ignition coil issues

[ajm]

hi,

my stag has issues with the ignition coil breaking down when it's getting hot (eg after 40 miles.) it was normally boltedbetween the vee,in this position,and with a sharp throttle opening it loses the spark as the engine falters,this was proven with the aid of a inductive strobe light.with a steady thottle opening it's ok.the problem only occurs when the coil is hot.

so I temporarily repositioned the coil on the bulkhead and went for a drive andthere is a vast improvement.has any body else had this problem? I have bought 2 new coils with the same result.

I am using piranha electronic ignition what is the correct coil to use for this?

i have unipart plugs fitted,could this cause a problem?

shouldI bolt the coil to the bulkhead permanently?

any suggestions?

cheers

allan.

[GDPR]

imported post

If it works for you Alan.....ultimately you are the one that will break down.....

I would be inclined to disconnect the vacuum advance pipe and then try the snap test again - it could be the wiring on the baseplate is faulty and you get a fault in the trigger lead when the vacuum unit moves it....

Russ:dude:

[sjm]

imported post

ajm wrote:

hi,

my stag has issues with the ignition coil breaking down when it's getting hot (eg after 40 miles.) it was normally boltedbetween the vee,in this position,and with a sharp throttle opening it loses the spark as the engine falters,this was proven with the aid of a inductive strobe light.with a steady thottle opening it's ok.the problem only occurs when the coil is hot.

so I temporarily repositioned the coil on the bulkhead and went for a drive andthere is a vast improvement.has any body else had this problem? I have bought 2 new coils with the same result.

I am using piranha electronic ignition what is the correct coil to use for this?

i have unipart plugs fitted,could this cause a problem?

shouldI bolt the coil to the bulkhead permanently?

any suggestions?

cheers

allan.

Hi,

I had a similar problem and it turned out to be the piranha control box, was 27 years old thou.

Steve

[flying farmer]

imported post

V8 engines are very hard on their ignition coils as they need twice as many sparks as a 4 cylinder. I have been running both Triumph and Rover V8s since 1984 and have found the standard coils never last much more than 2 years. Keeping the coil cool and free from vibration by mounting it to the bulkhead can only help. I always use uprated coils as on my modified engine the spark blows out at 4500 revs on full throttle - not a lot of use with another 2000 revs to go!:X

[staggering]

imported post

Allan,

5 yrs ago, although I'm RV8, I had misfires etc and couldn't trace the problem. Had an MOT and failed on emissions, which it never had done previously. The Tester said"bet the coils breaking down". Got home and found the PO had located the coil near the ex manifolds :shock::shock:. Reocated a new coil to the bulkhead - ran like a "new" car and passed the retest with an emission value "better than some more modern machines"(Tester) - worked fpr me, just remember to run cables away from moving parts and use grommets to stop chaffing etc.

[ajm]

imported post

hi again,

I have since checked voltages on the coil,

ignition "on" with engine stopped. 6 volts on the coil

engine "running"10 volts on the coil (2,000 rpm),would anybody know if this wouldhave a dentrimental effect onthe coil after a few hours running??

cheers

allan.

[GDPR]

imported post

That'll be fine Alan - the 6v is showing the closed circuit value for the coil voltage with the coil switched on (the negative shunted to earth through either the points or electronic ignition system) the 10v when running is the average voltage returned between the 6v shunted and the 14v that would show when the circuit is broken to fire the coil (alternator charging so that's why 14v and not 12v)

Russ:dude: