E30 Zone

*Edit - I suspect it is the crank position sensor now after reading the wiki. If you's still like a look at my problem see below:

1990 2.0i manual. Speedtouch 'wild' chip. Recently had exhaust repaired (2 new end bits welded on). All fluid levels in check.

Started this morning and when it gets above 2000 revs it splutters, coughs and then is like that all the way through the rev range. If you drive it it bunny hops violently. Got it nice and warm for 1/2 hour - no joy.

Has only had a small amount of petrol in tank for the last week.

Drove it 40 miles yesterday, no problems but had been sat in the cold for 48 hours before that - I say sat, I did go and start it up each day to run the engine for 10.

Have checked the little, visible fuel hoses on top of engine, seem tight/in place.

Spark plugs seem in place.

Was cleaning the cylinder head the other day, water somewhere?

Everything else seems to be normal, not overheating, not too cold. Fan is ticking normally. Electrics aren't cutting out or power dipping anywhere (lights/dash etc).

Cleaning the head might be the cause check the c191 connector under the inlet manifold and I know it sounds silly but is your afm connected. With out the AFM the car doesn't know you want to do and can't increase the rpm until after the fact when it sees it in the CPS reading therefore the fuel map and Ignition map always lag behind the desired. Also check that the fuel pump relay is 100%.

One other possible is that your tps is only giving you the idle map to play with

checked connections were ok and after that it worked fine. I will have to do some proper checks now so it doesn't happen again. Thanks abelai. Very informative, afm all good.