1995 YJ 2.5 has a rough and low idle

[dt114`]

1995 yj 2.5 low idle, and the local mechanics cant figure it out. when i bought it 4 months ago most of the sensors were originals. so i replaced them all, map, 02, iac, tps, air charge sensor, new plugs, wires, cap rotor and coil. when i first put the tps in it actually idled normal for about 10 mins then died back down to 300 rpm. and at temperature that is where it idles runs rough and has a miss. at speed seems to run fine. fuel rail pressure is at 31psi. I am stumped and wishing i had never bought it at this point. Any subjections??? any at all??? anyone?? other than sell it, to deep into it now for that.

 

[Gilaguy23]

Interesting. My 91 2.5 idles a tad low it seemed so i replaced the IAC and the TPS. I have 3 of each including new Mopar units. Any of the 3 new ones make for a 1100 rpm idle. Unfortunately I trashed the OE one in the process of getting it off the TB or Id reinstall it. At this point I really dont care anymore after a couple years of it being this way. I will ad that some do have an adjustable pintle. It screws in and out. Im thinking the controlled throw of the pintle is just so much and if its screwed all the way out slowing down the idle in your case, the driver simply cant pull it in far enough to get the computers wanted 800 rpm idle. Don't know, but ask yourself if the pintle is adjustable, and for the jeep there is a recommended height before installing it, experimenting might help. My $.02 on computers and their associated BS parts like failing fuel pumps that leave you stranded in BFE, is they belong a desk, not my vehicle. I digress.......Good luck with it. Id Also check the grounds and voltage to the IAC.

 

[dt114`]

I am use to working on older cars, grew up in the early 80s working for a garage on weekends and summers. but this is absolutely 1000% aggrovation. when i bought this one it had some simple neglect issues. all sensors were original to the jeep, all of them. it actually died on my doing 65 on the hwy, no spark. turned over fine would never hit. no check engine light, but i checked codes anyway and i did get a code 11*: No crank reference signal detected during cranking. Timing belt skipped one or more teeth; or intermittent loss of either camshaft position sensor or crankshaft position sensor. sense i knew they were both original sensors started with crank ps, not the problem. replaced the distributor switchplate next or camshaft ps as they called it, and it imediately cranked.
but this low rough idle is a bitch. i cant find any vacuum leaks replaced all sensors new because they were old. same outcome. changed plugs, wires, cap, rotor, and coil pack. idles at 300rpm and rough.