Gritpipe Posted April 23, 2021 Report Share Posted April 23, 2021 Hello all I have a 57 TR3, which has passed five MOT’s since being put back on the road, but what should have been a time of joyful motoring has been one of uncertainty and frustration. I would appreciate some advice please. It has rebuilt H6 carbs, the originally new ignition components have all been changed during the problems and it has been retimed at least twice, it has been set up on a rolling road and on a good day it may do 50 miles or so, on a bad day absolutely nothing. Too much of a risk leaving the garage! There is always fuel at the carbs, I have tried various plug type and makes, currently on standard NGK, although have had hotter plugs in it. It is currently running without an electronic ignition. So, the car may the car may start on full choke but not want to tick over when warmed up, just cut out, it may not start at all, or start and run, warm up but then cut out under load, the fuel pump works well, I run on BP posh e5 and have just started to try the Castrol E5 additive. We are going to give the carbs another inspection, but there are really no clear indicators of where the fault may lie. I have wondered whether to try a set of new HS6 but that me be a lot of money and faff for nothing. Sorry this is a bit long winded. Many thanks in anticipation. I should add the car is now fitted with K n N filters not the trumpets, they went on ebay! Quote Link to post Share on other sites
RogerH Posted April 23, 2021 Report Share Posted April 23, 2021 Hi GP, welcome to the forum. I assume that the dash pots on the carbs have oil in. I had a serious intermittent fault with my dizzy. The very flexible braided wire coming of the contact breaker had come away from its ring terminal. It looked perfect but the solder had lifted away. I moved away from NGK plugs (too many fakes) as their life was too short before causing issues. I now use Champion L87 I'm sure others will add to the list Roger Quote Link to post Share on other sites
Gritpipe Posted April 23, 2021 Author Report Share Posted April 23, 2021 Thank you Roger, yes the dashpot currently has SAE30 although I have tried 20 as well, I will check the flexiwire tomorrow or Sunday. It has been bewildering, just when it seems to have been cracked, a new variant appears, now where have we heard that before. Quote Link to post Share on other sites
barrytr4 Posted April 24, 2021 Report Share Posted April 24, 2021 Hi Grit to me it sound fuel supply issue, "I wouldn't rely at Fuel at carb's", I would recheck all components again ? , Something floating in fuel tank?,,make sure the fuel supply is OK, L/pump, pressure / vacuum w/ a gauge and then flow, , fuel line may part blocked , also rotor arms can pack-up--barry Quote Link to post Share on other sites
2long Posted April 24, 2021 Report Share Posted April 24, 2021 I would make sure all grounds and engine ground strap are good and make sure rust or sediment from fuel tank is not moving up the line. Dan Quote Link to post Share on other sites
John Reilly Posted April 24, 2021 Report Share Posted April 24, 2021 It looks like you have rebuilt the engine, is the standard cam still in the engine or have you changed it? New cam may require its own specific timing and may not be the same as the original. Also unlikely, but check your fuel tank vent is clear. This would cause problems but generally after some milage as vacuum in tank builds up. J Quote Link to post Share on other sites
BlueTR3A-5EKT Posted April 24, 2021 Report Share Posted April 24, 2021 (edited) Did the rolling road operator make any remarks when it was set up? Positive or negative earth battery connection to the body/chassis? Is the low tension wiring of the coil connected the right way? Is it a new coil? Hamish had an issue with his car not revving. That turned out to be the inside of the rubber fuel line connections had collapsed/degraded. Are your tank to carb lines full bore all the way? As John has remarked - fuel vent perhaps. Is your engine a rebuild? Is the top dead centre mark on the crank pulley in the right place in relation to the piston of no1 being at top dead centre? Easy check with plug out. Timing the engine with the timing mark at least 60 degrees out is a known engine rebuild mistake due to the pulley being reassembled wrongly. Edited April 24, 2021 by BlueTR3A-5EKT Quote Link to post Share on other sites
ijonsson Posted April 24, 2021 Report Share Posted April 24, 2021 My guess is also electrics and would like to add a check of the HT leads to plugs and coil (not the same symptoms, but myself I changed back to copper core wires) Quote Link to post Share on other sites
Hamish Posted April 24, 2021 Report Share Posted April 24, 2021 (edited) Pete is correct with my fuelling issues. the rubber joining pipe near the rear wheel didn’t manifest itself on rolling road nor revving the ar#e off it stationary but did running. I used an elec tyre inflator to blow the fuel line back from engine bay to tank that allowed me to finish an event successfully. See here but it was traced to a 50pemce bit of pipe See pic same for tr3s and TR4 s we went though all the ignition electrics before moving to possible fuel issues I had a mechanical pump fail on an event and the whole TR class in the paddock thought it was elec. I now have an elec pump and new hoses and I still had a missfire at my last sprint but that cleared itself that I think is elec - plug leads / dizzy rig up a small tank (eg lawn mower tank) and new fuel pipe and elec pump huco https://www.dellorto.co.uk/shop/car-accessories/fuel-pumps-regulators-accessories/fuel-pumps-carburettor/huco-low-pressure-12v-fuel-pump-133010/ great for twin SU and doesn’t need a pressure regulator a £70 experiment that is cheaper than new carbs and you can keep it on or use as a back up. There again it could be a coil slowly dying ???!!! Edited April 24, 2021 by Hamish Quote Link to post Share on other sites
RobH Posted April 24, 2021 Report Share Posted April 24, 2021 I must agree this does sound like fuel - the dying on load in particular and the fact that sometimes it runs with the choke out but won't idle once it's hot. However as the old saying goes, 90% of fuel problems are electric..... You say you have replaced all of the ignition components - does that include the condenser in the distributor? You also say the fuel pump works well - how do you know that? Is there an in-line fuel filter between the pump and the carbs? - certain types of those have been known to cause problems. Incidentally there are some mods obvious from the photos - like the electrical box on the bulkhead to the right of the battery and that sensor(?) to the left of the thermostat housing. Probably not pertinent to the fault but what are they? Quote Link to post Share on other sites
Adrian Fuller Posted April 24, 2021 Report Share Posted April 24, 2021 I had a similar issue with an Austin 8, turned out to be an intermittent bad earth on distributor / points backing plate. You can connect a very thin wire to the backing plate mounting screw and run out of the distributor onto a good earth. Very quick and easy to do and at least you then know its not a distributor earth problem. Good luck Quote Link to post Share on other sites
keith1948 Posted April 24, 2021 Report Share Posted April 24, 2021 Reading experience of Hamish above is why I have replaced original fuel line on my 4A for a single pipe with no rubber connectors under the car. Years ago my father had a Triumph Vitesse that also had rubber connectors on the fuel line. When the copper pipe had been pushed into the rubber pipe it had peeled off a piece of rubber inside and this acted like a one-way flap valve reducing the flow of petrol from the tank. Took the garage a while to find that fault. As for intermittent running etc, one of my friends with a 3A had a similar problem caused by 'bad' petrol from a supermarket garage in Wales. I filled up at the same time there and also experienced misfiring, rough running and idle etc. Fresh fuel from a different garage and the problem disappeared for both cars. My car runs perfectly well on standard 5% ethanol fuel with no additives (I had hardened valve seats on it 30 years ago). It doesn't like the higher octane fuels. Keith Quote Link to post Share on other sites
Ralph Whitaker Posted April 25, 2021 Report Share Posted April 25, 2021 19 hours ago, keith1948 said: . My car runs perfectly well on standard 5% ethanol fuel with no additives (I had hardened valve seats on it 30 years ago). It doesn't like the higher octane fuels. Keith What is the reccomended octane fuel for a TR4 engine, I am currently using Supreme unleaded 97 octane. 21 hours ago, RobH said: Incidentally there are some mods obvious from the photos - like the electrical box on the bulkhead to the right of the battery and that sensor(?) to the left of the thermostat housing. Probably not pertinent to the fault but what are they? Rob, don`t know about the electrics, but I think what looks like a sensor on the left of the thermostat housing is the bulb on an original copper advance/retard pipe. Ralph Quote Link to post Share on other sites
RobH Posted April 25, 2021 Report Share Posted April 25, 2021 Ah yes. Thanks Ralph. Quote Link to post Share on other sites
Gritpipe Posted April 26, 2021 Author Report Share Posted April 26, 2021 Hello all, May I thank you all for your opinions and help. It does through up the question, when you read all the varied problems us "old car" guys have had as to why do we do it? That said with much affection, mine stems from my dad and Bert "next door" with their cars, however their's were with the family car at the time (so if they didn't work, you didn't go out) Austin 7's and 10's, 100 E Anglia, Vitesse etc etc, mine have been Karmann convertible and saloon beetles, various MG's, Triumphs etc. So, as I was doing the rebuild I made a few changes that appealed to me as I went along. The TR has an SU pump fitted just after the tank (yes I know), straight copper fuel line to a fuel filter on the scuttle, any rubber hosing used is safe for Ethonal, the old cork filled petrol tap is now only for show and is soldered open ( I do also have an original newly corked but still leaky tap), there is a fuel tap at the base of the tank. The tank is ally and perfectly clean, the car has only had BP fuel in it from the same garage near Newport Pagnell. The extra fuse box on the scuttle is for the head lamps etc, the front apron has a multiblock connector so it could be removed with all electrical connections to the lamps still in place for convenience if this was ever required. The distributor components are all from The Distributor Doctor, however I do wonder if the is an intermittent poor earth or power connection so will work my way though these looking for dry joints etc. The carbs have "stay up" floats. Thank you all once again. I will advise of progress. Keep safe. Quote Link to post Share on other sites
Mick Forey Posted April 26, 2021 Report Share Posted April 26, 2021 An alternative method of fault finding is to find somebody locally with the same engine that runs well and start swapping one component at a time between the two cars until you move the problem over to the other car. It maybe a combination of things so do this cumulatively. Start with the easy ones like dizzy cap and leads, rotor arm, capacitor. You can also check the set up using the same set of tools including timing light, colourtune, carb balancer etc. This can also identify differences which may or may not explain the issue. The club has 51 local groups around the country, contact your local group and you will probably find a friendly member willing to help you out. Join the club here: https://www.tr-register.co.uk/ under membership. Mick Quote Link to post Share on other sites
Gritpipe Posted May 3, 2021 Author Report Share Posted May 3, 2021 Good morning all, "The story so far" continuing the saga. W have cleaned and checked the carbs, The choke linkage occasionally allows the forward choke to not return properly to the base of the carb and was upsetting the balance, despite strong return springs. This has been adjusted and hopefully has cured that. However the carbs are now cleaned set and balanced. We ( friend with classic car interests in our village) have have change to a new set of Champion plugs, done a compression test, changed the coil, checked all the leads and supply to the coil, there is deifinatly fuel at the carbs at all times. The battery is relatively new and has had an easy life so far and is fully charged on a slow charge, ( I am not mad on these trickle charge permanently connected battery conditioners). Anyway last Tuesday it fired we set it to a sweet tickover and takeing a change of undies did a very nice smooth circuit of the village, great. Next day tried a test start not a dickie bird, engine turned over but not signs of lif, despite power at all points on the circuits.. Have now got a set of wired leads to replace the nice blue silicone ones, and then we will start again. Have a different distributor to try and yet another coil, the ignition switch seems ok too. Will keep you informed. Thanks again for all your previous contributions. Quote Link to post Share on other sites
RobH Posted May 3, 2021 Report Share Posted May 3, 2021 (edited) Just a thought. Starting from cold can be iffy on a '3 if you don't have the choke fully out. The choke linkage arrangement isn't the best and It is surprising just how hard you have to pull on it and also how far out it comes. It also seems to tighten up so you think it is there but in fact there is more to come, and it's the last bit that does the trick. Full choke is with the knob about an inch-and-a-half out from the dash. Edited May 3, 2021 by RobH typo Quote Link to post Share on other sites
Richardtr3a Posted May 3, 2021 Report Share Posted May 3, 2021 I had some problems like this as well. I bought a tank full of petrol, at a country garage where I had my last MoT some years ago. Immediately the engine ran rough and it was difficult to drive back up the hill to the garage, Fourways Garage Chalford, near Minchinhampton. I tried an additive but it ran badly all the way to Classic Le Mans. It was only on the way home that it began to run well. It was over 700 miles before any improvement. The choke is well known for being difficult. I moved the knob on to the main dashboard so that it was a straight run to the carbs and no longer had to wind round the heater. It is only connected to the front carb and is still much too hard unless I remove the outer cable from the clip just before the connector to the jet. It now works smoothly but does not lock as originally designed but I have the factory issued, Stanpart , wooden clothes peg which works very well. I do not understand how a small curve in the outer cable can make the inner so difficult to move. New cables are expensive as well. If you bought the DD parts for the ignition you should be OK. The small push-on cable to the side of the distributor can get oiled up and dirty making a weak connection. I bought a racing condenser for mini-minors ,£36.00 , which is mounted on the coils fixing bolts and hot starting is now instant. Good luck and keep trying. There are many Tr owners out there who drive with confidence that the car will get them home Richard & B Quote Link to post Share on other sites
Peter Cobbold Posted May 3, 2021 Report Share Posted May 3, 2021 Braided engine earth to body: insulated by paint ? Quote Link to post Share on other sites
billy l Posted May 4, 2021 Report Share Posted May 4, 2021 Hi Gp, apologies if you have tried this before but to eliminate any potential wiring problem, try disconnecting the ignition feed wire from the coil and tape it up to prevent shorting,then fit a jumper wire from battery live terminal direct to ignition side of coil and start engine by pressing solenoide and see how it runs. to stop the engine just remove the wire from the battery. hope this helps, Cheers, Bill. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.