Dumba** needs jeep motor help

mike davis

New Member
Joined
Jul 25, 2017
Location
Fayetteville NC
Hello all,

I have a 2002 TJ with the inline 4 motor. 130xxx miles.

Issue I'm having, jeep wont start. And is throwing P0340 error code. Crank shaft position sensor(AutoZone says my jeep doesn't have a CPS. . .) I can hear the starter trying its hardest, but no ignition. And that's only because I Just replaced the starter, last week. We thought it was an issue with the timing on the distributor, double checked that, wasn't the issue. Tried giving a little boost with some starting fluid and now I need a new airbox from the gnarly backfire that caused.

In the last month I've (with help, lots of help.) replaced the Serpentine belt, driver side pulley, and the serpentine belt tensioner assembly, rear main seal, oil pan seal, clutch, shaved the flywheel, camshaft sensor, complete distributor, And starter. I checked my plugs and wires they are not in need of being replaced. The current engine was replaced by a shop in Alaska in 2014(15xxx miles on it.).

I have no idea what wrong at this point, and neither do my more mechanically inclined friends. Im not sure whether I need a mechanic or a priest at this point.
 
Not sure on your tj but I know on a yj with the 4cyl the cps was located on the driver side of the engine/bellhousing around the 10 o'clock position.

Quick Google search showed a video of a guy with a tj showing his in the same location.
 
Jody, No I have not yet replaced the CPS because I have not been able to source one locally. And yes the 02 2.5L I4 has a distributor, passenger side of the motor. wanna say its sits over the oil pump.
 
Jody Treadway said:
Have you replaced the crank position sensor?
You don't have a distributor on an 02, so what did you double check?

2002 JEEP WRANGLER 4.0L L6 Crankshaft Position Sensor | RockAuto
Click to expand...
mike davis said:
Jody, No I have not yet replaced the CPS because I have not been able to source one locally. And yes the 02 2.5L I4 has a distributor, passenger side of the motor. wanna say its sits over the oil pump.
Click to expand...


ignore my last. I Have replaced the crankshaft position sensor, I have not replaced the Camshaft position sensor.
 
Make sure the dizzy is indexed correctly, then replace the crankshaft position sensor again.
 
Sorry, I missed the 4 cyl line.
So you do have spark if it backfired and blew up the airbox. That means you probably having a timing issue.
Are you positive you reinstalled the distributor correctly?
 
Make sure the distributor is indexed correctly. They don't install like old school "#1 DTC point the rotor at the post" ones did.

Unplug the coil connector, Take a paper clip and jumper between the pins.
Take a test light and connect it to the negative battery post. Attach the other end the jumper wire.
Crank engine and Observe

A- the test light flashes but no start mean the crank sensor is functional but the coil isn't firing. Verify power and ground at coil and report back.
B- the test light does not flash means the crank sensor is not grounding and ungrounding the coil. Replace crank sensor
 
Last edited:
Also pull the oil cap and have someone crank the jeep. Make sure the valves are moving. 2.5's are bad about timing chains stretching and breaking.
 
Back
Top