start-up troubles

[paul10]

I am having occasional problems starting my '97 JGC Limited. It only occurs on the first startup of the day (then starts up fine the rest of the day), and only happens about once a week. What happens is it revs up, but, instead of holding it's RPM's, just revs and drops back down -- cutting out. I have been holding the accelerator down at 1,000 rpm's for approx. 30 sec.'s and then slowly letting up. After this little trick, it will hold its idle, and it will run just fine too.

Does anybody know what could be causing this problem? There are no error codes coming up, and no check engine light.

[fredjacksonsan]

How is the state of tune? Have the plugs/cap/rotor/wires been replaced reasonably recently? How about the air filter? If all these things need to be replaced, it could cause something like you're experiencing.

[xj31]

hows the battery?I have seen weak batteries cause this.It seems like the pcm loses its memory and needs to relearn.

[paul10]

a tune-up was my first thought. i just bought this thing less than a year ago, so i do not know when it's last tune-up was, but that is definitely a possibility. i was just hoping to get some help before i took it into the shop again. did that two weeks ago, and they just fixed the first thing they saw -- a bad 02 sensor...obviously did no good for my start up.

also, different question: what are the symptoms for a jeep with a crankshaft position sensor going bad? this was something else i tabbed as a possible problem. the ce light does not come on.

[paul10]

battery reads at full power while i'm driving. it does have some buildup around one of the terminals. i'll clean that up and see what happens.