russ Posted October 11, 2018 Report Share Posted October 11, 2018 Hi, I have a 1965 vitesse 6 that is running on 5 cylinders. I have changed plugs, leads, distributor cap and rotor arm. I have done a wet and dry compression test and all is good. The next thing to do is remove the head unless anyone has got any ideas? Would the piston come out top or bottom without removing the engine? Yours hopefully Russ Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 11, 2018 Report Share Posted October 11, 2018 If the comp test was good why would want to strip the pistons or head off??? I would look at inlet manifold air leaks, worn distirbutor spindle causing cam, wobble statr with the easy Check the rockers are all ok , no jumped push rods or tight tappet clearances and never forget the ...... spark plug Pete Link to comment Share on other sites More sharing options...
russ Posted October 11, 2018 Author Report Share Posted October 11, 2018 Thanks Pete. Air leak check was ok, tappets adjusted and plugs changed more than twice. I was thinking a piston ring had broken. Running out of ideas. Russ Link to comment Share on other sites More sharing options...
poppyman Posted October 11, 2018 Report Share Posted October 11, 2018 I would start by pulling the plug leads off one at time while the engine is running to find out which cyl the problem is on, and go from there. Tony. 1 Link to comment Share on other sites More sharing options...
68vitesse Posted October 12, 2018 Report Share Posted October 12, 2018 Never trust new parts to be good, identify bad cylinder as suggested by Poppyman. Then rotate the distributor by at least one cylinders worth of timing move the plug leads to correct the firing order and see if the fault moves, if it does fault is electrical if not mechanical. Also move plug in duff cylinder and swop its lead object is to move all ignition components. Regards Paul Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 12, 2018 Report Share Posted October 12, 2018 is this a 'complete' non fire on no 5 or a half hearted mis a ring wont cause a full misfire , and if compressions are all good then the internals should be considered to be basically functional are the rockers all fully depressing.......like a cam lobe has done a runner was the compression test all plugs out and throttles open ??? Pete Link to comment Share on other sites More sharing options...
JohnD Posted October 12, 2018 Report Share Posted October 12, 2018 "When you have eliminated the impossible whatever remains, however improbable, must be the truth" Compression test OK (details would be good) New ignition parts So what's left? Fuelling. Have you looked into the inlet manifold? Mouse's nest?? Some other reason for the wrong mixture getting to the cylinder? Which one is it? John Link to comment Share on other sites More sharing options...
NonMember Posted October 12, 2018 Report Share Posted October 12, 2018 One of my former colleagues came along to the Cambridge area meeting in July with a TR3 that was running on three cylinders. Compression all good, sparks apparently good, new points, condenser, leads, disi cap. He'd already checked that swapping leads and plugs left the problem on the same cylinder. On closer inspection, he'd set the points gap so small that the one ever-so-slightly flat lobe on the distributor shaft was not opening them. Re-set the points and voila! a very happy engine running on all four. 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 12, 2018 Report Share Posted October 12, 2018 Same reason as suggesting dizzy spindle wear earlier Delco are more prone to the centre spindle and bush wearing due to lack of lubrication, lucas are less prone but all need a Squirt of engine oil down below the base plate to lubricate the top bush, some have a felt pad down in the base , its often ignored in any Servicing and youmcan end up with a wobbly cam and ever changing point gaps as it rotates So remove cap and give the rotor spindle a good shove , anym side movement is unacceptable. Some electronic units can accomodate some wear, but points cant Pete Link to comment Share on other sites More sharing options...
poppyman Posted October 12, 2018 Report Share Posted October 12, 2018 Setting points with a dwell meter always helps if there is slight wear in the dizzy. Also enables timing to be set spot on. Tony. 1 Link to comment Share on other sites More sharing options...
russ Posted October 13, 2018 Author Report Share Posted October 13, 2018 It is number 6 that is not firing and it is pretty constant. I will try the distributor tomorrow and check the points. Thank you all for your help. Russ Link to comment Share on other sites More sharing options...
russ Posted October 14, 2018 Author Report Share Posted October 14, 2018 Checked the distributor today and there isn't any wear, all plugs firing. Number 6 is oily though but all the valves are seating correctly. Compression test showed slightly higher in number 6. Also did an air leak test on 6 and could hear some leak through the dipstick. What else can I do? Russ Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 15, 2018 Report Share Posted October 15, 2018 have a look at the protrude of the valve guide through the no6 valve springs has one moved about /become loose ??? this can let air in when you dont want it Pete Link to comment Share on other sites More sharing options...
Nick Jones Posted October 15, 2018 Report Share Posted October 15, 2018 You'll always get a bit of leakage past the rings. If the compression is the same as the others, loss of compression is not the reason for not firing (anything over about 50 psi will fire) and the oily looking plug is more likely the result of not firing than the cause. Worth whipping the rocker box off and checking that the valves are moving about the same amount on no 6 as the others. Very little lift on the exhaust valve (due to worn cam lobe) won't prevent a decent compression reading but will prevent that cylinder breathing. Other than that, does no.6 plug get wet with fuel? Have you tried swapping plugs between cylinders or at least a different plug in 6? Nick Link to comment Share on other sites More sharing options...
poppyman Posted October 15, 2018 Report Share Posted October 15, 2018 As above, but swap a lead as well if you can. Tony. 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 15, 2018 Report Share Posted October 15, 2018 And Have you double checked the firing order 15 36 24 anticlockwise in the dizzy cap Link to comment Share on other sites More sharing options...
russ Posted October 15, 2018 Author Report Share Posted October 15, 2018 I have swapped plugs and leads about to no avail. The wetness is definitely oil not petrol and the firing order is correct. I will check the valves as soon as I can. Thanks again. Russ Link to comment Share on other sites More sharing options...
dougbgt6 Posted October 15, 2018 Report Share Posted October 15, 2018 Russ, OK, timing is correct and spark is there. And No.6 has better compression than the rest, the plug should be dripping in fuel. Why is it not? An air leak on the manifold around No.6 would do this, sucking in air instead of fuel. I would look at the manifold gasket again. How did you check it last time? You can't see the underside? Doug Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 17, 2018 Report Share Posted October 17, 2018 Amd ch eck the fixing bolts are not siezed rather than tight. Are all the mk1 type doubled clamps in place Some mainfold gaskets were badly cut and ports and fixing holes were misaligned Pete Link to comment Share on other sites More sharing options...
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