I have a 1996 dodge caravan that has a 3.0
I have code p1390 and it runs rough at initial movement and up around 70mph. When I start the car it takes a minute.
I just recently changed the Distributor cap and rotor. But i don't know if this effected it. I read that the p1390 could be the camshaft position sensor and with this engine it is part of the distributor.

Should I just replace the distributor (big part for big money) or is there a way that I could take apart the sensor and clean it out or something? Or any other advice would be much appreciated.

 

clear codes and re run the vehicle, you could have a bogus code like if someone unplugged a sensor when the key was on.

these vans with the 3.0 have been known for exhaust valve failure. I've had over 20 in the past 6 years. most were #5 cylinder. do a quick compression test. if you remove the wiper module (15min job) it makes access very easy.

 

Welcome to DF
P1390 is a real code.Its timing belt skipped 1 tooth or more. Clear the codes and see if it comes back. When was the last time the timing belt was replaced?

 

I'm sorry it is P1391 I'm really sorry because the skpping 1 tooth or more thing was one of the possible issues too. It has something to do with the camshaft position sensor or timing. I don't know when the last time it was done. I just bought the car 4 days ago. Gotta love lemons!

 

Here are some of things that can be the problem. If you want the rest of the pdf file just let me know and i will send it to you by email,so i will need your email to send it too,If you want.
Symptom:
P-1391 INTERMITTENT LOSS OF CMP OR CKP
When Monitored and Set Condition:
P-1391 INTERMITTENT LOSS OF CMP OR CKP
When Monitored: Engine running over 7 seconds.
Set Condition: When the expected cam signal level disagrees with the actual cam signal
level.
POSSIBLE CAUSES
CKP SENSOR CKT WIRING HARNESS INTER DEF
CMP SENSOR SIGNAL CKT WIRING HARNESS INTER DEF
CAMSHAFT POSITION SENSOR DEFECTIVE
CAMSHAFT SPROCKET DEFECTIVE
CRANKSHAFT DEFECTIVE
CRANKSHAFT POSITION SENSOR DEFECTIVE
DISTRIBUTOR PULSE RING DEFECTIVE
FLYWHEEL DEFECTIVE
CAMSHAFT TARGET MAGNET DEFECTIVE
CAMSHAFT THRUST PLATES(S) NOT ATTACHED
CKP SENSOR CONNECTOR TERMINALS OBS DEF
CKP SENSOR CONNECTOR TERMINALS OBS DEFECT
PCM CONN TERMINALS OBS DEF (CKP SENSOR)
PCM CONN TERMINALS OBS DEF (CMP SENSOR)
CAMSHAFT/CYLINDER HEAD DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition Off.
At the CMP Sensor, backprobe the CMP Sensor Signal Circuit with the Oscilloscope
voltage measurement lead.
Start the Engine and observe the CMP Sensor voltage pattern on the Oscilloscope.
Are there any of the Camshaft Position Sensor Signals missing?

 

I brought it to AAMCO for their free check and they say they monitored the Camshaft position sensor and the crankshaft position sensor and he said they were in sync. THen he told me that he read on some sort of mechanic blog that the problem is 90% of the time the camshaft position sensor which would require the replacement of the whole distributor.
So I guess the next piece of info I have is that it is intermittent. I will try my best to test it the way it is described by Master Tech.
Any other advice or experience would be much appreciated.

 

it is very rare (pretty much unheard of) to have a cam or crank sensor cause the rough running conditions you described. in my limited experiences, it's either they work or dont work. if a cam sensor is bad, it won't run, if a crank sensor is bad it won't run.

cam timing sure would cause running problems, that's a mechanical issue. I've had a 3.0 van come through that someone put a belt on and one tooth off on cam and it didn't set a code.

Don't forget the mechanical basics. too many times I see guys chasing codes and computers etc, all caused by a mechanical issue.

 

So what should do? What's the first things I need to check when I do a mechanical check? Do I check the timing? What will let me know if it jumped a tooth? Can you give me some description on this one because I am a newbie when it comes to timing, etc.

 

I told you what to do in post #2. I don't know that my english is that poor where doing a compression test is a foreign language. A compression test will show if cam timing is off also.

get yourself a shop manual for quick, accurate and complete information. If you can cook following directions in a recipe, you can fix your car. the shop manual is the cook book for your vehicle. If you were making a cake, wouldn't you follow the directions on the box?

 

Wow I can't believe I missed that. I think i skipped over the instructions since I originally wrote down the wrong code. What you say makes a lot of sense. For instance a day before the light went on I was changing the cap and rotor. And you can can only unscrew the rotor at a specific angle. So I took the cap off and turned the key (very shortly) to get the rotor to turn enough so I could detach it. Could this have set off the code?
Now I will pursue what you're saying. It would make a lot of sense. Or maybe it just needs some babying since it has been sitting. I'll be away from the car for a week (visiting family) so I can think about what I will do all week.