I have a 1989 Corsica with 217 000 km on it, 2.0 l engine. Recently the engine started to surge when I would start it in the morning. When in gear, some mornings I have a hard time getting to the corner of the street. It stops, I start go again, stops, go again… When I can get to 50 to 60 km/h, it will not stop, but sometimes it hesitates and jerks real bad. I give it more or less gas and it’s OK. After driving for a while problem disappears, When coming back home every night, I never have the problem. No code from computer. I changed ignition module, no difference. I changed the fuel filter, no difference. I checked all vacuum hoses, they were OK. Pressure on gas line is 11 lb, book says 9 to 12. I replaced the oxygen sensor, no diff. I tried a computer from scarp yard and a MAP sensor from scrap yard, no diff. But mine back on. I unplugged the EGR valve and plugged the hose. Better idle, would not stop when driving but still jerks and surge at idle. I don’t know what to do next. Coolant sensor maybe? Something else?