My fuel injected 92 Ranger (200,000 miles) always started and ran well...until a month ago. I need to apply gas to start it these days and it will not idle until it's warmed up. Fuel pressure regulator is good, any ideas? Thanks!
I agree that it is most likely the idle air control valve. The best way to be sure is to "pull the codes". I recently had a similar problem with my 87 2.3. When I did the KOEO test it indicated a code 63. Emissions and diagnostics manual indicated a test to run if you get a code 63. Do test by shorting the TP and Ref Voltage connections at the TPS connector on engine side. Then run KOEO test again and see if you get a code 53. I did get a code 53. Manual indicated that positive on code 53 means bad TPS. Replace. I got one at Autozone ($42.00) and installed it. I then got a code 11 (No problems indicated) and the car cranks easy and runs great. No more idle problems cold or hot. Amazing!!
Clean your IAC and if that doesn't help, take it to Autozone for a free check of the engine codes.