10 replies to this topic

[ryomini]

Hello, hello, hello, to all you Spi and Mpi mini people

 

I have a jap spec '93 Spi mini that I am rebuilding in the saloon section 'Project W'

it has an orange relay box under the dash

stanley DV075-41360A

 

it has 2 plugs one is a 2 pin, the 2 pin has a white and red wire in a silver insulation cable

the PO has shorted these 2 wires.

 

Can someone tell me what that does and if I need to change it and do some tests.  Sorry but I am pretty miserable at understanding electrics but can usually fix things if given a little help

 

cheers and thanks for looking

 

[FlyingScot]

AFAIK Its the catalyst overhead alarm system which has a supply and would have been connected to a sensor in the catalytic convertor. It makes a noise when it detects high temp in the catalyser.
Personally I would remove it.

FS

[ryomini]

FS hey it's been a while thanks for your help once again

 

I think I'll leave it shorted out, as I guess the PO did such because it overrides the problem, if not yes, I can just unplug this pretty useless device,

one less thing to worry about for now ;)

[xrocketengineer]

Interesting. Apparently the Jap spec. Land Rovers also had them.......

 

https://www.landyzon...y.174635/page-3

[minimat]

I wonder why they fitted it,we dont have them in the uk.

[xrocketengineer]

Apparently a Japanese requirement according to this: http://www.jag-lover...08-Exhaust.html

 

"Back in the 1970's when I was working in Emission Control Dept. at Jaguar one of my responsibilities was complying with Japanese Heat Damage Tests. Amongst other things this meant having a catalyst overheat warning system (via a thermocouple in the cat) and the test procedure called for one spark plug to be disabled while idling to prove the system worked. The mixture from the dead cylinder would then be burnt in the catalyst which would obviously get a bit hot. On the old oxidising catalyst systems this was not unduly dramatic, but even so because the carb XJ6's had the cat well back under the car, if driven any distance in this condition, they could end up with the rear seat springs popping through the top of the seat!

"Now when we started using Lambda sensors on the 4.2 EFI engine the situation changed alarmingly. When a plug was disabled the Lambda sensor would detect the spare oxygen from the dead cylinder and the system would react as if the fuelling was too weak so swung to the rich limit in trying to correct it. The catalyst now would be getting a supply of air and extra fuel and would start to glow in no time at all, even at idle.

Edited by xrocketengineer, 17 March 2016 - 09:48 PM.

[spiguy]

I initially left mine wired up when I replaced the exhaust, but wired in a 100 Ohm resistor - the probe is a PT100 (Nominal 100 Ohms) temperature probe. 100 Ohms just makes the box think that it is always at a low temperature. 

 

I have since removed it when I was doing other things in the dash area, and also because I wanted to use the 12V feed for my oil pressure gauge bulb!  It was the exact same Stanley box as yours ryomini.

[ryomini]

Wow guys some interesting info here,

thanks for your experience and experteese

 

when I get to testing with a 12v battery I'll see what happens when it's unpluged - if no drama it will stay off - I mean fire is a hasard but it's overengineering imo.

 

I have a couple more pix to post as there are a couple of other little niggles that I need be sure of before putting juice through the system

[FlyingScot]

I initially left mine wired up when I replaced the exhaust, but wired in a 100 Ohm resistor - the probe is a PT100 (Nominal 100 Ohms) temperature probe. 100 Ohms just makes the box think that it is always at a low temperature. 
 
I have since removed it when I was doing other things in the dash area, and also because I wanted to use the 12V feed for my oil pressure gauge bulb!  It was the exact same Stanley box as yours ryomini.

Thought I had had this discussion with someone....a fellow MiniClan fuel injection nut

FS

[spiguy]

 

I initially left mine wired up when I replaced the exhaust, but wired in a 100 Ohm resistor - the probe is a PT100 (Nominal 100 Ohms) temperature probe. 100 Ohms just makes the box think that it is always at a low temperature. 
 
I have since removed it when I was doing other things in the dash area, and also because I wanted to use the 12V feed for my oil pressure gauge bulb!  It was the exact same Stanley box as yours ryomini.

Thought I had had this discussion with someone....a fellow MiniClan fuel injection nut

FS

 

Ha ha, there has to be a couple of us at least to offset all those carb nuts!  

[ryomini]

Yes there are not so many of us running the Spis, but I do find my daily runner to be fab