Having recently re-kindled my interest in my 1995 SPi Cooper I thought I'd check it over with a view to using it more, after sitting for a couple of months I noticed that the car would lose power and stall everytime I pulled up to a junction and pressed the clutch-something it never used to do. In fact I noticed that this only happened when the engine had reached operating temperture and I could get it to stall when testing it at stand-still.
So having replaced the vacuum hoses (all except the yellow hose) and blowing through the fuel trap I tried it again and it didn't stall but was running really lumpy, having tried my spark plug testers it seemed that all four cylinders were getting a spark so I took it out on road test where I noticed that it was running really rough-again very lumpy and a complete lack of power.
When I returned home I removed the spark plugs, all were covered in a black soot indicating it was running rich, fortunately I had a new set of plugs (the correct flavour) and a new dizzy cap and rotor arm to replace the grotty old cap, all fitted and it fired up ok with none of the previous lumpyness and a road test showed the power was back to normal. I also removed the ECU and placed it against a hot water pipe to our domestic boiler but I couldn't for the life of me get any cotton wool buds into the MAP sensor port so I left it anyway but nothing came out. The temperature guage sits somewhere between the little white dot and the halfway mark so that would indicate that the coolant temp sensoe is ok wouldn't it?
My main problem now is that when I was testing it by 'blipping' the throttle it would rev and rev then I'd get a back-fire in the inlet manifold, do you think that the car might be running too rich as per the sooty spark plugs? or could it something else like a timing issue? am I right in saying a back-fire in the inlet only occurs because the valves aren't opening/closing at the right time creating a point where unburnt fuel in the inlet is ignited when the inlet valve is open slightly when it shouln't be? or does 'blipping' the throttle generally cause the odd back-fire?
Thanks for any forthcoming help.
Edited by dickster, 12 July 2009 - 05:39 PM.
