Hello all,

I have a 2000 Ram 1500 5.2 motor that cranks but will not start. I got the truck from a friend for free and it has sat for a year. I had to replace the ignition switch as it was damaged from a theft and the subsequent damage also fried the ECM which I replaced as well. I tried to start it and it cranks but will not fire up. So far I tested the fuel system and the pump is fine and the fuel pressure is 45 psi which is ok as well. If I spray the intake with starting fluid, it will start for about a second or two then cut off. I know it is getting fuel as I said before by the tests I've run. I put the new ECM in it today. I took my scan tool to it and got 4 codes P0123,(throttle position sensor) P0118 (coolant sensor) P0113 (intake air temp sensor) and p1492 (I think battery ambient temp sensor) I am new to Dodge trucks never owned one until now. My question is obviously all need to be remedied, but which ones could be a cause of a no start as I want to start there. It may be an obvious question, but I had to ask as vehicles today are so overly technical in my opinion that maybe something like a coolant sensor would cause it. Ya never know. Any help would be appreciated. Oh, and yes, I did siphon out the old gas and put fresh fuel in it today.

 

Given that all of those codes are for sensors that get power from the 5 volt feed from the PCM, I would start there. Make sure each and everyone one sees five volts with ignition on.

 

Thanks I will try that first before anything. I will post the results probably Friday, my truck is in my driveway and we're expecting rain tomorrow in my neck of the woods so I probably won;'t get to it Thursday.

 

Okay, it hadn't rained yet, so I tested the throttle position sensor and the MAP sensor for voltage and they are a both getting the required 5 volts. It started raining after that so I'm calling it a day, but I'm guessing the other two are getting 5 volts based on my results of the ones tested. I guess I will test the sensor itself to see if they are in fact good. Shot some more starting fluid down her for some giggles and wishful thinking and it fired up for about one second and shut off just like yesterday. As I said before, and I correct myself the truck has sat for a year and some months after the theft without ever seriously being worked on, so I'm wondering because sitting for long periods of time can do stuff to vehicles, maybe all the sensors may be actually bad. The sensors are not expensive, the most expensive one is about 35 bucks, but I don't want to be a parts changer because that may not work and even if it does you throw away cash for stuff you don't need. Want to pinpoint the issue. Any suggestions out there?

 

Don't just change the sensors unless you are SURE they are bad. These trucks tend to be rather picky about which sensors they will play with, and some of the aftermarket brands cause more issues than they solve.

Do you have a scanner that can read live data? Think I would also be tempted to disconnect the fuel line, and run some into a container, and see what the water content is like.

 

Yeah, I'm gonna test the sensors before I pull the trigger on replacement for sure. I hadn't thought of pulling the fuel line but I think I will do that this week. I son'r have a live scanner, just an DTC scanner.

 

Maybe needs a crank sensor. Mopar preferably.