tomopope Posted July 4, 2016 Report Share Posted July 4, 2016 Hi all. First post here, I'm new to this game... Decided to take the plunge and buy a '79 1500, as having always been quite handy I fancied learning about cars... so far it's been a steep curve. The engine was fully rebuilt (for the first time - it's done about 75k miles) by a garage about 100 miles ago (long story - series of cooling issues culminating in blown head gasket, and the rebuild was way beyond my abilities unfortunately). On the drive back, after an hour or so, it started "chugging" at lower revs when hot and I was wondering what I should do to investigate this further. Engine sounds quite "throaty" and will accelerate in jerks. It seems to idle fine. It has had problems with the choke sticking before but I checked and the jet bases were up where they should be, and would have thought a choke issue would have been apparent from the go? Feels like carbs / fuel problem but they're all new systems to me! Where should a newbie who can't afford any more garage bills start looking? All help gratefully received. Cheers Tom 1 Link to comment Share on other sites More sharing options...
TomL Posted July 4, 2016 Report Share Posted July 4, 2016 Hi Tom, Welcome to the forum and to owning a Triumph. Whereabouts are you? Someone from your local area might be able to help. There is a wealth of knowledge there and usually some willing volunteer who'll take a look. Whereas the symptoms you describe might well be carb-related (does sound like fuel starvation), it could also be ignition-related - do you run points-and-condensor or electronic? Regards, Tom Link to comment Share on other sites More sharing options...
tomopope Posted July 4, 2016 Author Report Share Posted July 4, 2016 I'm based in relatively central London (Clapham) unfortunately which does tend to make things more tricky as I'm not 100pc confident it would make a long trip elsewhere at the moment. I did think ignition, it's points and condensor. The garage did say they felt the carbs needed tuning which is why I'm leaning more as a potential problem in that direction. Anything I can do to try and isolate more which system it might be? Thanks. Link to comment Share on other sites More sharing options...
TomL Posted July 4, 2016 Report Share Posted July 4, 2016 When you say it was hot, was it very hot, on the brink of overheating? Did the symptoms disappear when it cooled down? How old are the points and condenser? If they are old or unknown, it might be worth changing them to rule them out. Does the car have "wax stats"? Tom Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 4, 2016 Report Share Posted July 4, 2016 Some thoughts, Youve checked the choke return as its a common culprit, good As much has been disturbed you could have the magic rubber slivers or debris in the supply to the float needles and one is partially blocked If mixture settings are a bit unkown I would take the piston cover off and remove the air piston look at the jet height where it sits in the bridge of the carb throat, the tip of the jet tube wants to be about 2mm down from flush the needles will be biased , sprung but the fitting should be flush with the base of the air piston Both to be the same , screw the adj nut to make this a base setting , Link to comment Share on other sites More sharing options...
tomopope Posted July 4, 2016 Author Report Share Posted July 4, 2016 Tom: Nope, the temperature was normal - middle of the gauge. I need to try it again tonight to see if it's better now it's cooled. No idea how old the ignition system is unfortunately - definitely not been replaced in the last few years and may be much earlier. Worth going over? Yep - mechanical thermostat. I'm loathe to touch the cooling side though since the temperature was normal - or am I missing something? Pete: Thanks for chiming in. OK I'll give this a go, might need to come back to you if I can't figure it out. Link to comment Share on other sites More sharing options...
JohnD Posted July 4, 2016 Report Share Posted July 4, 2016 "Chugging"? Was this to describe the noise or the ride? Was it 'pogoing', leaping forward, then almost stalling or just making a funny noise? It's difficult to describe the latter. Have you looked at this website's front page for "Area Directory", where and when the local groups meet? There are several in the South East, so pick one, ring the Area Organiser to confirm the venue and get along. It'll be nice and warm and "chugging" when you get there! But hearing/seeing the patient helps the diagnosis! John Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 4, 2016 Report Share Posted July 4, 2016 If you get stuck would she chug to sunny Luton ? we have fixed a number of london based cars that drive up and expire on the drive pete Link to comment Share on other sites More sharing options...
Mjit Posted July 5, 2016 Report Share Posted July 5, 2016 Do you have the heat shield fitted between the carbs and the inlet manifold? Had something that could be described as "chugging" at low RPM on my car. Would start out fine but after a while would struggle to run at lower RPM but fine higher up the rev range, with the minimum RPM going up over time. Stop for 5min and it would be fine when I set off but slowly issue would come back. In my case it turned out to be temps under the bonnet - but not in the cooling system (gauge was always well behaved) or air temp (would happen on UK in March) - leading to fuel vaporisation. Fitted a heat shield and not happened since. 1 Link to comment Share on other sites More sharing options...
tomopope Posted July 5, 2016 Author Report Share Posted July 5, 2016 It is hard to describe - I went for a drive last night and it was initially fine, but once up to temperature (15 mins or so) the chugging was back, although not as dramatically as before (after an hour or two on the motorway). It's best described as a jerky acceleration, the car doesn't almost stall. Bit like a bucking bronco. Not sure if it's relevant but the speedo needle will flick about too, about 10mph either side of the speed it should be. Low revs only. Mjit - that sounds like a very similar problem although I do have the heat shield fitted... I think next step is to take a look in the carbs and then to Pete or one of the local meets for an in-person diagnosis... Thanks all for your input so far, much appreciated. Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 5, 2016 Report Share Posted July 5, 2016 Check the little braided wire that earths the dizzy moving plate to the case is sound is the condenser tight check the coil ign feed is on the +ve and the dizzy is on the -ve pete Link to comment Share on other sites More sharing options...
JohnD Posted July 6, 2016 Report Share Posted July 6, 2016 Like Pete, this sounds more ignition than fuel. Tell us about the ignition system. John Link to comment Share on other sites More sharing options...
TomL Posted July 9, 2016 Report Share Posted July 9, 2016 Hi Tom, Have you made any progress with your chugging Spitfire? Tom Link to comment Share on other sites More sharing options...
tomopope Posted July 10, 2016 Author Report Share Posted July 10, 2016 Today I investigated the ignition as per pete and john's comments. It's mechanical, lucas 45D4. Pete - checked the earth, condenser and ignition feeds, and all looked good. Had a spare set of plugs so pulled those and replaced, but they came out fine (matt black carbon deposits, but not much). Also had a spare ignition servicing kit from the club shop, so swapped everything over (cap, points, rotor, condenser, leads). Anything else to look for on the bits that came out? Now won't start at all! Fuel's going in and can't see it being a compression issue so I've definitely b****d something up... Will pull the leads and check for a spark as soon as I can (was alone today and my arms aren't long enough!). Will report back when I've done the basic checks. I'm moving house in a week so at least that sets a deadline on when the old thing will need to be able to move... Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 11, 2016 Report Share Posted July 11, 2016 you have probably got the points wired to earth , depends on if they are a terminal post or a clip to fit the wires but revisit what youve replaced . the moving plate earth lead goes on the condensder screw not the points post. if its got a small top hat plastic bush the eyelets go under it not on top of it dont forget firing order is 1342 anticlockwise on the dizzy Link to comment Share on other sites More sharing options...
TomL Posted July 11, 2016 Report Share Posted July 11, 2016 Oh no! I think you're absolutely right to make your next job checking for a spark. Did you set the points as described in the manual? Assuming you don't have a spark, I expect that you'll have to start putting back some of the old bits you've removed and keep on checking for a spark. Tom Link to comment Share on other sites More sharing options...
Mjit Posted July 11, 2016 Report Share Posted July 11, 2016 If you're often working on your own invest in a set of these - http://tinyurl.com/h5bdgz3 I'm in the same boat and found they make life much easier. Only annoyance is that they come in a pack of 4 and you only really need 1. Link to comment Share on other sites More sharing options...
68vitesse Posted July 11, 2016 Report Share Posted July 11, 2016 Never think that as a component is new it isn't faulty. Regards Paul Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 11, 2016 Report Share Posted July 11, 2016 years ago I was engrossed in my office and a particular guy who was a bit ..lets say thick .. always asking how to do things and couldn't get his head round timing, so taking the mick i told him to stick the HT lead in is lips and turn the engine till he felt a jolt next day we had to call security to remove a somewhat irate operator ... well it worked didn't it Pete Link to comment Share on other sites More sharing options...
TomL Posted July 11, 2016 Report Share Posted July 11, 2016 Woah, Pete, I am not sure you should boast about that! The poor guy is probably still in therapy. Also not quite sure how this contributes to the topic. Tom Link to comment Share on other sites More sharing options...
JohnD Posted July 11, 2016 Report Share Posted July 11, 2016 "Matt black plugs"! I withdraw my previous!!! Too rich. Should be tan brown on the electrodes. You're right to go back step by step if it won't start now, AND you have checked the timingn, and lead distribution. John Link to comment Share on other sites More sharing options...
tomopope Posted July 12, 2016 Author Report Share Posted July 12, 2016 That's tonight's job... Thanks all, will report back. Leads definitely in the right order so something's not making the right contact somewhere / dodgy earths / dodgy bits. John - here's a photo - they weren't too black - what do you think? Link to comment Share on other sites More sharing options...
JohnD Posted July 12, 2016 Report Share Posted July 12, 2016 Tan brown electrode - correct mixture! I retract my retraction! JOhn Link to comment Share on other sites More sharing options...
tomopope Posted July 12, 2016 Author Report Share Posted July 12, 2016 Sorry for a misleading description John! Right, now I'm totally stumped. - Checked for spark. No spark - Resistance tested the coil. 1.5 ohm across the outside and 8.6k from the middle to the outside. It's getting 12v. That seems OK? - Put the old condenser, points, cap and rotor on one by one and no change - Swapped the leads for new ones for good measure. Definitely in the right order. No change - Checked for spark again. Still no spark What can I test now? All fingers pointing to the distributor? What might I have put back wrongly (there's not much to go wrong..!) or can I test to try and narrow it down? Here are a couple of pics in case that helps (when old gear back in). Link to comment Share on other sites More sharing options...
JohnD Posted July 12, 2016 Report Share Posted July 12, 2016 Get out your multimeter Look for a voltage that goes 12V (approx) to zero at the coil when the CBs open. OR Fit up a plug on the engine where you can see the spark gap, Wire loop around it on a metal bit. Put the King Lead (Coil to dizzy) on it and fit a lead from the coil direct to the battery, and a nother to the earth Make and break the battery lead, and see if your lash-up plug has a spark. If not, coil bust. JOhn Link to comment Share on other sites More sharing options...
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