Hot engine won't re-start 'till cool again.

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peterwight
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Hot engine won't re-start 'till cool again.

Post by peterwight » Fri Nov 13, 2015 11:40 pm

I stop my valver after a long drive. Then it will not start again. Hot engine equals incomplete action from the starter.Key turns and produces all those clicks en route to the starter motor grabbing that flywheel. Except it doesn't. Silence. Later, perhaps an hour (or less on a cold day with bonnet up) the starter behaves vigoorously as tho' nowt wrong.
Heat is the only factor. I wonder if there's an electrical link somewhere, the expansion of which breaks that link, like an electric kettle switching off. I've replaced the moter twice and the wiring below the key. Trawling way back through ideas on this subject on this very site, I read that another member had cleaned all the oily mucky wiring wot gets ignored under the battery. So I did that and thought I had the problem solved. But no: it's happened again. I've been push~started all over the country, e.g at the end of the Tyne Tunnel by one of those trucks with the big cushions on their bumpers. Etc.

Please everybody, suggest what might be going on. Whether from experience or informed guesswork: gimme ideas !! Yours.PW
A BX fan since buying a 1983 1.6 in 1987 and subsequently a 1.9GTi, three 16valvers and a diesel Meteor. Their deaths have us done parted, save for one 16V sold for restoration, hopefully underway.

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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Sat Nov 14, 2015 7:14 am

I had trouble (on 1.6 petrol) when the starter motor brushes were worn out. Might be worth a check, it certainly behaves in an odd way. If the valver starter motor is similar it should strip down easily enough to let you see. If it is a new starter or recon it should be OK, mine was a prematurely failed recon version. The brushes were available as sets which you can solder on. it is also possible that the solder joint from one of the brushes is dodgy (the non brush end ie body of motor end) - it is quite hard to get a good clean joint at one end even with intense scrupulous cleaning and good flux. It may be breaking down there with heat. If it is dodgy it may even come off in your hand, so be prepared!.

BTW do not forget to clamp the braided copper to stop solder spread if you resolder this/these parts.

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Re: Hot engine won't re-start 'till cool again.

Post by peterwight » Sun Nov 15, 2015 1:48 pm

Thanks for your reply. I have had the starter replacec twice, on the assumption that the first one was a failed recon. But the fault persists (and I've paid for this work because you can't just lay hand (or eye for that matter) on the thing or it's cables 'cause it's under other bits. There was one occasion on which the system was worked excessively: I was turning it repeatedly until realising that the fuel pump wasn't supplying petrol. Perhaps that has strained something?
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Re: Hot engine won't re-start 'till cool again.

Post by Jaba » Sun Nov 15, 2015 8:14 pm

The starter motor contacts in the ignition switch are not the most durable things on a BX. What some have done in desperation in a situation like yours is to fit a relay to energise the starter solenoid either working off the switch or off a new push button starter switch installed on the dash somewhere.

But first a bit of diagnosis. If this were mine I would measure the actual voltage at the starter solenoid when the starter is turning. Then with this knowledge measure it when the starter won't turn. If you have a value above 9 or 10 volts then you probably have a duff starter (again). If its a lower value then all the connections in the engine bay on the starter circuit will need checking and cleaning, they are in the gearbox/battery tray area and then there is the ignition switch as a suspect.
Perhaps a push button starting circuit might turn out to be the best solution.
Good luck with this frustrating problem.
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Re: Hot engine won't re-start 'till cool again.

Post by barry badger » Sun Nov 15, 2015 9:43 pm

several things spring to mind in addition to all mentioned:-
is the battery ok! can you get it tested somewhere
what make is the reconditioned starter, i've had a lot of trouble with some brands over the years
is the engine running too hot and being too tight for the starter to turn, can you try turning it by hand with a spanner when it fails to start?
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Re: Hot engine won't re-start 'till cool again.

Post by themildbunch » Mon Nov 16, 2015 9:50 am

Haven't had this on my valver but both my diesel BX's have had this to a greater to lesser extent... it is / was the wiring in both cases.. behaviour would be similar to yours: starts ok when cold but when hot would just be a click but after several attempts the starter would turn... one diesel was repaired by replacing the wiring from the start solenoid - this gets lots of oil muck and the connecters can loose grip over time..

My other diesel was pretty much exactly like yours and it was partially solved by cleaning the main earth connection to the gearbox - this also had it's star washer missing and replacement of this has improved starting although it still sometimes clicks - worse in dry weather but it will always start now after two or three attempts.. I'm going to replace the large block connector under the batter next - I think Matt had similar issues and this solved the problem...

Worth checking connections for voltage drop if you don't want to keep replacing things though - but most BX wiring is of a similar poor quality!
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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Mon Nov 16, 2015 11:47 am

[quote="themildbunch"

My other diesel was pretty much exactly like yours and it was partially solved by cleaning the main earth connection to the gearbox - this also had it's star washer missing and replacement of this has improved starting although it still sometimes clicks - worse in dry weather but it will always start now after two or three attempts.. I'm going to replace the large block connector under the batter next - I think Matt had similar issues and this solved the problem...
[/quote]

Well said TMB, pretty much always the first port of call if any electrical gremlins show up - the main earth strap onto gearbox rear. Had one recently on the low level coolant circuit after replacing the actual switch in the radiator and it was corossion in the relay connectors by the radiator. Do not ignore the solenoid itself on the starter, you can check whether to is sufficiently free to move. Ensure battery is disconnected when messing around in the area of the starter as I'm sure your aware the current can give quite a shock.... :wink:

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Re: Hot engine won't re-start 'till cool again.

Post by peterwight » Thu Nov 19, 2015 5:57 pm

A quick thank you to all who've replied: I'll come back with more detailed reply. HOWEVER For now, owing to my belated and rapid learning about the switch that turns on the engine cooling fan (that 3 pronged thermostat on the rad), I find Barry Badger's suggestion very credible: 'is the engine running too hot and being too tight for the starter to turn' he asks. I've discovered that i've been driving with a blown fuse and therefore no fan, for a long overheated time. This current focus on fans has prompted my new query. Yuors PW.
A BX fan since buying a 1983 1.6 in 1987 and subsequently a 1.9GTi, three 16valvers and a diesel Meteor. Their deaths have us done parted, save for one 16V sold for restoration, hopefully underway.

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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Fri Nov 20, 2015 10:10 am

I've been having a similar slightly hot start problem on my 1.6. It will turn or did (later) and eventually fire, though it might take 3 minutes to go... Well eventually I got the starter to stop turning whilst it was spinning over, when the key position was to turn starter over, this is with a fully charged battery so my conclusion is the ignition switch is the faulty component. I got some guys to push and it went first hit, so I got home OK. You can hear the relay and solenoid come in, I've stripped and cleaned the carb twice, there is a spark at the plugs, though probably not as strong as should be. As the spring return on the ignition barrel is shot anyway I suspect something is either shorting the start circuit or it has simply failed, probably the latter. If it does not go after this I'll change the coil and ignition module but the starter stopping mid throw was the giveaway. No reason to suspect the starter motor or batteries at least not yet. I've ordered a s/h item but not sure how I'll run round for the next few days....will come up with something, probably hotwire it.

It takes quite a bit to actually get the warning lights, amber and red to come on IF the car is moving through the air. The radiator is pretty good, if clean internally. I did from Torquay to Stonehenge once 4 up plus towing a boat and only the queue on the 303 prior to Stonehenge brought on the red death lamp - I stopped!. The three pronged fan switch connector can be shorted (2 spade end short wire) as a quick test. Do this with the ignition off, then turn on and it should bring on the fan with the ignition key (you may need to try more than one combination of connection of the three).
Not forgetting that mostly electricity works better cold and breaks down with heat. A lot of normal components have an operating window up to around 80 deg C though Military spec stuff often goes to 130 deg.
It does appear that the fan switch on 1.6 and 1.9 petrols are a relatively weak item. Can't speak for other engines, though never went on my 1.4 in 175k, but done 2 on 1.6 in about 105k.

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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Sat Nov 21, 2015 9:56 am

I will be running a number of 'diagnostics' on the beast today. In no particulatr order, swap ignition switch beyond the keyed barrel as I have a spare working lower part (tumblers had to be smashed because some idiot snapped key in barrel - not me). Check main earth strap and reground, starter solenoid, brushes, replace motor if necessary. replace coil, replace ignition module, clean relay contacts. Most of the rest of the system is new ie plugs, dizzy cap, rotor arm leads OK, carb is whistle clean etc etc. I will check the leads though esp the main coil to dizzy cap one as this has in the past on other cars been a source of trouble.
My inclination is that it is the ignition switch shorting the ignition circuit whilst trying to start! It might sound odd but I've had enough weird gremlins in the electrics such as no rear screen heat, wipers come on without actuating. I'd put these down to water in the fuse box and relays but an ignition switch short can also do this as I had in my old Chrysler Sunbeam.

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Re: Hot engine won't re-start 'till cool again.

Post by Glorybx » Sat Nov 21, 2015 1:06 pm

Could it be that the valves are being burnt out. This would explain the difficulty in restarting when hot. Perhaps a compression test would also help here.
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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Sun Nov 22, 2015 7:04 am

Having in the last three weeks replaced the cambelt, I think I would have noticed any lack of compression whilst turning it over to get the timing marks aligned.... :wink:

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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Sun Nov 22, 2015 3:59 pm

Having now done a bit of substitution therapy..... :wink: it's turned out that the starter motor/or solenoid on the starter was the fault. Valeo DR6A, yet to take it apart, though I did not like the bare wires exposed in the feed to the solenoid - the one that also goes to the alternator. I replaced the brushes on this repaired/replacement motor so hopefully good for a while.
So having done the ignition switch earlier at least that got a good clean a lot of metal filings in it!!!! I substituted just the wire feeds so had the steering lock part off and that's where the filings were.

Will feed back if semi hot starting is solved, I suspect it is.

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Re: Hot engine won't re-start 'till cool again.

Post by Tinkley » Fri Nov 27, 2015 7:15 pm

I am fairly sure I've nailed my beast - coil to distributor HT lead. Not that old, and I do change them about every 25k. Anyway when I inspected all the lead ends, the one attached to the distributor cap was definitely past best. Considering I changed the d/cap and rotor arm, and plugs about three months ago, it shows how fast these thing can deteriorate, as I checked the leads then. Bosch leads FWIW.
Donkeys ago had the same main lead go on my old Sumbeam after driving down to Lymington, went sailing all day came back and dead as a dodo for starting. Generally I've been pretty hot on these with the BXs' and the 14 (150C engine) used to go through them at a great rate. However the 1.6s' seem to last better but long enough to corrode in place.

So I would advise changing the set actually Peter. As the 14 used to break the carbon internals whilst still showing perfect ends do not ignore that. I don't know about the valver distributor cap and ignition but that would be my next port of call, followed by the coil.