Club Triumph

Hi All

Thanks for reading! this is bit of a long post but I'm out of ideas and short of putting it on a trailer and taking it to the garage I dont know what to do !

My MK1 Gt6 was running fine when I put her away about 4 months ago, I went to move it last week and the engine will turn over but not fire, I did hours of online research, and after checking various suggestions discovered the coil a Flamethrower 1.5ohm ohm was getting very hot.

The coil was a 1.5 ohm meant I believe for a ballast resistor ignition, I have read that the mk1 isn't ballasted and I've checked with the multi meter and there is no resistance which makes me pretty sure the car is unballasted plus there is constant 12v at coil with ignition on 

I've fitted a new lucas 3 ohm coil made no difference

Ive cleaned the carbs they are Stromberg 175 cd fitted by the previous owner years ago, removed the float bowls, checked the floats all ok whilst careful not to move any adjusters, blown air through the shaft that is in the float bowl and the little valve that is shut off via the float, fitted new gaskets too. The diaphragms were only changed last december, I have noticed now that if the car is cranked fuel seeps from where the throttle spindle exits the carbs on both carbs?

Engine still cranks wont fire, some times the starter disengages and sometimes it just keeps turning the engine over. 

Ive fully charged the battery, and checked with multi meter all good.

Ive removed all the plugs checked for spark, all spark ok

Ive tried engine start and sprayed fuel into the carb inlet and nothing just turns.

Yesterday I removed all the plugs cleaned them put them back in again exactly the same, left it for an hour or so tried again it reluctantly started and ran !!! Brilliant I thought until this morning thought Id try it again and nothing just cranking over not firing!!! 

Just to recap after all that !

Plugs have spark 

new coil fitted 

cleaned the carbs

took the fuel line off, fuel is being pumped when cranking over

Fuel now seeping/dripping from where throttle spindle exits the carbs

Using engine start makes no difference 

Car has lumenation electric ignition if this makes a difference?

Any help greatly appreciated as I'm desperatre now!!! really dont want to have to trailer it to my mechanic !

Thankyou 

there are two types of choke  , the choke may not be working fully 

so when  you pull the choke does actually raise the "thames Barrer" ramps on a early CD 

if you have  a starting valve ( normally just on the front carb )  check the disc inside is fully free to turn fully with the cable pull

and the small metering holes in the disc are clear  ( just two screws to look see)

does the 175 have temperature compensators on the sides ???

having a 1,5 ohm coil doubles the HT and current required  this can 

wreck the dizzy cap and rotor insulation 

Pete

Hi Pete

Thanks for getting back to me, Ive added a pic of the carbs the choke cable does lift the arm, not sure if I have a starting valve or compenstors ?

Is there a way of telling if the dizzy cap and rotor arm have been damaged ?

Jason 

Couldn't add an image but if you go to my profile the pic of the carb is there

did it !

Hi, you have the 'thames barrier' type choke so as you look in the mouth of each carb a bar at the bottom should rotate by operating the choke. This bar lays flat with the choke off and the air pistons inside sit down on the base of the 'throat'. Then as the choke is pulled out the bar rotates and lifts the pistons so pulling their needles out of the jets slightly to enrichen the mixture.

You should check the air pistons move freely by lifting them with a finger and releasing so that they fall back with a positive clunk....

If there's fuel dripping from the throttle spindles then it may not be lack of choke at all - you might be flooding it. Try with no choke but a bit of throttle.

hi Rob ive tried with out choke but still the same,

tight wad with regards to lifting air pistons do you mean through the air filter entrance ??

Think Ive just checked the air piston, quite hard to push up and take about 2 to 3 seconds to return to the bottom is this normal ?

yes lift them through the air filter entrance but sorry I should have said undo and remove the dampers which are the black knobs on the top of the carbs. The air pistons should then move much more easily although it does sound like theyre operating correctly.

Have you checked the rotation of the choke bar on each carb and that they lift and drop the air piston correctly?

If your happy the choke is working correctly and not stuck fully on so flooding the engine then it doesnt look like fuel is the problem.

One thing you could check is that each cylinder is producing compression. Remove all spark plugs and while an assistant spins the engine on the starter check that theres a good puff coming from each spark plug hole. After leaving a vehicle a while theres a slight chance that one or more valves have stuck open...

I would have said 3 seconds to drop is rather long, even with the dampers in. Half a second feels more like what I'd expect. What oil do you have in the dampers?

Try loosening the 4 screws holding the dashpot. It is very easy to put the dashpot in the wrong orientation, and usually it is the last of the 4 alternatives you try.

Lots of jumping in the deep end on this problem could it be something as simple as stale fuel?

Thanks everyone really appreciate all the input, and suggestions ill check each one tomorrow after work, what oil is best for the dampers ?? 

Ordinary 20/50 engine oil for the dampers. But Clive and Mark both have good points, too.

Agree with Rutty. You said it was running ok when parked up so can't be much wrong with it. Don't start pulling bits off it especially if you're not sure what you're doing. It does sound like its flooding though so maybe  a bit of rubbish under the float valves.

Tony.

I always try a spray of Quick Start. Then if it starts OK for a few seconds then the ignition side should be ok and start looking at the fueling side. 

Danny

I allways try poping the plugs out cleaning them get the soldering torch out to warm them up and squirt a few cc of petrol in each plug hole pop the plugs in while hot and try again, also pop the dizzy cap and leads in the oven for a few mins to make sure they are not damp ( it helps if the wife is at the hair dressers ) while doing this, 

Hi 

I've just checked that the choke is operating the air valve correctly and it does seem to be, again tried starting it, but just its  continually turning over and not firing. Manaully opening the air valve and throttle gate it appears that there is a pool of fuel just inside the in take manifold. Not sure if this is right and the carbs are also dripping fuel again after cranking it over ?

has fuel gone stale ?

try fresh fuel

Ill give that a try next !