cranks but won't start

[bradleyheathhays]

So I got this '96 Jeep Cherokee XJ that cranks but doesn't start.  It's got around 180k on her but I keep everything in good shape.  Batt seemed strong.

I used to drive it everyday but this past year I've driven it only about twice a week.  It's been just slightly slower to start in the last couple of months, but just barely slower.  Was guessing it had something to do with aging plugs or something.

Drove it yesterday and everything was normal like always, sat overnight and today it cranked but didn't catch.

Any ideas on where to start?

[06kfx440]

So I got this '96 Jeep Cherokee XJ that cranks but doesn't start.  It's got around 180k on her but I keep everything in good shape.  Batt seemed strong.

I used to drive it everyday but this past year I've driven it only about twice a week.  It's been just slightly slower to start in the last couple of months, but just barely slower.  Was guessing it had something to do with aging plugs or something.

Drove it yesterday and everything was normal like always, sat overnight and today it cranked but didn't catch.

Any ideas on where to start?
[/quote


Try checking your alternator and voltage. What about your fuel injectors and fuel filters. Do you have a 30 bar psi gauge?


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[davefrombc]

Start by  making sure you  have  spark  and fuel pressure to the injectors..

[Frank Angerano]

I would guess that your coil is getting moisture inside and that’s why it’s been getting worse.   I would throw a new coil and wires with some new plugs.   Def check fuel as @davefrombc said as well. Maybe a new fuel filter wouldn’t hurt too! 

[06kfx440]

Hey guys. This is a 96 Jeep. Not a quad or snowmobile. The only time to check the carb out that way is 87or older Pre obd 1


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How is your compression, any check engine lights?



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[Frank Angerano]

Yep seen that in the first post.  I’m still sticking with my original diagnosis of a coil, wires and plugs.   

[davefrombc]

28 minutes ago, 06kfx440 said:

Hey guys. This is a 96 Jeep. Not a quad or snowmobile. The only time to check the carb out that way is 87or older Pre obd 1


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How is your compression, any check engine lights?



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I don't see anywhere we mentioned anything about a carb.. I  suggested  checking fuel  pressure to the  injectors.  If your fuel pump  isn't delivering adequate pressure either due to a failing pump or plugged  filter   the vehicle will  be  hard starting  and running poor ..  As Frank  said ,  moisture in the coil or  other components of the ignition system  could  cause erratic  spark.

If it is getting fuel  and  spark , then the problem is in timing  or  other mechanical problems.  One thing that is  often  overlooked   is the possibility  of a plugged catalytic converter  causing running problems.

Edited September 6, 2019 by davefrombc

[bradleyheathhays]

So far I've been able to run a couple tests..

Hooked up a fuel pressure gauge and first key turn got it up to only 20psi. Second turn got it up to 45. And third and subsequent turns got it up to 48. It only fell to 43 after 2 minutes so I think that means the fuel pressure is good.

Hooked up a spark tester between a plug and wire and it didn't light at all when cranked so I'm guessing I've got a spark problem. I'll start by doing a tune up with new rotor, cap, wires and plugs then see what happens.

[Ajmboy]

5 hours ago, bradleyheathhays said:

So far I've been able to run a couple tests..

Hooked up a fuel pressure gauge and first key turn got it up to only 20psi. Second turn got it up to 45. And third and subsequent turns got it up to 48. It only fell to 43 after 2 minutes so I think that means the fuel pressure is good.

Hooked up a spark tester between a plug and wire and it didn't light at all when cranked so I'm guessing I've got a spark problem. I'll start by doing a tune up with new rotor, cap, wires and plugs then see what happens.

Good diagnosis. My first guess was fuel but since you got pressure and also found no spark, replace those plugs, wires, cap and rotor to start.