i have no idea why my jeep grand cherokee isnt starting, it is a 1994 4.0 6liter engine, does any one have any ideas why this is happening and what i can do to fix it? and if this is the wrong place for this let me know,

 

give more info about what it does when you turn the key?

 

i hear the fuel pump turn on and it cranks but no start

 

did you check the crank sensor?

 

Its new

 

Mine ran fine on monday and tuesday it wasnt getting spark to #2,
Did you check for spark?

Did it not start after CPS replacement?

check to make sure there is fuel in the cylinders, pull some plugs after crank to make sure your getting the gas to the spark(if there is spark)

 

1. Checking for spark is absolutely job #1. Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground. Have a buddy crank the engine over while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white spark is weak, which may be caused by a failing ignition coil.

2. If spark is good (and only if) then introduce a small splash of gas or starting fluid into the intake. If the engine starts and runs for a few seconds, you have identified a "fuel delivery problem".

The above are quick and dirty tests that anybody can easily perform and the results of those tests go a long ways in knowing what to look at more closely.

Good luck and keep us updated!

 

No spark. New coil

 

It did then it stopped running

 

When you say " it did" do you mean it ran for a few seconds when gas was put into the intake ??

Do you have 12 volts on the coil primary when the ignition/key is on ? The 12 volt buss voltage comes through a few things before getting to the coil, I believe..
Crankshaft position sensor is also in the mix, so if it's bad...no workie....and the ASD relay ( auto shut down ) relay also supplies power to the coil..

 

Spark: 12 volts from ignition switch to the ASD relay; when the key is first turned on the PCM provides a ground to the ASD relay to energize it, then the ASD relay passes 12 volts to the coil primary side. If no crank sensor signal is generated after a couple of seconds the PCM cuts the ground to the ASD relay (and fuel pump relay too) and that cuts power to the coil (and fuel pump). Key to START and once again the PCM energizes the ASD relay. Now, a critical element is the crank sensor--no signal from the crank sensor and the PCM won't trigger the coil to provide spark.

 

Im getting 12 volts off the ground on the coil

 

I mean after the new crank sensor it ran for a few days then it died, but it ran very rough