Ok guys I'm having trouble fixing my old truck. I'll start at the beginning. I have an 01 Dodge Ram 5.2. The truck sat for two years. The oil was so thick that after draining it over night it only took three quarts to fill it up. Bad news was that when I started it the oil pump only survived about ten minutes before I lost all oil pressure. I took off the oil pan and found the screen was clogged. I replaced the oil pump and pickup. Now I have a new problem. The truck sounds like it is spark knocking bad. It won't idle and it's hard to crank like it is way out of time. I've now replaced the crank sensor, cam pickup and now the timing chain. Nothing is helping. Still won't idile and if I try to drive the truck it sounds like it's way out of time.

 

P1391 Interm Loss of CMP or CKP

What brand sensor did you get? These trucks really don't like the aftermarket sensors, and you get weird behavior. Also, the connections at the PCM will sometimes get corroded, and give you weird behavior as well.


Flush the fuel system. The old gas isn't doing you any favors. Run a tank or two of premium thru it to help clean out the rest of the junk. May want to actually pull the fuel rail, and make sure you get all the crap out. (injector o-rings are pretty cheap, and it's not that bad of a job.)

Check the condition of the ignition parts, cap/rotor/wires/plugs. May not hurt to just replace them.

Pull the throttle body. Remove the IAC from it, and clean the IAC well out, really... erm... well...... Leave the battery disconnected while cleaning. (maybe put it on a charger for a few hours?)

I assume you cleaned out as much of the sludge as possible while the oil pan was down?

Once you have that done, and the truck reassembled..... Turn the key to "on", count to ten, then start the truck. You may have to feather the gas to keep it running for a few minutes...... See if it runs any better.

If it doesn't, unplug the front O2 sensor. Try again. Run better? Replace the sensor.

No? Then physically remove the sensor from the exhaust, try again. See if it runs any better.

Welcome to DF!

Moving this to second gen tech for ya.

 

The weird part trouble shooting this truck is none of the issues were there before oil pump change

 

Then probably something got bumped/jostled/crimped, and is the root of the problem. If you still have the old sensors, put 'em back in. Follow the wiring, and see what you find.

Did you jack up the motor to get the oil pan out?

 

No I didn't even need to jack up the motor. Just removed the braces from the trans to the block and then pulled the pan.

 

Check the connections at the starter motor. Maybe they got rumpled. (not that I think your problem is there.....) I wonder if some part of the harness just got pulled a bit, so you have a poor connection somewhere..... Have you looked at the connectors on the PCM? They do sometimes get corroded, and cause some strange issues.

 

I have looked everywhere. PCM connection looks fine. Im at a lose. What would make it seem out of time.

 

Distributor cap not completely secured? Plug wires in wrong order, or routed to close together?

Timing on these is purely controlled by the PCM. It uses the signal from the crank sensor to determine when to fire the coil, cam sensor determines which injector fires. It does nothing for ignition timing.

If it wasn't doing it before, then something happened with the last job. Need to go over everything that was touched when doing the pump, and swapping sensors.

It's also entirely possible that one of your 'new' sensors, was bad, right out of the box..... Not to mention that these trucks simply do not like aftermarket sensors in critical locations.... and cam and crank sensors both qualify.

 

My husband has a 2001 Dodge Truck RAM 1500 1/2 ton 4WD 5.2L SFI 8cyl (at least that's what it says on AutoZone) that is throwing a 1391 code. I understand that means there's no communication between the CAM Sensor & the Crankshaft position Sensor. We have been advised to check the wiring between the two, but to do that we need a wiring diagram. I'm here to find out where I can get a wiring diagram for him!

Any Suggestions?

 

Yup. Download the service manual from here. Wiring diagrams are in section 8W.

Welcome to DF.