Justin Schneider

03 Jeep Grand Cherokee v6 4.0 had a lot of problems with his so far but just replace the crankshaft sensorand also took off the throttle body and clean that with throttle body cleaner and we connected everything and now it won't start I put it on a cheap computer saying and it grew to code manufacture something P1 139 or something
And and the other one was p0304. But now it will not start at all like I said I've already put a new crankshaft sensor and new spark plugs cleaned out the throttle body. Should I replace the crankshaft position sensor also

dave1123

Did you remove the Throttle Position Sensor, Manifold Pressure Sensor, and the Idle Air Control from the throttle body before you cleaned it? You may have damaged one or more of them if you didn't. The best sensors you can buy are Mopar and even though they cost more, they are far better quality than any aftermarket ones you can buy, which don't last very long IF they work at all. It's not uncommon to have one be bad right out of the box, especially if it's Chinese. This is especially true for Crank sensors. Before you go firing the parts cannon at it, there are continuity and resistance tests you can do to see if they are good or not before you buy new ones. Sometimes there could be a wiring fault or a bad plug connection. Of the 3 wires that are on the Crank sensor, one is power, either 5v or 12v with the key on (I'm not sure which), one is ground, and one is signal, which will flash a test light or bounce a meter needle when the crank is turning. If you are really good, it shows a square wave form on an oscilloscope. You can "backprobe" a connector by inserting a pin into the side of the connector where the wires come out to make contact with the terminals inside. OR you can empty your wallet throwing parts at it. Your choice.

That's not a V6. It's a straight 6 or I6, whichever way you like.