Jeep cranks, but won't start. I've tried many of the typical things.

[TheManWithNoName]

I already emailed them on Friday.

Hope you fix your problem quickly! At least now you now what could be the issue.

 

[macleanflood]

I already replaced the camshaft position sensor and still have the same problem.

Have you verified the wiring from the sensor to the PCM? Have you checked for 5v on the connector? Are you certain your new part indeed works?

-Mac

 

[DevilDogDoc]

Is your ASD working right? Mine did the same thing once and I had a break in the ground to the ASD. I spent too much time on other stuff before that.....

 

[JasterMereel42]

Here's an update.

1. Sent the PCM to Wrangler Fix and they verified that the PCM is good
2. The ASD relay is good because I swapped it with another relay and the Jeep wouldn't start
3. The INJECT fuse is good because I swapped it with another fuse and the Jeep wouldn't start
4. I confirmed that the fuel rail is getting about 45psi
5. I confirmed that the fuel injectors are not getting power by connecting a node light to them and the light was off
6. Camshaft position sensor was replaced, I still need to double check that the new one is good

At this point, everything is pointing to the fuel injectors not firing for some reason. I will continue chasing wires and grounds to make sure everything is good, but this is getting frustrating.

 

[JKP]

You should have 12V at the injectors, the PCM pulses the grounds.

 

[DevilDogDoc]

So the ASD relay should have power and ground on the different terminals. I would look hard at that before digging much more. Mine had corroded under the loom and broken through.

 

[JasterMereel42]

So the ASD relay should have power and ground on the different terminals. I would look hard at that before digging much more. Mine had corroded under the loom and broken through.

yeah, that's on the list of things to check once I get time to keep poking at this.

 

[JasterMereel42]

I got the Jeep running again. It was the CRANKshaft position sensor.

I've been watching all kinds of videos trying to find a clue what to do. I ended up watching this video by Garage Couple where they are diagnosing ASD issues.

Here are the steps that lead me to figuring this out from the video.

1. Pull the ASD relay
2. Put in a piece of wire to directly connect the constant 12V and the ground
3. Try starting it
4. If it doesn't start, then it is likely the camshaft or crankshaft position sensor.
5. If it does start, then it is something else like a bad ASD, bad wiring, bad ground, etc.

In between work meetings today, I used a piece of wire to bypass the ASD. It didn't start after that. Since I had already replaced the camshaft position sensor, I ordered a crankshaft position sensor. After work today, I replaced it and it started up.

For those that may be reading this months or years later, the CAMshaft position sensor is on the engine block, usually on the passenger side. The CRANKshaft position sensor is on the bell housing of the transmission. I even found some websites that get the 2 parts mixed up.

Took me awhile, but I figured it out. Thanks to everyone here that provided helpful advice.

 

[OurTJs]

Same problem here. Starting fluid doesn't make it fire. No spark. Crossing the pins at the relay runs the fuel pump. When I pull the one 30amp fuse the fuel pump runs constantly. New complete distributor, coil, crankshaft sensor, wires. No check engine light. No link error when putting an obd2 reader. Done the gauges test and all gauges and lights work. There's power to the obd2 plug. Checked all the connectors and there doesn't appear to be any frayed wires etc. All fuses are good and relays are good too. 45 pounds fuel pressure at the fuel rail. Ignition switch or pcm? Im stumped. Sound familiar to anyone?