I've just rebuilt my 5.9 magnum, and when I went to start it, it appeared to be out of time. Since starting it the first time, anytime I start it now, it will run for maybe 2 minutes if it's cold, but when it warms up, it sputters and dies and has trouble starting again. I timed the cam and crank at tdc when i rebuilt it, but I also had to remove the distributor when doing the rebuild. I'm not familiar enough with distributors to know if its 180 out, and if not, how to adjust it to run well. I've not replaced the cam or crankshaft sensors, so it could be either of those given the p1391 code. Just wanted to know if anyone had any input before I replace parts? Or, if anyone knows if I've just messed up my distributor or crank sensor on install.

Note: at one point, it wouldnt start, so i unplugged the crank sensor, turned it over, then plugged it back in and it started fine and ran for about a minute.

I'm honestly at a complete loss for what to do next. Any help would be appreciated. Hope this all makes sense.

 

Pull the crank sensor and have a look at it. They are frequently victims of engine/trans R&R.

If the distributor was 180 out, it wouldn't run at all. Fuel sync might be off..... there is a process to set it 'close' in the service manual. (distributor R&R) that should at least get the engine to run halfway decent..... Need a scanner to properly set fuel sync. (and it needs to be a fairly high zoot scanner to even tell you fuel sync....)

 

Ok, good to know. What exactly would I be looking for on the crank sensor? How would I check it?

and if i get it close to the fuel sync, would it be driveable enough to get it to a mechanic to set it properly?

 

Crank sensor is just a hall affect sensor. So, just make sure it is in good condition visibly, nothing is bent, and the wires didn't get trapped between engine and trans.

 

#1 cylinder at TDC ON THE COMPRESSION STROKE it should look like this..

 

I replaced the crank sensor, and it got rid of the engine code. Now my only issue is that it won't idle. If I give it gas and keep the pedal pushed so that it sitsaround 800 rpms, it runs great. But the instant i let off the pedal it dies. Any thoughts now?

 

thanks, I appreciate it! Next step is to check this^ again

 

Yeah, check your fuel sync again... but, I don't think that's it..... Have you cleaned the throttle body? If not, wouldn't be a bad idea... if you have, do this: (or, do this after cleaning it...) Disconnect battery, turn on headlights, count to 5, turn off headlights (resets computer) reconnect battery, turn ignition "On", do not start it yet, count to ten, don't touch ANYTHING while counting, (lets pcm relearn zero values for various sensors) start the engine. PCM should figure out idle fairly quick. If it doesn't, then you have another problem in there somewhere.

 

Sweet, will do. Thanks again! I'll update once I do this^

 

Update: the truck is running alright. It idles fine and reacts well to the pedal. However, when i drive it, or just give it gas at idle, if I let off the pedal fully, it goes down to about 500 rpm and cuts off. Also, once I come to a full stop, the oil pressure gauge drops to 0. I replaced the pump, pickup tube, sending unit, and it is ful of oil. Any guesses here? Sorry, I know this is unrelated to the original question, I just figured I'd keep it on one thread.

EDIT^ I've fixed the issue with the engine dying, however, the oil pressure issue is still present. I've checked the oil sending unit, the pump and tube are new, no leaks, etc. I can't see any real issues. 2 things I'm finding are either, I'm running oil that's a little thin (running 30 weight break in oil, so stock recommended), or... which I'm hoping isn't the case, my crank bearing clearances aren't correct. Again, any input on this would be greatly appreciated. Thanks in advance.