91 cherokee fuel pump wont come on
11-25-2012, 08:18 PM
#1
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Model: Cherokee
91 cherokee fuel pump wont come on
I got a 91 cherokee the fuel pump wont come on the relays are good the pump will come on when you ground one of the prongs in the test port on the ecu under the hood everything else looks fine like fuses and relays please help
11-25-2012, 08:43 PM
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Year: 1988
Model: Comanche
Engine: AMC 150
http://jeep.zerok.ru/index.php?page=196. Should tell you where your power is supposed to come from. Start at E5-6 IAW identification table and trace it to find relay trigger.
Hope you find your solution
Hope you find your solution
11-25-2012, 11:03 PM
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
There is a ceramic resistor for the pump on the drivers inner fender there by the air cleaner. Bat voltage comes in the front, and a few volts less goes out the rear, directly to the pump. It's mostly to quiet the thing. You can bypass or eliminate it if you want. You might check that. 
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11-26-2012, 04:27 AM
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Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Test light check for power to pump at tank it will only run for a couple of seconds have some one cycle key while probing wires .
11-26-2012, 11:12 AM
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Model: Cherokee
Cause i always here it run when i turn the key on now it wont start got no fuel pressure and if i ground one of the tabs on the test port for the ecu it will turn on it ran but i pressure washed the engine bay it wouldnt start up and thats when i found out the pump wont comming on
11-26-2012, 01:51 PM
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Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Ya gotta start testing from pump work backwards theres not a over the net fix with out testing ....
11-26-2012, 02:15 PM
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11-26-2012, 02:57 PM
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Model: Cherokee
I checked fuses and relays i changed the ignition switch but on the computer there is the L shaped data test port and if i ground top right prong with the key on the pump will come on but i also checked and i do not have fire either could this be the computer bad or is there a way to test the computer