Baffled, breakdown and no idea of the cause.

[dixiebabes]

Disaster, rusty nail X Round the corner and the wedge decides to break down. Same thing that happened before which i thought was water ingress into the dizzy area. Started fine then decided to cut out on idle, fired back up after a struggle and seemed like it was only running on about 4 cylinders. Revved it up and after a bit seemed to clear. Got my nephew to follow me so i could give it a good blast up the dual carriageway. A few massive backfires and it cut out but this time it wont start back up and had to be towed home which resulted in shearing the radiator fixing off underneath, any ideas lads cause i have no idea maybe a blocked fuel filter or fuel pump on the way out??? It ran fine for the first few miles and then all this happened.

[adam quantrill]

Could be an exhaust lobe on the camshaft rounded off, this causes front-firing and similar symptoms, try turning over with rocker covers off and watch the rockers.

[dixiebabes]

Just done the usual checks Adam, I'm getting a yellowish spark from the coil lead when i arc it on to the rockers and crank it but no spark from the plugs so that seems to be the problem. Any advice on where to start looking now?

Dix.

[adam quantrill]

Rotor arm? Could be a pinhole causing breakdown/arcing to the central dizzy shaft.

Or else the centre stud on the inside of the dizzy cap, is that still there?

[dixiebabes]

Yeah carbon bush is still there and moving ok. The cap and rotor have been changed recently due to a crack and arcing in previous 1.

[SLB]

Could be the ignition amplifier on the side of the dizzy. Mine got wet due to a dripping swan neck cap and in the end I moved it next to the coil. Gave similar symptoms to what you had.

[KKson]

Agree, 9 times out of 10 seems to be the ignition amp these days. I've had three fail in 4 years. One died completely, one died whenever the car got hot and returned to life when things cooled down and one died randomly whenever it felt like it. Try sticking a very cold cloth on the amp for 10 minutes and then try starting it.

If you are loosing your spark when driving then the back fire will be unburnt fuel hitting the hot exhaust manifold on the way out.

[adam quantrill]

Ahh but if there's a spark at the king lead it's not the ignition amp (at that point in time anyway).

If you have changed the rotor arm recently then the new one might have failed. I had one fail after only a few thousand miles.

[KKson]

adam quantrill said:

Ahh but if there's a spark at the king lead it's not the ignition amp (at that point in time anyway).

If you have changed the rotor arm recently then the new one might have failed. I had one fail after only a few thousand miles.

I had a weak yellowish spark at the king lead but bugger all on the cylinder leads. The spark wasn't man enough to fire the engine. When I put a new amp in the spark was then big, fat, blue and could jump a good centimetre.

[SLB]

KKson said:

One died completely, one died whenever the car got hot and returned to life when things cooled down and one died randomly whenever it felt like it. .

Yes, same with mine, don't bother with the cheap ones which last a year or so, go with a genuine Lucas one which isn't much more. I think the kit I got off ebay was fifty something pounds which included a new amp and the bracket and cables to move it to the coil.

[dixiebabes]

Sounds like a new amp is the way forward. Anybody have a link to a new one, early v8 1983/84.

Dix

[dixiebabes]

Just had another look now back from the pub. If im honest i cant see anything on the dizzy what looks like an amp. Have a picture here but not sure how to post em?

[mark387mw]

I had similar symptoms of cutting out, not starting, smelling rich and half the cylinders not firing.
I cooked the starter motor in my attempts to start it.
Turned out to be the ECU. Dry joints etc. Got it resoldered and it then drove better than ever.

[Solitude]

Dix, I reckon your car (as mine does) may have a remote amp.
Mine is under the coil (silver rectangular thing with wires running to the dizzy)

Edited by Solitude on Tuesday 18th September 08:43

[Solitude]

Check all the (minor) wires on the coil lugs for connection too.

[Solitude]

Check the 'minor' wiring connections at the coil...... They are easy to work loose

[phillpot]

Solitude said:

Dix, I reckon your car (as mine does) may have a remote amp.
Mine is under the coil (silver rectangular thing with leads).

Like this?..................... clicky

[Solitude]

phillpot said:

Solitude said:

Dix, I reckon your car (as mine does) may have a remote amp.
Mine is under the coil (silver rectangular thing with leads).

Like this?..................... clicky

Almost !!
Guess they are the same thing but different models

[dixiebabes]

This must be the beasty with the coil bolted to it then eh lads? Just took it off.

[SLB]

This is the kit I bought for my 88 350i but I got mine from ebay and I can't see any on there right now. The actual amp on the side of the dizzy is the central black item in the photo with two holes.

https://www.autoelectricalspares.co.uk/lucas-42599...