ericfx1984

Will a low battery make a 1996 (OBD2) 4.0ho XJ run weird?

The reason I ask is today the battery was dead. I jumped the Jeep and it would not idle so I had to hold the throttle

I drove about 2 or 3 miles away and then I got back out and restarted the Jeep, it was fine, got about a 1/4 mile down the road and the Jeep started fluttering, 250rpm to 1250 rpm and finally died

when I came back outside (10 or 15 mins later) the Jeep fired right up and ran fine

When I got to my next destination I let the Jeep idle while I was inside (kept it in my view, lol)

wile I was inside I noticed every now and then it seems like the Jeep would 'skip', and after a few minutes it almost died and then it 'growled' Again it revved and ran perfectly fine after that

96WhiteCherokee

Wow, I had the same problem a few weeks ago. I still have not figured out whats going on. My wife killed the battery leaving the headlights on and after jumping it, it would not idle at first. Then ran OK for an afternoon, then later, would not start unless you held it to the floor.

Replaced the battery (10 VOLTS) and the alternator for good measure. Now it starts and runs but the transmission is messing up (electronic).

All because the battery went dead.......

Lowrange2

Yes, a junk battery can make them do all kinds of crazy things.

Put a volt meter on the battery while it's running and the same with it not running and let us know what it says.

rrich

You may have loaded a glitch in the memory. Clear the memory by disconnecting the battery for at least 8 hours. Jump startibg it often makes a spark - the PCM thinks it's a command and stores it in memory. Please let us know if it works.

5-90

Yes. The lower the battery is, the more it will soak up alternator output.

Electronically-controlled engines require a certain amount of current to drive all of the sensors, the ignition, the fuel injection, &c. - if that current isn't available, it will make things get stupid.

Also, low voltage/current to the ECU will cause the RAM to get flaky, and it won't read the tables in the PROM properly.

I've posted a writeup on how to check primary electrical for this sort of reason - find it and go through it. Ten minutes with a DMM will tell you more than you'll find out from the "tests" at AutoZone (which aren't very good - I used to service that equipment. The Bear ARBST is the only tester they have that's actually worth a damn...)