SPI ECU?

[wole0911]

Just wondering if anybody could shed some light on my sons old spi Mini Cooper 1993 model. ......
It seems to run ok for a while then all of sudden it starts running realy rich and becomes pretty undrivable until you park up clean the plugs which by this time are so sooted up they wont arc a spark, sometimes it will run ok for a day or so and then bang it starts doing it again !!
Its been up to Gearald Dale mini specialists and he has changed just about everything except the ECU and has suggested sending away it to be checked which im just about to do but was wondering what the vacum conection on the bottom is all about as this was filled with fuel?
Thanx...Mark

[Hrimfaxi]

Sounds like a vacuum leak...
Check all lines between the ECU > fuel trap > inlet manifold.

Even the slightest little nick can cause havoc, I had the same problem with my '95 SPI. Also check all joints.

If in doubt, just replace the lot! It's cheap enough.

[CarsOrBikes]

If the vacuum line is filled with anything, it needs cleaning out, empty the vac trap on the rear of the injector/manifold, remove the ecu and insert some thin string or cotton into the vac hole, and turn correct way up with that inserted and leave on a hot radiator for a couple of days to draw it out. Coolant temp sensors can cause overfuelling, and the ptc heater under the manifold can cause weird symptoms iirc.

[wole0911]

Ok thanx for your posts ive sent the ECU away to be checked and will get my local mechanic to check the points you have posted

[CarsOrBikes]

I had another thought, if it's a 93, it may have a throttle switch above the pedal, they would cause that when failed, and not fitted to the later ecu cars. Worth testing.

[wole0911]

Throttle switch above peddle ....will I find that or what it looks like in his Haynes manual?

[casbar]

Read this thread http://www.theminiforum.co.uk/forums/topic/49801-s...

This is explains the stepper motor, which works differently on my MPI, but its a right royal if its broken, mine was and had to source a new one. My symptoms were high raving, but it looks like it is different on the SPI, results in rich running etc