5 replies to this topic

[maxi23]

My SPi has managed to develop a slight miss.

I have read through several thousand threads so far and have figured it is something to do with vacuum pipes/ecu. Now, I am in need of some opinions as to whether I might be right.

When the car is started, it runs fine for about 30 seconds. I assume this has something to do with the ecu not kicking in and doings it's thing until engine reaches a certain temperature ?

Once it has idles for a short time, it starts to miss and appears/sounds as though it's running on 3 cylinders (or as if one cylinder has a really weak spark).

I can drive it, and all the power is there when the engine is under load, but as soon as I stop putting load on the engine the miss re-appears and the popping and cracking from the exhaust starts up also.

I have swapped my leads, they are all fine. I haven't replaced the coil.

Would I be correct in thinking it is more than likely a leak somewhere ? ie, dodgy hoses on the back of the manifold ?

[cbyrne]

defo sounds like the vac to the ecu i hade the same problem it was the vac line from the inlet to the map sensor the ends of the pipes were split

[maxi23]

I will be having a look at this tonight, hopefully a new hose will get me back on the road!

[Darkscamp]

hopefully it is a vacuum pipe but just bare in mind that i have seen this as a headgasket failure as well.

when not under load it can happily leak through a crack in the gasket between the cylinder bores causing it to technically sound like its on 3. then when placed under load its forced past the crack making it run perfectly again.

sorry if this doesnt make sense but i'm sure a guru will be along soon to explain a bit better.

[maxi23]

After some talking to the local mini/european garage I have some more things to investigate.

After taking the plugs out, number 1 was fairly white, number 2 was a little less white. Now his line of thought is that there is a possible air leak on the inlet manifold, that when load is applied (as explained above by another member) will dissapear.

Plan is to remove the whole manifold/injection assembly and work my way back from there.

This is one problem I haven't encountered before, so it's good to learn some new things.

[maxi23]

Problem solved.

A previous mechanic didn't bother to do up any of the exhaust & inlet manifold bolts tight enough. to give you an idea of how bad they were,
I was able to tighten them up with my fingers.