Problem: 1.8L 1995 Ford Escort with an idle that fluctuates between 850-1,200rpm and sometimes just dies when idling in neutral. No vacuum leak found. I don't believe it is the ECU, but possibly the throttle position sensor or the fuel pump that is going bad. No code shows up when a diagnostic is done, but I have heard that this is possible when there is a problem with the TPS. Your thoughts please. Thanks.