I've been chasing a gremlin in my 2001 Jeep Cherokee for almost 6 months now. symptoms are as follows:
-on a cold start it'll run like hammered ***. CEL flashes, multiple cylinder misfire (always cyl. 3 and others are randomly dropped) up to 3 at one time.
-if you let it get to running temp (it can't just idle I've tried; you have to actually drive it) turn it off for 2 minutes and turn it back on she runs like a completely different vehicle. CEL is still on but not flashing, idles a little rough but not bad enough for anyone but myself to notice.
-as long as the engine doesn't cool completely she'll run fine for the rest of the day.
list of things i've already tried to avail:
-new plugs, all NGK
-new injectors (they were old anyway. i figured why not?)
-new coil pack
-new crankshaft position sensor
- i have a heat shield on cyl. 3/manifold/fuel rail.
compression tests check out fine. noid test on injector wires are fine. I really don't want to sell but i might have to if i can't figure this out.
just put in a remaned long block in june. does anyone have any ideas?