Help! Just turned off when driving
Thread Starter
Seasoned Member
Joined: Dec 2011
Posts: 250
Likes: 1
From: Bozeman, MT
Year: 1997
Model: Cherokee
Engine: 4.0 inline 6
Was driving everywhere last night no problems then this morning get going and she just stops at the first light I hit the breaks and she turned off now it'll turn over but seems like no spark or anything any suggestions
Trending Topics
Unplug it from the harness and probe A and B (on the CPS side, not the harness side) with a multimeter set to AC volts (yes, AC). With the engine cranking (it won't start) you should read 0.5v AC. Anything under ~4.5 and your CPS is suspect.
Also, just unplugging and replugging sometimes clears the issue.
Also, just unplugging and replugging sometimes clears the issue.
You could just check for spark as well, whatever technique you prefer as there are many. Starting fluid in the throttle body, tongue on spark plug wire (<<<that's a joke, don't do that), pull a plug and ground it while cranking, probe the coil... like I said, lots of ways.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Unplug it from the harness and probe A and B (on the CPS side, not the harness side) with a multimeter set to AC volts (yes, AC). With the engine cranking (it won't start) you should read 0.5v AC. Anything under ~4.5 and your CPS is suspect.
Not sure a 97 checks the same way our old Renix rigs do....
Also, just unplugging and replugging sometimes clears the issue.
Not sure a 97 checks the same way our old Renix rigs do....
Also, just unplugging and replugging sometimes clears the issue.
CF Veteran




Joined: Nov 2010
Posts: 5,841
Likes: 117
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
I approach every no-start in the same way.
First, check for spark.
Pull a spark plug. Keep it attached to the plug wire. Place the plug electrode near a good engine ground. Have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark, which may not be strong enough to start the engine.
If spark checks out (and only IF), try a small splash of gas into the intake or a small shot of starting fluid. If the engine starts and runs for a little bit using this technique, you have identified a FUEL DELIVERY problem.
The above two tests are quick and dirty but are extremely valuable in isolating root cause here.
Do NOT throw parts at this on a hunch. You will likely be wrong and your pocketbook will suffer for the guesswork. Test your way to a solution here.
Good luck and keep us posted!
First, check for spark.
Pull a spark plug. Keep it attached to the plug wire. Place the plug electrode near a good engine ground. Have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark, which may not be strong enough to start the engine.
If spark checks out (and only IF), try a small splash of gas into the intake or a small shot of starting fluid. If the engine starts and runs for a little bit using this technique, you have identified a FUEL DELIVERY problem.
The above two tests are quick and dirty but are extremely valuable in isolating root cause here.
Do NOT throw parts at this on a hunch. You will likely be wrong and your pocketbook will suffer for the guesswork. Test your way to a solution here.
Good luck and keep us posted!
Thread Starter
Seasoned Member
Joined: Dec 2011
Posts: 250
Likes: 1
From: Bozeman, MT
Year: 1997
Model: Cherokee
Engine: 4.0 inline 6
Found out its the cps for sure got one with a lifetime warranty for 85 not bad will throw it in tomorrow and hopefully take her out as well
Member
Joined: Aug 2011
Posts: 102
Likes: 0
From: Centreville MI
Year: 1988
Model: Cherokee
Engine: 4.0



