Morning all

After changing the head gasket, timing belt and water pump I've nearly got the car sorted and driveable... The remaining issue is once the car starts to warm up the idle bounces from 1k - 0 Rpm repeatedly.... I've searched for a leak to no avail and when I unplug the MAF it improves short term only to start lurching again. Spark plugs and leads were changed when everything else was done.. I've been reading and reading and I think the coolant temp sensor may be contributing to this. I changed the temp sensor to a 3 pin and wired in the gauge wire to it in addition to the ecu wires. The temp gauge appears to work and slowly moves up to half way but I cant help thinking that possibly the ecu isn't enjoying the 3 pin approach and not giving the right coolant temp. Anyone got any info on the 3 pins being used on a my98 or earlier? or any other suggestions are much appreciated.

changer the maf sensor

Fit the correct temp sensor