Cutting Out ?

[Triumphcrazy]

Help needed !
Have a 77 stag which after a lay up cut out after less than a one mile journey and would not restart , fiddled with all the usual connections for a about 20mins and eventually restarted to limp home the same short distance to home and again cut out . replaced ht leads /cap and plugs , replace ign coil with intermotor 11070 , cleaned starter motor connections which were corroded , checked and cleaned intertia switch and lumenition 3x pin connector , fuel pump working electronic type, alternator charging at 14.02 volts . will start from cold and warm up for 10-15 mins and cut out , usually after blipping throttle , try to restart long cranking but no firing , battery then fades , managed to restart with boost pack to battery but symptoms persist ? p.s base plate earth lead poor condition but intact not sure how crucial this is , need to change but someone has mullered the ba screws !! whats your thoughts guys ? Lloyd.

[71Stag]

Off the top of my head Has it got fresh fuel in it unleaded can go off in as little as three months and have you checked whether there's any oil in the dash pots and also change the fuel filter.
Cheers
Bruce

[ChasR]

The iffy earth strap in the dizzy would not help, but it would pay to possibly change it so as to rule it out(I have run with suspect looking ones before with no ill effects ).

Have you seen whether the car has a strong spark when the car struggles to restart?

[Triumphcrazy]

Off the top of my head Has it got fresh fuel in it unleaded can go off in as little as three months and have you checked whether there's any oil in the dash pots and also change the fuel filter.
Cheers
Bruce

Thanks Bruce ,
Yeah fuel fresh and filter clean , Lloyd.

[Triumphcrazy]

will try to replace earth as you say to eliminate , spark nice and blue ?

[Ian Durrant]

It could be flooding, after a layup the carb can get varnishes inside that make the needle valves stick and on mine after a long layup I found a rusty looking dust in the area of the needle valves. A good wash of the valves in reddex mixed with petrol and a new filter and blow through and it was a different car.

[Triumphcrazy]

Thanks Ian ,
That may be worth a look !

[grumpy2]

How hot is the coil when it stops?

I had an MG which would stop after about 20 mins and then run rough if at all until cold again. Turned out that a PO had wired a 6v coil into a 12v source so making it over heat. I think your car should have a 6v coil so check the running voltage is less than 9v

Just a thought

Gary

[Triumphcrazy]

Hi Gary ,
The coil is quite warm , I have mounted higher than the previous coil and as you say the previous owner had had optronic fitted and a powertrain coil fitted which was unmarked although prior to this fault ran reliably ? , I have a lumenition mega spark coil as a spare with ballast resistor but unsure of fitting due to the confusion on ballast wire in loom on mk 2 which appears in tact , the intermotor unit is a ballast coil and appears by other posts to be 12 volt , not sure where to go next ? Lloyd.

[Ian Durrant]

Hi Lloyd,

Its either a ballast coil or its a 12v, it can't be both. Besides you say the spark is good when its not starting and since you need two things, spark and fuel, for an engine to start, I think you need to start looking at the fuel system in more depth.

[Delayed Steve]

I'd go for the fuel mate , I have this problem every March/ April and a fill up with fresh fuel nearly always cures it . I know I should drain the fuel off but it ends up being a "I'll do it next week" kind of job .

[Triumphcrazy]

it starts readily from cold and runs fine until cuts out , then unable to restart , i will visit the carbs as you suggest , not sure about your coil definition , all major suppliers list 12 volt ballasted coils for use with ballast resistor , including intermotor 11070 , e j ward list their coil in pic as 12 volt ballast coil stamped on unit , my only query is is wether to add supplied ballast resistor or just use with ballast wire in loom ? Regards Lloyd.

[Triumphcrazy]

ill check out the fuel , thanks Lloyd .

[Ian Durrant]

A coil intended for a ballasted 12v system is a 6v coil, but the suppliers may be (incorrectly) stating that its a ballasted 12v coil because its designed for a system that's otherwise 12v. On a Mk2 stag the ballast is, as you say, built into the loom. You do not need to add a ballast resistor.

The reason I think it *might* be flooding is that flooding makes the mixture too rich and this is less of an issue on a cold engine compared to a warm one. Also you say it often cuts out after you blip the throttle. I have seen fuel pool in the inlet manifold when the needle valves are leaking as there is insufficient air velocity to drag it into the engine. I am surmising that when you blip the throttle air velocity increases and drags that fuel into the engine and fouls the plugs causing the engine to stall. once the plugs are fouled it will not restart until the fuel evaporates from the plugs and then the cycle repeats. You seem to have covered everything else and replaced most items. Its the same symptoms as I had on mine after a layup, except on mine it went from started to stalled much quicker but possibly my needle valves were leaking more badly than yours?

[Triumphcrazy]

Thanks Ian , ill check it out and let you know !