Discussion
I was out in the wife's Paul Smith mpi this morning when it suddenly went onto two cylinders (or that 's what it felt like) and the tacho needle dropped to zero. I managed to coax it home. A strong smell of burning was traced to the catalytic converter in the exhaust which was glowing red hot (unburnt fuel?) Is this likely to be an ignition module problem or what? It's booked into a garage on Wednesday to hopefully be sorted. Thank god my other minis have traditional ignitions and carburettors!
Hi, just joined PH, first time to post here. Happy New Year to all.
I'm guessing it's (half of) the ignition coil. The MPis have a wasted spark system that fires 2 of the 4 cylinders at the same time. These 2 cyls. share the same coil, so if the coil's gone bad the 2 cylinders would not fire, fuel will go straight into the exhaust and probably light in the hot cat, causing it to go red hot.
I've been reading quite a few posts from here which has been enlightening.
I'm guessing it's (half of) the ignition coil. The MPis have a wasted spark system that fires 2 of the 4 cylinders at the same time. These 2 cyls. share the same coil, so if the coil's gone bad the 2 cylinders would not fire, fuel will go straight into the exhaust and probably light in the hot cat, causing it to go red hot.
I've been reading quite a few posts from here which has been enlightening.
cyan said:
Hi, just joined PH, first time to post here. Happy New Year to all.
I'm guessing it's (half of) the ignition coil. The MPis have a wasted spark system that fires 2 of the 4 cylinders at the same time. These 2 cyls. share the same coil, so if the coil's gone bad the 2 cylinders would not fire, fuel will go straight into the exhaust and probably light in the hot cat, causing it to go red hot.
I've been reading quite a few posts from here which has been enlightening.
I have replaced the ignition module and everything was fine for about 15 minutes then it briefly went onto two cylinders again but then "chimed back in" and has been OK since. Could there be something else causing the same symptoms as a dodgy ignition module? This is the wife's car so I want it 100% reliable, or as reliable as a mini can be!!
cyan said:
I might be wrong but I wasn't aware of a separate ignition module. I thought on the MPis the coil is directly connected to the ECU?
What I am calling the"ignition module" is the black "box" from which the spark plug leads come. Is this what you are calling the coil? If it is where is the ignition module, if a separate one exists? I can strip an "old" mini down to its constituent nuts and bolts but the electronics of an mpi are a bit of a mystery to me (I must buy an up to date Haynes!).
That black box where the HT leads are connected to is the coil.
www.minispares.com/Product.aspx?pid=38290
My Haynes manual only covers the Spis, but looking at my Rover parts list for Minis after 1990 I couldn't find a separate ignition module as such, it's all in the ECU. I think what happens is the crank sensor sends signal to the ECU, which works out the ignition timing and signals the coil to fire the cylinders.
www.minispares.com/Product.aspx?pid=38290
My Haynes manual only covers the Spis, but looking at my Rover parts list for Minis after 1990 I couldn't find a separate ignition module as such, it's all in the ECU. I think what happens is the crank sensor sends signal to the ECU, which works out the ignition timing and signals the coil to fire the cylinders.
cyan said:
That black box where the HT leads are connected to is the coil.
www.minispares.com/Product.aspx?pid=38290
My Haynes manual only covers the Spis, but looking at my Rover parts list for Minis after 1990 I couldn't find a separate ignition module as such, it's all in the ECU. I think what happens is the crank sensor sends signal to the ECU, which works out the ignition timing and signals the coil to fire the cylinders.
Thanks for the explanation.
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