'06 Liberty 3.7L P0340, P0344, P0508

[ghause]

Ok guys need some help after reading thru everything I could find doing a search.

A few months back the Lib started doing the crank no start that several people have had an issue with. Didn't matter if the temp outside was cold or warm or if the Jeep itself was cold or warm. Anywhere from 5-20 attempts at trying to start it, then it would finally start. 2 codes always present were the P0508 and P0340. Changed cam, crank, map, and IAC sensors to no avail, Swapped the ASD relay and there you go problem gone for 5 months. Then yesterday it shows up again and brought its friend P0344 along.

The first thing to happen was I accelerated from a stoplight and it started the bucking, limp home mode I am assuming max RPM I could get was about 2,500. Got it home shut it off and said I'll get it to the parts store and get the code pulled. Drove it to another store first had no issues at all, come out and it wouldn't start. It took about 20-30 tries and it finally started so went to parts store got codes pulled and those 3 were there. Figured well it's another ASD relay, bought one put it in, started up just fine, drove no problems stopped at the next store and no start. On the way home the bucking showed up again. Started checking everything again and did find some oil on the connector for the Cam sensor, disconnected, cleaned, pulled harness out and inspected nothing else found other than a piched O-ring for the cam sensor. Replaced the O-ring put it all back together, disconnected the battery to clear the codes and it started right up. Drove it and it was just fine for the first couple of miles and then started the bucking again and actually died while I was driving, turned the key off, it started right back up. Drove it back to house, went to parts store rented a scanner and P0344 was there along with 2 knock sensor codes that I think are completely unrelated and were just a result of me trying to see if I could get it stop the bucking.

So with all of that said, I have read a lot that says OEM for the crank and cam sensor, still have those and will try to put those back in tomorrow since I am thinking they may still be good. If the 340 and 344 still persist my only options left that I can think of from what I have read is, ECM (possible but unlikely), timing issue of some sort (possible but again unlikely as it runs smooth as silk), tone ring (most plausible????).

Any thoughts or ideas would be much appreciated.

 

[Billwill]

Sounds very complex!

The fact that things improved every time you replaced the ASD Relay could point to a problem in that area.

Clean the female contacts inside the relay socket with some fine Emory Paper and slightly bend the female contacts inwards in case they have lost their tension and are no longer biting firmly on the male relay contacts.

Flip over the relay box under the hood so as to inspect the wiring coming into the ASD relay area.....could be a badly crimped lead on one of the female contacts and the wiring may show some damage in that area. I know on my CRD I had to remove the battery to be able to flip the relay box and inspect the wiring and did find a problem with a crimp on the one wire going to the ASD relay.

You can try removing the ASD Relay and fit a jumper wire between female pins 30 and 87.....this does not Hot Wire the Jeep but provided the SKIM system is working you should be able to start and run the Jeep like this!

Also worth checking the pins at the PCM connectors for any dirty or burnt contacts and check the wire harnesses wherever you can get access to them for chafing to chassis/engine.