So the MAP sensor was bad but didn't completely fix the problem. got the RPM's to raise again to keep it idling right, and the new starting issue. i had another suggestion to check the o ring in the IAC, remove the o2 sensor to see if i may have done something else to the CAT i didn't notice, like maybe melting something inside to cause a blocking problem. so i'll be checking those soon as i can get my hands on the tools to do it. tonight or tomorrow. if y'all have any other suggestions they're greatly appreciated
ok so i replaced the tps sensor and checked the cat and no difference. just barely a stumble out of gear and as soon as i put it in gear the rpm's drop from normal and it acts like it wants to die. checked the fuel pressure again and still running 33 psi. the injectors are all firing and leak checked them again, all fine. i am completely outta ideas. any more suggestions?
did you disconnect the battery when you changed sensors? need to let PCM relearn its fuel strategy
a stopped up cat will cause low manifold vacuum. most of the I6s run 15-18 in/hg at idle
another thought....this started when you changed the water pump and now you get an injector code. suspect damage to wiring harness on front of engine. a very small breech of the wiring insulation could be touching metal.
only threw the injector codes when i disconnected them to check them out. after a few cycles of me checking things it stopped and only throws codes 12, 55. yes the bat was disconnected when sensors were changed. yes checked everything before replacing the sensors, got info from the dirty dozen jeep forum
after it goes into closed loop when it warms up, in gear, it wants to die and/or backfire. no power either. sputters and stumbles through a stoplight or stop sign. once i can get the rpms up near 1000 or above in gear it will get going but still hear that same intermittent stumble, same as i hear in P or N
the coil is mount on passenger side of block under alternator. it has a connector on it that is troublesome at times because the sockets get spread as mentioned in the.... hey i though you said you did the 12 things
my advise is to do a once over of your ignition system. pull the coil wire and look inside the boots for burning. same for plug wires. pull plugs and check for cracked insulators and proper gap. Pull cap and look for signed of arcing, crud, oil.
Zeejay gave you good advice. I'll only add this :
The coil has a ground below it on the engine block. The PCM also grounds there, by the way. Remove that nut and the wire terminals. Then crawl under and take a wire brush to the grounding point and clean up the terminal ends. After scraping the crud away, spray it with electrical contact cleaner. Then remove the coil and inspect it for hair line cracks on the engine side. Pay attention to the wiring connector too, as Zeejay mentioned. It's a known problem area.
I've also found that the TPS and IAC wiring harness area can be a problem. Wiggle the wires while it's idling to see if the RPMs change, like mine did.