97 XJ 4.0 Cranks, No Start When Cold

Started happening yesterday, when cold didnt want to start. took a solid 5 minutes of cranking before she started up. once running ran perfectly fine, once warm could be shut off and restarted no issue. now she wont start at all, check fuel pressure with a gauge and is within spec, checked and has spark also. was throwing a p0320 code randomly, replace connector after finding chaffed wires and has a MOPAR cps that is no more than 4 months old. noticed when cranking if you hit the gas pedal there is a backfire (assume) out of the throttle body. jeep cranks easily and sounds like it wants to start but nothing. any help or leads appreciated.

Check cps wire " make sure it is not laying on something hot and melted the wire causing a short"

Sounds like it may be flooding. There is timer relay circuit as I recall that allows the PCM to reset the IAC controller in the throttle body. It or the IAC or dirt in the IAC-throttle body may be an issue. You can unflood it by cranking with the gas pedal floored. That tells the PCM to cut off the injectors while cranking

It is very likely flooded after 5 minutes of cranking, but that is not the root cause of the no-start.


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)

Test the output at the alternator with your volts/ohms multi-meter. You should be measuring 13.8-14.4 volts.

Load testing the alternator and battery is strongly recommended.