TJ2
TJ Expert
Reason why I question that is that TJs are very common to have OPDA issues. Oil position sensor is what I questioned from his sentence.
TJ cranks but will not start
- Thread starter Milrz
- Start date
TJ2
TJ Expert
I believe that you have CPS or alternator problem if you just drove it before it give you that problem.
start with the basics. Look at all your wires near the oil position sensor. Your wires for your starter and your distributor are in that area. At least they are on my 4 banger. check your connections and look for broke wires. then check for melted wires near the block.
It very easily could be a crank shaft position sensor. I had one just stop and then I replaced it with an after market one (none OEM) and it went out in a few weeks and then I melted the wires on another one. At least they are easy to change LOL. I have also had relay issues where the engine does nothing when I turn the key. I sprayed out the engine compartment fuse holder with some aviation contact cleaner and took the relay apart and cleaned it. That fixed the problem.
Stay calm and wrench on
It very easily could be a crank shaft position sensor. I had one just stop and then I replaced it with an after market one (none OEM) and it went out in a few weeks and then I melted the wires on another one. At least they are easy to change LOL. I have also had relay issues where the engine does nothing when I turn the key. I sprayed out the engine compartment fuse holder with some aviation contact cleaner and took the relay apart and cleaned it. That fixed the problem.
Stay calm and wrench on
Tonight I will be installing crank shaft position sensor. I will also check for spark, the oil pressure sensor has been replaced. I am just so puzzled cause I drove it in the garage and even started it in the garage a few times to check gauges etc....
TJ2
TJ Expert
Last edited:
boostedv6
Member
Yes. Go back to basics. It was running before you changed the oil pressure sensor. Start there. Why did you need to change it in the first place? Can you restore it to the point you were at when you thought you needed an oil pressure sensor?
First question is 4.0 or 2.5 engine, may have missed it in all the confusion. You said you got a code reader. Personally I would stay away from anything that connects to your phone, I’ll go look and tell you what I have in a min. It works great, they are probably a good I vestment for these Jeeps. Lastly have you tried jumping the oil sensor with a paper clip just to see it run? Might not be your problem, but with so many computers a lot of times these engines won’t run when they could, because they are scared by a sensor. I had a Defunct coolant sensor that caused the Jeep to not start, if it wasn’t for the code reader and the help from tj forums, I would probably still be trying to figure it out.
I ordered a new one installed and plugged it in it fit like a glove but not sure if it works or not it is brand new
I bought a code reader and it plugs in and scans it says will not connect please turn key on make sure obd2 and restart but it will not connect. It is a stand alone reader not a Bluetooth. Also 4.0
So I was installing a oil pressure gauge and the sensor snapped in half when I unplugged like it was brittle. I was doing a gauge cause my oil pressure on dash was acting weird. I ordered a new sensor installed and threw the gauge away cause I said forget it if this is gonna be a issue.
I assume you have verified all the things it asks for, such as key On run position but not running (not really a problem rn) I have an old autel unit that I got from a friend. (See pic below) I have heard that autel’s are generally regarded as the best readers but that’s just hearsay. Snap a pic of your unit, it could be to new to I terrace well with the TJ’s also, have you tried to by pass the senso all together, like jump the wiring at the connector to see if your new oil switch is good?
So, this is my opinion, but I'd ditch that aftermarket oil pressure sensor for an actual Mopar sensor. For some reason, our TJ's seem real sensitive to sensors, and OEM is the only way to go. That aftermarket one may not be giving the ECU the output its expecting, therefore not allowing the engine to start.
Sometimes I wish for the good old days, when all you needed to verify was Fuel, Compression, and Spark. If you have those three things, the engine will run. Now, with the sensors and computers, its a bit more challenging. The same basic conditions need to be met (Fuel, compression, spark), its just that the troubleshooting chain is longer. The computer can turn off the ignition for a number of things. I believe that oil pressure switch is one of them.
Sometimes I wish for the good old days, when all you needed to verify was Fuel, Compression, and Spark. If you have those three things, the engine will run. Now, with the sensors and computers, its a bit more challenging. The same basic conditions need to be met (Fuel, compression, spark), its just that the troubleshooting chain is longer. The computer can turn off the ignition for a number of things. I believe that oil pressure switch is one of them.
And my code reader
I am sort of new to the sensor thing I need help with the jumping to check issue. I have this scanner
Un-plug the connector and take a picture of it, might be able to figure something out, if it’s just 2 wires jump them, but it’s probably 3 Because of the gauge which will get more Interesting.
Also there are a few threads on OBd2 readers, worth researching for a good one. Personally I would buy an autel; but that’s my personal opinion, there a little more pricy but they last, and work well. don’t be drawn by features you don’t really need. Some people report good outcomes with the Bluetooth ones, I don’t like them. But that’s just my opinion from time as a shade tree mech.
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