Engine Performance problem
1995 Other Plymouth Models 4 cyl Front Wheel Drive Manual 60,000 miles
Plymouth neon Sport 2.2 vin c.
Runs fine until hot. Cooling fan comes on, problem begins. Engine idle is high and erratic. No power, and loss of about 2 cyls. I have another vehicle of the same type that was running fine until a timing belt broke and bent all the valves ! I have swapped all engine control sensors, throttle body and pcm. Coolant temp is at 210 degrees.
I have disconnected all vac sources. Sprayed intake manifold area. Scan tested for codes and some sensor values with scanner. All our normal. Vac is running at about 18", but erratic. I have drilled 2 3/8" holes in exhaust pipe above converter to check backpressure. Replaced all ignition wires, plugs, fuel filter and checked fuel pressure at 50#. Egr is ok. Goes into closed loop and o2 sensors are working. What next? I am a auto mech. Retired 34 years ! I have no source for technical data.
Thanks in advance for any help on this problem. If you help I will donate with no problem.