Real problem's now Help

#1
I have a 2002 TJ 4.0 Litre 5 speed manual trans
The check engine light comes on then after a little more driving the check gauges , 4wd , and other dash lights will flash off and on ( while this happens the check engine light goes off and on at the same time ) . The code it gives is a P1391 ( cam / Crank postion sensor ) . So far i replaced the battery and the terminal ends for the battery , I found the starter wire loose last week and tightened it up and drove about 200 miles and it came back on and started the same thing as before . I have had some one sit in the jeep while it is running while i shook the wires to the ECM , and ground wires and alt / starter wires . all the grounds on the engine and firewall are tight .
I am at a loss and not sure what to do now . Thanks for any help Dave
 
#2
Well i just ordered this ,,,OBDLink SX Scan Tool USB Interface w/ OBDwiz Diagnostic Software ,,I am hoping i can drive with this hooked up and look for any voltage issues ,,,What do you all think?
 
#3
I would consider pulling the dash guage cluster and clean the plug terminals. When you re-attach the plugs apply a little die-electric grease to ensure you have a good contact. I would also disconnect the PCM plugs, clean the terminals, and apply some die-electric grease.
 
#5
I didn't replace any sensors yet , I am going to order the crank and cam position sensors from the dealer , Would one of those sensors going bad cause the flickering lights on the dash ?
 
#6
I didn't replace any sensors yet , I am going to order the crank and cam position sensors from the dealer , Would one of those sensors going bad cause the flickering lights on the dash ?
Sounds like a bad connection to me but, it could be both a bad sensor and a bad dash connection, weirder things have happend. I would inpect and clean all the connections first and see what that does. If they stop flickering and the check engine light still pops a code well, replace the sensor. Before you pay dealer prices for the sensor check Rock Auto.com or similar, dealer is pretty pricey..Rock Auto crank position sensor for MT $64.00
 
#7
rock auto has the sensors , any recommendations on where i should get them ? , or which one i should get from rock auto , they have 4 different one from 29 to 54 dollars
 
#8
Crank sensors are the most common thing to crap the bed on a 4.0, followed closely by cracked exhaust manifolds.

The "throw parts at it" method would start with replacing the crank sensor. If it's not bad now, it's just a matter of time that it will if it's the OEM sensor. Then check/clean your battery cables. Then pull the cluster(it's easy) and check/clean the connectors there.
 
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