Engine running lumpy on bottom end

[lkcio86]

Just bought a 1995 16v clio with a williams engine conversion (supposedly), its running really lumpy under load at low revs, misfires etc, until 2000rpm then its fine, i looked at the ecu code numbers and its the original 1.8 16v ecu, is this the problem, if so anyone have an ecu for a williams engine :roll:

[Coops]

check the front of the engine block for a metal plate, if it says F7R on there its a williams lump, if it says F7P its not. that'll clear up the possible confusion on the ECU

check plug wells for oil as possible for misfire