Guest Alfaguy Posted March 20, 2006 Report Share Posted March 20, 2006 Hi My first post - just discovered this site which looks great. I had my TR6 out today - the first time this year with the roof down and I stopped at a shop and when I got back in it - it would not start. This is a long time problem with this car but I don't know what's causing it? It starts fine when cold and as long as you don't drive it too far (hence does not get too hot) it will perform great. However if you stop it at all when hot you can forget about starting it again until its cold? Can some one give me some ideas as to what to do - I am at my wits end over this as my precious TR6 was stranded outside this shop for most of the evening. (I should have left it in the garage of course - it being a national holiday weekend here over flippin St Patrick. I think it is an ignition related problem as there is no spark to the plugs at all when it is hot. I have switched coil's a few times with no improvement. Its not related to hot weather as it can happen in all temperatures. I am not too well up on cars but do all my own basic servicing. I am afraid to give my TR6 to any mechanic as if they start messing with the PI fuel injection system its a ship to the UK job to get fixed. Quote Link to post Share on other sites
JohnC Posted March 20, 2006 Report Share Posted March 20, 2006 When you say it won't start when hot, do you mean it will turn over but won't fire? This is a total stab in the dark, but if it runs OK when hot, but refuses to restart when hot, I'd be suspicious of the starter motor connections, the battery, and the +'ve lead to the coil. My reasoning is that there must be something robbing the plugs of juice while starting. Hot wires & connections have more resistance than cold ones, so this just might be the answer. The battery is just another possibility - although I think they're happier when hot rather than cold. If you're mistaken about the total lack of spark, then I'd look at the wiring to the fuel pump. This subject has been discussed ad nauseam, but if this wiring is substandard then it will heat up in use; resistance will rise, and combined with the reduced voltage available when cranking the starter you'll get no petrol through the injectors. So, my suggestion is to first check the starter motor connections and the ignition coil feed. If you don't find the problem that way, then check the injectors for proper spray pattern when the engine is refusing to start (do a search in the forum for loads of info on this). Good luck, John Quote Link to post Share on other sites
jerrytr5 Posted March 20, 2006 Report Share Posted March 20, 2006 There were (probably still are) a bad batch of rotor arms floating around that would earth out through the dizzy when hot. I had one on my 5 that took me about 6 months to track down and it took a rolling road session to locate it. In my case it showed as an intermittent misfire when hot but it's possible it could cause a complete ignition failure. Try and locate a Lucas one and try it, or borrow a known good one and see if it makes any difference. Other possibilities would be cracked dizzy cap or dodgy HT lead. Quote Link to post Share on other sites
Roger H Posted March 20, 2006 Report Share Posted March 20, 2006 "I think it is an ignition related problem as there is no spark to the plugs at all when it is hot" Have you checked the plugs out of the engine when hot? If you have spark, then read on.....! Does it start after a while and is there a smell of unburnt fuel? - They can be a pig to start if you have leaking injector seals which drip fuel into the manifolds and cause flooding. When it doesn't start immediately, there is a tendency to think it's because of too little fuel and you put the boot in - then it overfuels and the problem persists with the plugs starting to foul, particularly if you are running a bit rich anyhow. The fact that it starts easily when cold could indicate it's too rich? - do you use full / half choke when cold? See if it starts easily at 30 seconds after switching off hot - if it does, leave it a minute and try again. If OK, leave it 2 minutes etc etc till you find that it's not starting at (say) 5 minutes. If it gets progressively worse, start looking more closely at the fuel system rather than the ignition. Quote Link to post Share on other sites
Richard Crawley Posted March 20, 2006 Report Share Posted March 20, 2006 Hi Alfaguy Welcome to the forum. My first advice is don’t start messing with the PI system until you have read previous posts & all the available documentation & if leaving it to someone else, only let one of the specialists loose on it. The Lucas PI system is very simple but you need have to a good understanding of how it works to fix it. Many of the original criticisms about unreliability in the 70’s were down to Sunday afternoon tinkering by those more used to fiddling with carburettors. You need to be really certain it is the electrics so follow Roger’s advice to check for a spark; if there is no spark when hot then it should be easy to fix, just a matter of elimination. What ignition system are you running, standard or electronic? You say you’ve switched coils, have you tried replacing the capacitor? Does it run perfectly up until you switch it of or does it misfire at all? The 6 is very susceptible to the condition of the ignition electrics in performance, reliability & fuel consumption, I don’t have any idea the age/condition of the car but I would replace all the ignition bits if in any doubt & switch to electronic ignition if you can. If it turns out not to be sparks, post again with more detail as it could be down to any number of things! Quote Link to post Share on other sites
Guest Alfaguy Posted March 20, 2006 Report Share Posted March 20, 2006 Thanks guys - I will check out what you all said and get back to you. Quote Link to post Share on other sites
Guest johnbousfield Posted March 22, 2006 Report Share Posted March 22, 2006 I had terrible trouble with hot running, only difference is that I got some warning as it would start running so lumpy that it felt like it was on about 3 cylinders. Tried everything suggested by many people on this site (I'm not that expert myself, just 'part time' competent). It certainly wouldn't have started again had I stopped it anyway! Always suspected electrics and started swapping stuff around and also noticed an article re Dist Caps and Rotor Arms breaking down when hot (even new ones are sometimes dodgy evidently from some suppliers). Swapped leads, condenser, coil, etc. but last change was Cap and Rotor and (touch wood) this made a huge difference. During all of this I noticed that any period of bad running really buggerred up the plugs badly and my car certainly is hopeless without clean plugs for some reason - so (for me at least) I always keep them perfect now. Other suggestions I had were injection (including the 'choke' not returning properly and vaporisation and/or old lucas pump), hoses (pressure problems affecting dist and/or injection system), any/all electrics you can think of. Summary :- Slightly different problems I know but sounds like elecs breaking down somewhere to me; replace all the HT stuff (quite cheap), but for me it was Plugs, Dist Cap, Rotor!!! Good luck, John (PS where are you in the country?) Quote Link to post Share on other sites
Richard Crawley Posted March 22, 2006 Report Share Posted March 22, 2006 replace all the HT stuff (quite cheap), but for me it was Plugs, Dist Cap, Rotor!!! Yes it can make a huge difference; when I used my every day I used to replace the cap, points & rotor every 3K & the plugs every 6K. The car does very few miles these days & I have also gone electronic, which makes a huge difference. Quote Link to post Share on other sites
Guest Alfaguy Posted July 27, 2006 Report Share Posted July 27, 2006 (edited) Sorry for not updating before now but I did what most of you suggested - replaced coil, Ht leads, rotor arm, plugs and condenser and hey - no more hot starting/running issues. Just back from a 3,500 motoring holiday in it which covered the UK, France, Monaco, Italy and Switzerland in heat wave conditions and never had any problems. Well my brakes finally caved in on the final day on the way back to the Euro tunnel but I should have revamped them more for this trip as it involved several jaunts over the Alps. I am located in south West Ireland btw - Tralee, Co Kerry to be precise. Thanks for the advice. Link about my holiday. http://www.octane.ie/cult/forum/showthread.php?t=5260 Edited July 27, 2006 by Alfaguy Quote Link to post Share on other sites
johnmac Posted July 28, 2006 Report Share Posted July 28, 2006 You seem to be fixed now, but for the benifit of others I would confirm very similar problems which were caused by the rotor arm afew years ago. I would breakdown, swap coils and would work, etc, etc. 100% proof of cause as it suddenly failed altogether and was cured instantly by swapping. As an electonics/electrical engineer I was able to check the old one with a"Megger" as used for insulation testing and proved it would short to earth through the centre shaft at "high" voltage (500v). I was disapointed because the original had only lasted 25years! Ironically about a month later my rover 820 did the same thing on the way to work. Quote Link to post Share on other sites
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