Lucas AB14 ignition amplifier

[marshalla]

Right - I've just about had enough of the festering pile of ordure that is the Lucas ignition amplifier on my Excel (Lotus, not Hyundai). Since May last year, 3 of them have gone "pop" in sudden and spectacularly embarrassing fashion (passenger onboard every time).

Fortunately, I had a working spare onboard yesterday and changed it over in a few minutes in the pouring rain, but the question is - why are they failing ? The electrical system is completely standard and there have been no modifications to engine or ignition system. The only things I have changed are the stereo (to get something with USB and Bluetooth) and otterswitch for the rad. fans. Volts seems pretty stable and no other electrical bits are playing up, as far as I can see.

So - anyone have any thoughts ? What could be the cause of the sudden failures ? Does it do the same on other cars that use the same module (Jaguar, MG & TVR owners - I'm looking to you in particular) ?

Am I just unlucky, or is it proof that the car likes to have at least one niggling little fault and the trick is to keep fixing them until I find one I can live with ?

[shoehorn]

I don`t know if the Chinese have bought Lucas or whether Lucas are buying from the chines but the quality is poor now across their entire range and has been for some years now.
And they don`t seem to care!

Some of their products don`t even have the same functions as the item its supposed to replicate(citroen coil packs) and most of the Fords that suffer from coil driver failure I have seen have been fitted with Lucas coil packs.
Also are you using heat sink compound to mate the module to the distributor?

[marshalla]

shoehorn said:

I don`t know if the Chinese have bought Lucas or whether Lucas are buying from the chines but the quality is poor now across their entire range and has been for some years now.
And they don`t seem to care!

Some of their products don`t even have the same functions as the item its supposed to replicate(citroen coil packs) and most of the Fords that suffer from coil driver failure I have seen have been fitted with Lucas coil packs.
Also are you using heat sink compound to mate the module to the distributor?

The AB14 is a completely separate box that is attached to the hall-effect sensor in the distributor and the coil using good old fashioned copper wires. All of mine have been originals, refurbed with GM parts.

[Astacus]

Lucas was sold off years ago, I cant remember the name of the new owners now, but it really is nothing more than a trade mark these days

[jith]

You need to carry out a thorough, sustained output check on your alternator. Sounds like you have occasional spiking that is frying the ignition units.

J

[Incorrigible]

Jith, has a point, but IMHO junk the lot and buy a 123 dizzy

[marshalla]

Damnit! Another one gone pop - overnight, when the car wasn't even in use !

[nta16]

shoehorn said:

but the quality is poor now across their entire range and has been for some years now.

not so across the entire range - some parts got so bad that even the almost to a man tight fisted classic car owners that never uses their classics anyway decided they'd have to consider paying more than pence for items if they wanted them to work for the annual MoT and sunny Sunday local show

[nta16]

marshalla said:

Damnit! Another one gone pop - overnight, when the car wasn't even in use !

at this rate could it be something to do with the car or installation rather than the unit?

[arguti]

marshalla said:

So - anyone have any thoughts ? What could be the cause of the sudden failures ? Does it do the same on other cars that use the same module (Jaguar, MG & TVR owners - I'm looking to you in particular) ?

You need this -

http://www3.telus.net/bc_triumph_registry/smoke.ht...

[marshalla]

arguti said:

You need this -

http://www3.telus.net/bc_triumph_registry/smoke.ht...

I have some NOS high-compression smoke, but can't track down a left-handed whitworth syringe for the Lotus approved fitting procedure.

[V8 Fettler]

marshalla said:

Right - I've just about had enough of the festering pile of ordure that is the Lucas ignition amplifier on my Excel (Lotus, not Hyundai). Since May last year, 3 of them have gone "pop" in sudden and spectacularly embarrassing fashion (passenger onboard every time).

Fortunately, I had a working spare onboard yesterday and changed it over in a few minutes in the pouring rain, but the question is - why are they failing ? The electrical system is completely standard and there have been no modifications to engine or ignition system. The only things I have changed are the stereo (to get something with USB and Bluetooth) and otterswitch for the rad. fans. Volts seems pretty stable and no other electrical bits are playing up, as far as I can see.

So - anyone have any thoughts ? What could be the cause of the sudden failures ? Does it do the same on other cars that use the same module (Jaguar, MG & TVR owners - I'm looking to you in particular) ?

Am I just unlucky, or is it proof that the car likes to have at least one niggling little fault and the trick is to keep fixing them until I find one I can live with ?

It's generally a heat sink issue (see comments by others re: heat sink paste), Intermotor amps are supposed to be poor, although my Intermotor amp has worked OK for a couple of years. Has your underbonnet temp increased recently (otter switch replacement)?

Poor earths is another possibility.

[marshalla]

Went out to run some tests and swap a few bits over, while the office machine got on with recovering a poorly Mac HD. Damn thing started first time! I wonder if damp is getting in when the headlamp pods are up ? (it's mounted on the wing with one cable hole facing the front of the car - nicely aligned to catch any water that might sneak in under the front of the bonnet.)

[V8 Fettler]

Intermittent is typical ignition amp, but also typical of other faults. 12v at the coil but no HT spark?