A strange start

Okay , get ready for a doozy. I'm sure someone will know much more than I do and make this seem simple.

I'm looking for answers to a problem that arose last night.

So my 1999 4.0 has always started a little slow, three-four cranks for her to turn over, but this escalated quite a bit.

Yesterday I piggybacked (using 16 gauge wire) the drivers side running light wire to the passenger side running light because the latter wire wasn't receiving any power. I drove it around the block to the front of my house with no issues, where it sat for 4 hours before I drove it to my buddy's house, at about 845 pm. Due to it being night, headlights were on and thus both taillights.

At my friends house, we went to drive after about an hour and my jeep would not start. Lights worked, dash lights worked, battery indicator seemed normal, but 3 cranks and no turnover before having to turn key to initiate another start. No luck.
Naturally, I got a jumpstart from his Montero and we took off.

After a good hour and a half of driving we parked, took the positive terminal off, and left to hike hoping it would start as normal once we re-attached the battery.

It did not. I cleaned dielectric paste from the positive, unwired my piggyback, and we managed to get it started after a real cliffhanger of cranking. Drove for about 15 minutes, and disconnected pos. After being left an hour or so, she started up alright, but a bit slower than normal.

This leads me to the curious part. After driving everyone home, I left the jeep parked out front of my house positive connected, and this morning it started right up in the normal sluggish fashion.

I will be driving to Alaska from MN this January for college so I'd love to figure out what's wrong here. Any advice to get my cherokees starting fixed before I'm in -30 temps?

Sluggish meaning cranks slow, or sluggish that it takes longer before it fires?

Sounds like it cranks a little slow, but mainly just takes a little bit to turn over.

Seems like some preventative maintenance should be on your to-do list. How old is the battery ? Have you has it Load Tested ? A slow start on a good battery is typical of a failed fuel system check valve.

For Alaska I would want a fresh battery with lots of CCA.

Perform routine maintenance of the start and charge systems. Remove, clean, and firmly reconnect all the wires and cables to the battery, starter, and alternator. Look for corroded or damaged cables or connectors and replace as needed. Copper wires should be copper color, not black or green. Battery terminals and battery wire connectors should bright silver, not dull gray and corroded. Do the same for the grounding wires from the starter to engine block, the ground wires at the coil, and the ground wires from the battery and engine to the Jeep's frame/body. You must remove, wire brush, and clean until shiny the cable/wire ends and whatever they bolt onto.

Jeeps do not tolerate low voltage, bad wire connections, or poor grounds.


Place your DVOM (Digital Volt Ohm Multi-Meter) on the 20 volt scale. First check battery voltage by placing your multi-meter's positive lead on the battery's positive post ( the actual post, not the clamp ) and the negative lead on the negative post. You need a minimum of 12 volts to continue testing. Next, leave your meter connected and take a reading while the engine is cranking. Record this voltage reading. Now connect your positive lead to the battery terminal stud on the starter and the negative lead to the starter housing. Again, crank the engine and record the voltage reading. If the voltage reading at the starter is not within 1 volt of battery voltage then you have excessive voltage drop in the starter circuit.

Typical voltage drop maximums:
• starter circuit (including starter solenoid) = 0.60 volt
• battery post to battery terminal end = zero volts
• battery main cable (measured end to end) 0.20 volt
• starter solenoid = 0.20 volt
• battery negative post to alternator metal frame = 0.20 volt
• negative main cable to engine block = 0.20 volt
• negative battery post to starter metal frame = 0.30
• battery positive post to alternator b+stud = 0.5 volt with maximum charging load applied (all accessories turned on)

Thanks for the instructions! Ill make sure to check connections, grounds, and battery function. The strange part is the battery is a less than 2 month old MT34 with 700cca, replaced because the old battery wouldn't start the car.

I am wonderig how much of an effect my rigged up tail light had, as the jeep seems to be starting as normal now.