Installed rebuilt engine last night. No spark, no fuel injectors. Tested for power at coil plug, no power at all. traced wire back to PCM for a continuity test and is ok. I have issue with crank sensor so tranny has to come out. Bolts that hold clutch pressure plate on to long and busted crank sensor. BUT!! that should not stop the pcm sending 12volt to coil. Besides, the sensor is still good just no way to mount it now. This truck I bought came as a basket case, so its like starting from scratch. Oh by the way, does it has to have oil psi to have spark? Like a GM. Its only a 2 wire oil psi sensor for gauge but I thought I would ask.

 

if the pcm doesn't see a signal from the crank sensor within 3 seconds, it trips the asd relay, and there will be no power to the coil, or injectors.

Nope, the engine will run fine with zero oil pressure. At least... for a little while....

GM's will too. Look at the wiring diagrams. The oil pressure sensor is backup power for the fuel pump, that's it. No low pressure shutdown capability at all. (I have been thru this one more times than I can count.)

 

Do not buy anything other than OEM crank and cam sensors!!!!
I pinched the wires to the crank sensor on my truck putting the tranny back in.
Replaced it with a Napa crank sensor, that’s when the fun began!!
I would start my truck it would run anywhere from 6 to 8 mins and it would just die.
I would wait about 60 seconds and it would start back up.
I could go where ever I wanted shut it off and start it back up and no issues,
unless I let it completely cool down again.
We checked everything over a period of about 6 months finally decided to replace the crank sensor even tho it was brand new.
I replaced it with OEM and haven’t had any problems since (8 months).
NAPA SENSORS ARE GARBAGE PERIOD!!!!!
Use OEM Only they are not much more then Napa sensor and none of the grief.
This is where I got mine http://www.moparonlineparts.com/.
They were cheaper than my local dealer.
Call the toll free number, have the last 9 numbers of your VIN ready and they will get you exactly what you need.
I was very happy with the service and the price was the best around.
I have used them several times for the 4 dodge trucks I maintain.

Dave

 

Well just got back and I was probably learning as Hey You was typing. Found that there is only power to the coil as signal is received from crank sensor. Weird , but ok. Napa sensor junk? I have really never had a problem with Napa stuff. At least they will take it back, at least in my case. Remember attitude is everything. Even when trying to return something. As far as what I call fly by night places like Advanced auto, O riles auto and even walmart "never start" battery's and stuff they are "ok" . I have had things not work right from Napa,like alternators, or even there Chevy's funky distributor caps in the mid late 90's were faulty. But when it came to returning them and talking to them they all ways made it right with me. And I all ways keep in mind "just because its new doesn't mean that it works for sure". No I don't work for Napa. Silly but I work for Ford and drive a Dodge to work. Well I'll pull trany some other day. Needs cleaned up anyway. And has a bad u joint in front drive line. Which I will replace with a triple seal Spicer that I will buy from Napa because you have to problem special order them from Advanced or O Riley. That is even if they know what i'm talking about....lol thanks

 

Thanks for that website info.That may be some of the issue I have as well. Do you have the Mopar crank sensor part #. I did a search for crank sensor an got no results. I put a BWD brand crank sensor from advanced auto in my truck and it will idle along fine while i let it warm up in the morning and after 10 or so minutes just shut off. starts right back up and is fine. But when my engine is cold it will cough through the TB till the thermastat opens. then it runs great.

 

Yeah they took mine back too even after six months.
I buy other parts from them all the time.
I've just learned my lesson on sensors with the dodge trucks OEM or forget it.

Dave

 

Bad crank or cam sensor can do all kinds of crazy stuff.
Like I said it took lots of testing to find out it was the Napa crank
sensor.
I never got any codes at all either.
2 ways to find out replace it with OEM or have dealer put DRB scan tool on truck to find out.
Good luck.

Dave

 

Call the toll free number on the website above and give them the last 9 of
your vin and they will get the exact part for your truck.
Bad crank or cam sensor can do all kinds of crazy stuff.
Like I said it took lots of testing to find out it was the Napa crank
sensor.
I never got any codes at all either.
2 ways to find out replace it with OEM or have dealer put DRB scan tool on truck to find out.
Good luck.

Dave

 

Ok, thanks again. My truck also has no codes present. My scanner also has an emissions readiness tester on it and it is giving me a green light saying all is well? But I still have the mysterious shutdown issue and cold miss.