2000 Jeep Cherokee Intermittant Starting issue has escalate

Tiny
2000JGCLTD
  • MEMBER
  • 2000 JEEP CHEROKEE
  • V8
  • AWD
  • AUTOMATIC
  • 106,000 MILES
2000 Jeep Grand Cherokee Limited
4.7 L Power Tech
All Wheel Drive
It’s probably been a year since I talked to you about the intermittent starting issues I was having with my Jeep. I was convinced that the problem was the result of a fuel pump failure. After purchasing a new pump, my mechanic told me there was no reason to install it because my fuel pressure and pump were fine. When I brought it in last, they claim that no error codes were being produced by the computer. Shortly after I picked it up, the check engine light came on but it continued to run fine. Occasionally, the jeep’s symptoms would return (maybe 1 in every 50-75 starts) but after waiting a few minutes, the engine would fire right up so I paid little attention to it. A few months ago I noticed an ever so slight noise coming from the engine that I had not noticed before. The best I can describe it as is a faint chirp sound almost with a hint of the sound of slight vacuum pressure. The most interesting thing about this noise is that it continues for a second after the ignition is turned off. I first noticed the sound when I parked in the garage, turned the engine off and heard it when I jumped out of the truck. After noticing it, I cranked it back up and could hear the faint chirp, ping, suck noise.
I’ve been researching the symptoms and asking around a couple people have mentioned two sensor issues on Jeep Grand Cherokees that have been problematic: crankshaft position sensor and/or camshaft position sensor. I’ve located them on my engine but I can’t justify digging around and replacing them when I really don’t know for sure if either of them are causing the problem.
Does my rambling bring any ideas to your mind? Any advice you can share would be much appreciated. Btw: the jeep last started 2 weeks ago. I’ve made approximately 10 attempts to crank. It turns over but acts as though there is either no fire or no fuel… I’ve read that a bad crank sensor will disable the vehicle?
Anyway, let me know what you think. I’m guessing I should probably just take it to a jeep dealership at this point to see what the computer is saying now that it won’t start at all.
Do you
have the same problem?
Yes
No
Sunday, March 28th, 2010 AT 10:57 AM

3 Replies

Tiny
JDL
  • EXPERT
Hi, thanks for the donation. If it cranks good, but, won't start, have a helper crank it, while you visually check for spark at the plugs. If you have spark everywhere, use a gage and check fuel pressure. Some of the national brand autostores used to loan out a fuel pressure gage, if you don't have one.

I didn't look at specifics on your vehicle, even if you have COP ignition, you should still be able to visually check for spark at the plugs? For a start, try to find out if your missing spark or fuel.
Was this
answer
helpful?
Yes
No
Monday, March 29th, 2010 AT 12:40 PM
Tiny
2000JGCLTD
  • MEMBER
The fuel pressure is great but I don't know how to check for spark. The plugs look like a hassel to get to because it does in fact have COP ignition.
It is my belief that when the jeep will not start there is a sensor preventing the plugs from firing.
Thoughts?
Was this
answer
helpful?
Yes
No
Monday, March 29th, 2010 AT 2:32 PM
Tiny
JDL
  • EXPERT
Saying fuel pressure is good, won't work with me, I need the actual spec? If you can't do a little testing, I'm not sure how to help? Take the primary connector loose from the coil, check for voltage, engine cranking. You can do the same at the injector. Check applicable fuses for voltage circuits. If there was a sensor issue, I don't know why the computer would energize the fuel pump relay and not energize the asd relay, usually a sensor issue will not let either relay energize. If no primary voltage at coil and injector, that voltage comes from asd relay, that relay also supplies voltage to other systems. I'd have to check circuits to relay, if no voltage.
Was this
answer
helpful?
Yes
No
Monday, March 29th, 2010 AT 3:35 PM

Please login or register to post a reply.

Recommended Guides