The amp is new (1 year, 2000 km) and bought as a complete AB14 box from Manners or Barrett.
The issue is at super low engine performance, ie below 50 MPH, where I barely have to touch the throttle to make the car move. Opening the throttle will cool the inlet and thereby amp, so flooring it helps after a little time.It will probably also help to pull a caravan...

Leo

 

Hell of a good diagnosis Leo, congratulations. At Grant's suggestion, I moved mine out front, pic attached below. I just made extensions from normal good quality wire, including the normally shielded wire, and absolutely 100% no bother. The new bits of loom are wrapped in a cover and that is it. I actually cut the all the wires (leaving a tail) including the ones that come up from the dizzy to the plug at the side of the amp, and let in longer pieces so that the original plugs could be used to make the connections into the amp. I used those heat-shrink and solder melted things. Absolutely 100% perfect since. Go for it!
I made studs as per photo (nut each side of the panel) added another nut for extra airflow space, placed the amp, nut and washer on top. Two important things:
You MUST run a good earth just like on the manifold. I ran it to the earth-point under the LHS radiator-panel fixing bolt.
Second, as it is Europe and not Oz, VERY carefully waterproof the amp. RTV round ALL the seams and holes where wires, plugs etc etc enter the box.

 

Thanks Greg.

Great to to see how you have placed yours. Before you posted, I checked if there is room for it on the panel over the radiator like on the Marelli cars, but it would be very tight. And warmer. And still not dry. Your position is better.

I just checked, I have all connectors except from the bullet in stock in both make and female, so I will see if I can find the bullet and then leave the original connectors in place and make a connecting cable with connectors in both ends. Unless I change my mind and go for soldering in an extension. It is my car, after all...

I have edited my ice cube post, added a picture of the ‘setup’

 

I'm making a new enclosure for mine, sandwiched between two aluminum heatsinks, new connector and mounting out front. Belt, suspenders, and duct tape!

 

The heatsinks are very important, as I believe the module can draw about 7 amps.

 

NOT XJS, but Peter in Melbourne, maaany years ago had the same with his S3 V12.

NO room out the front, so he mounted it under the passengers seat, on a heatsink thingy, with a PC fan.

Still works as far as I know, A/C comfort in Summer, and Winter, who cares.

 

Extension cable fabricated, amp sealed and moved, car driven 27 km this morning at 25C. Zero issues doing 40-45 km/h after getting off the motorway, and that is normally this biggest challenge. We will see 30C this afternoon, look forward to driving home !

My temp needle was sitting lower than normal. It is normally in the N, but stayed below today. I do not understand if overheating amp causes more heat in the engine ?? That said, my temp needle position is not really reliable...

 

Well done Leo.

Not scientific at all, God forbid, but an over heating amp MAY retard the dwell a tad, and that will run the beast hotter.

 

Sounds very good, low engine temperature is what everybody wants. Slightly scientific though, if you ask me, but I know late ignition is (or can be) used to warm up the engine faster

Leo

 

So we replaced the coil and the ignition module I side the amp. It starts and runs just fine. I am yet concerned that the amp box itself heats up very quickly and its not from engine heat cos below the amp housing it's still ice cold after a minute or two but the amp box is hot. So I'm saying the heat is not transferred from the motor. The module itself is exerting the heat. How is the earth wire run... From where to where cos I want to check that as a possible cause? Can a bad earth cause the heat build up?

 

That is normal. the amp produces more heat at low engine revs than at high revs.

 

Thanks Greg! I bought two spare ones so I'm just going to drive it like that then. I'm still curious about the earth wire and if that can cause heat build up?

 

I take it that you have connected the earth wire?

 

Bad or iffy earths will cause all sorts of resistance, and that is heat in itself.

Most Amp heat, outside accepted, I have found to be:
OLD HT leads, or New that are too high in resistance.
Spark plugs gapped too wide, and then of course, OLD spark plugs, usually 1A and 1B.

Cap and rotor age and quality creeps in down that list a tad.