SteveT57 Posted April 7, 2021 Report Share Posted April 7, 2021 Hi All I’ve recently joined the TSSC and I’m hoping that someone can assist me. I have a 1969 Vitesse Mk 2 that, as far as I can tell, is pretty standard. However the engine hesitates/surges between 2000 and 3000 RPM, which is most noticeable when accelerating (even gently) in 2nd gear. Also, occasionally when travelling at a contact speed on a flat road, say at 55 MPH, the engine seems to start to loose power for a few seconds and then makes a ‘phutt’ sound, then resumes normal power. I have tried different dashpot oils(3-in-1, SAE 10 and 20-50) but none seems to make any difference. The timing has been checked with a strobe light and it is OK. The ignition advances with increasing revs. New sparkplugs have been fitted. A new fuel pump has been fitted. The points have been replaced with the magnetic sensor set-up, so no condenser needed. I have tried to set the fuel-air mixture using two of the Gunson Colourtune spark plugs in positions 2 and 5, but with little success. The carbs have new diaphragms and O-rings fitted to the main jets. I have followed the manual for the resetting of the main jets using the lifting pins on the carbs., etc. It starts well from cold, but starting can be problematic when the engine is warm. The temperature gauge reads just below the half way mark when fully warmed up. Note: The hesitation is still there when the engine is cold, so it doesn’t seem to be related to the engine temperature. I have searched this forum for ‘misfire’ etc. Thanks in advance. SteveT Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 7, 2021 Report Share Posted April 7, 2021 have a look at the dizzy cap is this a delco dizzy ???? make sure the cap centre contact is actually touching the sprung contact of the rotor arm if its a lucas and the rotor has a rivet in the sweep plate throw it away get a red one from club shop or others what plugs/type are you using ? dashpots are straight 20 or engine oil 20/50 dont mess with others as you have fitted a pump and played with the carbs there is a good chance refitting rubber hoses has made some of the dreaded rubber slivers which float about and jam up the back of the float needle valve ( persistent little sods ) does it have std air filters and air box ?? make sure no filter gaskets are covering any front face holes in the carb any corrosion up the coil HT connection ?? and check the coil polarity ie neg to dizzy white ign to Pos what was the trouble with the colour tune , good result /no result what did the lifting pins show ??? that do for a start Pete Link to comment Share on other sites More sharing options...
SteveT57 Posted April 8, 2021 Author Report Share Posted April 8, 2021 Hi Pete, Thanks for your prompt reply. The distributor rotor arm is the new(red type). Plugs are NGK BP6ES. Air filters are standard. Will check the other points you mentioned also. Thanks again. SteveT Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 8, 2021 Report Share Posted April 8, 2021 just confirm is the dizzy lucas or delco or a n other Pete Link to comment Share on other sites More sharing options...
SteveT57 Posted April 8, 2021 Author Report Share Posted April 8, 2021 Hi Pete, Distributor is a Lucas one. Could the problem also be due to an air leak, carb to manifold etc.? Thanks. Steve T. Link to comment Share on other sites More sharing options...
Steve P Posted April 8, 2021 Report Share Posted April 8, 2021 I would also check the fuel pipes haven`t degraded and are allowing air in somewhere,i had a similar issue on my Herald. Steve Link to comment Share on other sites More sharing options...
daverclasper Posted April 8, 2021 Report Share Posted April 8, 2021 Hi Steve and welcome if your a new member. is it, a recent purchase that is running like this, or something that has developed since your ownership?. Dave Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 8, 2021 Report Share Posted April 8, 2021 Lucky lucas are the best do check the dizzy has a moving plate short braided earth lead to one of the plate fixing screws often these break inside the braiding and you get an intermitent earth always give a squirt of oil under the base plate to oil the top dizzy bearing or it wears out and the shaft wobbles and the gap becomes variable as the cam rotates so give the rotor spindle a good sideways shove , it should not move Pete Link to comment Share on other sites More sharing options...
SteveT57 Posted April 9, 2021 Author Report Share Posted April 9, 2021 Hi Guys, Its probably something I've done. Just after I acquired the car, I found it had a bad oil leak coming from the rear of the cylinder head; while I had the head and carbs off, I replaced the carb O-Rings(that had gone hard and were breaking up) and the diaphragms. Just after that, I found that the fuel pump was sucking in air under the bolt that holds the metal cap on, as I couldn't successfully seal this, I fitted a new pump, along with a new fuel line to the carbs. I also replaced the points with the magnetic sensor setup about the same time, and reset the timing with a strobe light. I also fitted a thermostat as the previous owner hadn't fitted one('It always ran cold', he said). The temperature is now fine and the needle is just below the half-way mark when fully warmed up, but it hesitates/surges when cold also. It's not so serious that I can't drive it, but I am concerned that it's not doing the engine/transmission any good. I will check the distributor and the other suggestions this weekend. Thanks again for your assistance. Steve T Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 9, 2021 Report Share Posted April 9, 2021 another check that the diaphragm location lugs are located in the body and piston undercuts if you remove a top cover and look down the two holes in the bottom of the piston should both be towards the engine pete Link to comment Share on other sites More sharing options...
SteveT57 Posted April 12, 2021 Author Report Share Posted April 12, 2021 Hi Guys, Over the weekend I checked the distributor shaft and there’s virtually no side play and the advance retard mechanism was free to move, but I put a few drops of oil on it anyway. I also dismantled both carbs to check the float needle valves, both were clean, move freely and importantly they sealed well when closed. Jets were clear and I have centralised the main jets and set the jet adjustment back to the default setting(3 turns ACW). Will start it up later this week and try to fine tune the mixture using the lifting pins, etc. Cheers, Steve T Link to comment Share on other sites More sharing options...
SteveT57 Posted April 14, 2021 Author Report Share Posted April 14, 2021 Update: I stripped down the carbs down on the Vitesse at the weekend and re-centralised the main jets, etc. It seem to be going better now (not perfect yet) but the acceleration is now quite good. I took it out this lunchtime for a 20 mile run, so I now need to check the colour of the plugs to see where the mixture is, after I reset everything back to the default settings. It starts easily hot or cold now, so it can't be far away. Link to comment Share on other sites More sharing options...
dougbgt6 Posted April 14, 2021 Report Share Posted April 14, 2021 I read you replaced the diaphragms, were they Durex flimsy? Or the dread elephant condoms? There are some awful spares out there. Did you take the carbs off the head? Manifold gasket leaks can be troublesome. Doug Link to comment Share on other sites More sharing options...
Martin mon Posted April 14, 2021 Report Share Posted April 14, 2021 On 08/04/2021 at 17:28, Steve P said: I would also check the fuel pipes haven`t degraded and are allowing air in somewhere,i had a similar issue on my Herald. Steve Hi Steve, I had right problems setting the carb on my 13/60 could never get it quite right. On your advise checked the fuel line and the rubber pipe before the carb was degraded and letting air in. Replaced that and added an inline filter and it's now perfect. Great post thank you. Cheers Martin Link to comment Share on other sites More sharing options...
SteveT57 Posted April 15, 2021 Author Report Share Posted April 15, 2021 Hi Doug, Interesting that you should mention the thick and useless diaphragms. About 2 years ago I purchase a pair from a very well know Triumph spares supplier and found that they didn't allow the slide to drop down, even with the jet block removed. I measured the new ones and they were 25 thou thick and the originals were only 15 thou thick. The supplier did replace them FOC however. Hi Steve P & Martin, The fuel lines and rubber interconnections have been replaced and there were no signs of any deposits in the float bowels. The hesitation and surging only occurs occasionally now and the car is generally going much better, but I will have another go at the set-up at the weekend. Thanks, Steve T. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 15, 2021 Report Share Posted April 15, 2021 do double check the short hose on top of the tank reserve lever/suction tube out of sight and these can suck air , as the hose ages it wont leak much fuel as its up high but will let air in and starve the pump . Pete Link to comment Share on other sites More sharing options...
SteveT57 Posted April 17, 2021 Author Report Share Posted April 17, 2021 I set the mixture using the carb’s lifting pins and took the Vitesse out for a 20 mile run. It almost ran almost perfectly and only hesitated/surged once when accelerating in 2nd gear. When I got back I turned off the engine, opened the garage door and 5 minutes later it refused to start. Engine turned over fine with the new Bosch battery fitted last year. Any ideas? Is it worth fitting carburettor shields to reduce evaporation of fuel? Thanks, Steve T. Link to comment Share on other sites More sharing options...
johny Posted April 17, 2021 Report Share Posted April 17, 2021 I know youve set the mixture with the pins but its not an exact science so you could richening the mixture a half turn to see if that improves the hot starts. Also have you got recent cylinder compression readings? Link to comment Share on other sites More sharing options...
dougbgt6 Posted April 17, 2021 Report Share Posted April 17, 2021 43 minutes ago, SteveT57 said: Is it worth fitting carburettor shields to reduce evaporation of fuel? Not really, I've been through the hottest of summers in a GT6, a car famed for being on the edge of overheating. it's never happened. It can happen in sunnier climes, but not in UK in April. Doug Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 18, 2021 Report Share Posted April 18, 2021 the misfire /surge does it try to die then give a kick as if trying to speed up ??? or just you get a hic up in the power applied ,does it do it cruising or when demanding more power not starting hot sounds a bit on the rich side Pete Link to comment Share on other sites More sharing options...
johny Posted April 18, 2021 Report Share Posted April 18, 2021 1 hour ago, Pete Lewis said: not starting hot sounds a bit on the rich side Pete Sorry, yes that sounds more like it... Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 18, 2021 Report Share Posted April 18, 2021 24 minutes ago, Badwolf said: Simple layman's terms hic up sort of miss you get when a spark plug is failing you get a short jerk on load ( not the driver) die power drops off you start to panic surge takes off of its own accord you get all excited on choke means you left the handbag hanging on the choke knob does that help Ha Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 18, 2021 Report Share Posted April 18, 2021 sorry its broke !!!!! pete Link to comment Share on other sites More sharing options...
SteveT57 Posted April 18, 2021 Author Report Share Posted April 18, 2021 Hot/warm starting issue: I made another test run today, only about 8 miles this time. When I got back, I turned off the ignition and I was able to restart it immediately, twice. I left it 10 minutes and it refused to start. The carb float bowls and fuel pipe from the pump were only just warm, so its unlikely that it’s fuel evaporation from either of those areas. However the inlet manifold was very hot, so I got some damp rags and put them on the manifold to cool it down, but it still refused to start for almost 2 hours. Spark plugs looked OK, perhaps a bit on the rich side, so have screwed in the main jets by ½ a turn to lean the mixture. I will try another run this week Frustrated of Rutland. Steve T. Link to comment Share on other sites More sharing options...
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