choices slowed the author
old Europe only received 6V from Detroit. It was a nice car though https://en.wikipedia.org/wiki/Ford_Taunus_P4 (I had the Coupé in two-tone OEW over peppermint green) and I deeply regret having sold it in 2002.
I’m still in the shopping phase for the Spitfire. You’re dead right: Even “new” spares are all too often a far cry from the quality of the original. I “used” three starters for the Spitfire, before I got the one that now has served for well over 20 years.
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By all means, Jochen throwing money at a problem is one way of solving it…
With an intermittent fault it pays to deliberately run each test multiple times - to verify if during the test the fault does not appear; ie, not just faultfind when you need the car. If the fault recurs with a bypass; the bypassed item is not the problem. It’s easier with a high frequency intermittent, or if the fault occur in specific circumstances. But just replacing an item leaves an unnecessary expense - wasted if the fault remains, though it doe leave you with a tested spare…
While the starter itself sure is a suspect, internal faults are not intermittent - except for the brushes. So, when you take out the starter, at least check the brushes…?
The olds starter with a bit of refurbish may equal or even surpass a market rebuild.
They are relatively simple electric motors. Clean it up. As Frank suggests, new brushes. I’d add, wipe the armature, undercut the segments. Replace any “loose” bearing or bushing and it will more than likely be just fine for many cycles.
for the moment I have ordered a new starter solenoid at 16 EUR bound to arrive tomorrow. Unfortunately, I’m bound for some travelling until next Saturday. Maybe I then feel like changing the solenoid or I simply keep it in the shelf for the next re-occurrance of the no start stituation. If it’s not the solenoid the money is no total waste and the amount is tolerable.
The Spitfire starter motor is a simple thing as can be seen in the picture above, and the wearing parts can be had at very reasonable costs. I might make a winter project out of reconditioning it, if the exchange of the solenoid doesn’t help: Removal time is less than 20 mins - XJ drivers with AC may dream of this - then I can take the time and see what may need replacement to reinstall prior to un-hibernation.
