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Long crank time '99 maybe not check valve?

jkmhb

NAXJA Forum User
My '99 is cranking a long time (15 sec.) before starting, only sometimes. When it does start, it idles really slow for a few more seconds before running normal.

I don't think it's the check valve because when I shut it off and try to restart it does it again right away. I would think if it was the check valve, it would take a while for the pressure to bleed off before the problem returns.

If I give it partial throttle when cranking it does start more quickly.

Sometimes it will start fine for several days before the problem returns.

Any ideas? Thanks!:confused::
 
OK - I checked the fuel rail pressure:

After sitting 8 hours - 0 PSI
After turning key to ON position without cranking - 40 PSI
After starting at idle - 45 PSI
At 3000 RPM - 45 PSI

It did not have the cranking problem when I checked the pressure above. It has the cranking problem only when warmed up.

I also cleaned the IAC valve and the throttle body - the problem still happens.
 
Since you have fuel pressure the problem is probably not the check valve or a leaky injector.

For 1997-2001 (and maybe 1996) OBD-II when (1) you let the battery rundown by leaving the lights or radio on, (2) disconnect the battery for an extended period of time, (3) or when the battery goes bad and needs replacing, the engine computer (ECU or PCM) re-boots and the idle settings are deleted. Your symptoms are; difficulties starting the engine without depressing the gas pedal, and the engine will have low idle and will probably stall unless you keep your foot on the gas pedal. The ECU will relearn the idle settings after a short period of time and the engine will start and idle normally. If the symptoms reoccur, you need to have your battery load tested. Even with low voltage, the engine will start but the ECU can re-boot multiple times and a new battery will be required.

Loose, corroded, or damaged battery cables or ground wires may also cause or contribute to the problem. Begin with basic trouble shooting 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 and replace as needed. Do the same for the grounding wires from the battery and engine to the Cherokee's frame/body. Jeeps do not tolerate low voltage or poor grounds and the ECM/ECU will behave oddly until you remedy this.

Have the battery load tested at a repair shop or auto parts store.

Cleaning the IAC and using fuel injector cleaner should be part of your routine preventative maintenance also.
 
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