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  #16  
Old August 11th, 2018, 08:19
deproson deproson is offline
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2000 XJ wont fire

Yes the Zeus is also a scope. I have looked at the waveforms and they appear to be where they should be. Iíll take a look at the link you posted. Thanks.


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  #17  
Old August 11th, 2018, 08:53
CJR CJR is offline
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Re: 2000 XJ wont fire

Tim MN,

With all due respect. Heat from the exhaust manifold can indeed cause vapor-lock in the fuel rail(i.e. liquid fuel gassing off to form a bubble of gas to block liquid fuel flow and/or flow of a mixture of vapor and liquid to the injectors). Mixtures of vapor+ liquid to ejectors randomly screws-up the fuel delivery to each cylinder. In some cases, some cylinders can randomly run lean because less weight of fuel is being supplied to them in a random fashion. I agree that a typical FI engine can clear vapor blockages quickly. But anytime you have a non-insulated fuel rail positioned over the very hot exhaust headers(i.e. XJs), on a very hot 105F day, vapor-lock/vapor flow is going to cause fuel supply issues. Also, the term "heat-soak" is normally used to define heat-flow into starter motors after shutdown which then cause hard-starting during a quick restart. The "heat-soak" I'm talking about is the heat flow into the fuel-rail to vaporize the liquid fuel.

Any way, we'll have to agree to disagree on this point.

Best regards,

CJR
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  #18  
Old August 11th, 2018, 12:12
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Tim_MN Tim_MN is offline
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Re: 2000 XJ wont fire

Heat Soak is the phrase commonly used by XJ Cherokee owners to describe a specific start-up behavior in 2000-01 Cherokees.

My 2000 runs well, as does another 2000 and an 01 in my local Jeep club. All three have a faulty check valve and will loose fuel line pressure on hot days when not running, both on the road and on 4x4 trails, but none have any running issues after starting and clearing the small amount of vaporized fuel in the fuel rail. None of the three set trouble codes either. All three also will idle evenly and uneventfully for long periods of time under the same conditions.

YMMV.
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Last edited by Tim_MN; August 28th, 2018 at 10:33.
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  #19  
Old September 14th, 2018, 16:03
deproson deproson is offline
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2000 XJ wont fire

Update:

My jeep is finally running after going through multiple OEM crank sensors. Keeps runs great now but I now have a different issue.

The issue that I have now is that after I did a hard reset on the ECM I can drive 80 miles with no problem. Then after I go 80.1 miles I get a check engine light then a flashing check engine light.

Checked DTCs

Cylinder 1 misfire
Cylinder 2 misfire
Multiple cylinder misfire

I have a spare good working ECM. Plug it in and can go another 80 miles problem free.

So is there anyone out there that can make any sense of this? I have never ran across anything like it.

Any help would be appreciated.



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  #20  
Old September 15th, 2018, 07:15
alwayzAMC alwayzAMC is offline
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Re: 2000 XJ wont fire

is your scammer able to pull live data, my snapon verus has a mode where you can watch just misfires, i wonder if you are getting missfires all along and it is just after 80 miles the CEL shows up, or if your misfires are starting after 80 miles, if you can get to a misfire counter mode maybe you can drive around with it connected. i know on GM's and fords the flashing CEL means a very bad misfire condition, i am not certain if chrysler is the same or not.

also on my 2k i am also having issues in with the sync i dont know what that data means, it bounces back and forth, but mine runs perfect,
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