I'm stumped! I recently had the codes read on my 2000 e350 PSD. I've done all the corrective work, (changed passenger uvch, new cps, new exhaust back pressure sensor and tube.) I swapped out the IDM shortly before I installed the ebps and it ran fairly well, just a little chug or hiccup upon first starting. It got a bit worse and that's when I replaced the ebps and tube. As I was changing out the ebps, I had to drop the lower alternator to get to it. Upon inspection of the alternator, I noticed that the hot wire going to it had been arcing on the connection post and had burned up a couple of the threads on the post. Took the alternator to autozone and it checked good. My "fix" was to put a barrel nut on the post so that it would tighten up over the damaged threads. Seemed to work fine. NOW the dilemma: When I go to start the van, the battery voltage drops drastically when the fuel pump kicks in. It will rise back up on the guage after it cycles, but just clicks when I try to engage the starter. It WILL start from a jump, but runs rougher than a cob! Also the batteries seem strong when I turn the headlamps on, windshield wipers, etc. Both batteries test out at around 12.5. Any suggestions from you PSD gurus? Thanks guys!

 

How old are your batteries? Have you had them load tested? and are all your connections clean and tight?

 

Both are around a year and a half. Haven't been load tested, but were cranking fine before I replaced the ebps. And yes, I cleaned all 4 posts and cable ends.

 

Also cleaned all 4 posts and cable ends.

 

That is pretty weird! Seems like you have something drawing a Lot of current...possibly the starter cable, starter itself...? Good luck finding it.

 

Thanks lartross, I need it. A friend suggested checking for a short in the fuel pump wiring or the fuel pump itself. Guess that's where I go next.

 

hook a volt meter to your batteries and turn switch on, fuel pump should be a minimal drop, fuel pump and glow plugs about 2 volts, watch voltage until both have finished cycling. than try to start if voltage drops way off ie 5 of 6 volts it is most likely a battery problem! which is my guess as you stated it will start when jumped.
you can also repeat the procedure one battery at a time, but if you change one change them both. as for the age of batteries, that doesn't matter too much they can be junk at any age.

 

also a battery with an internal open between plates will show 12 volts with no load, this is why the volt meter on the battery when trying to start. kind of replaces a load test.

 

one last thought, did you have the key on or on accy. while working on it and severely drain the batteries? if that is the case there is no quick charging them, they are big batteries and there are 2 of them.
starting these trucks with low voltage can do some weird things. one time on my '97 I had a battery issue and only the left bank of cylinders would fire, it runs really rough on 4 cylinders.

 

If it was the fuel pump (which comes on at the same time as the Glow Plug Relay), that much current would burn up the wires. The GPR, on the other hand, can easily take the voltage down - and it would time out at about the same time as the fuel pump this time of year.

This sure sounds like a weak battery, or a combination of something shorting and the GPR activating.

 

Another thought-if the fuel pump had a problem which was the cause of the voltage drop, you would blow a fuse immediately.

Rich and the others are on to something here with the batteries-get them fully charged, then try. If no go, then have the batteries checked, especially if the voltage drops off on start-that is a great idea to clip a meter to the batteries during the start sequence.

 

Hey guys, thanks for all the directional arrows! Charged both batteries and they both read over 13 volts after being charged. Re-installed both of them this morning. Since I didn't have a second set of hands, the only thing I was able to check was the top battery after turning the key on. Fuel pump cycled and sounded stronger, about 20 second, glow plug light came on for 4-6 seconds, that seems normal. Top battery dropped less than 2 volts with the ignition in the on position (while fuel pump and gpl were cycling.) I'm able to get it to start and run (barely,) and only if I give it about half throttle. still wants to die and still runs rougher than a cob. Any other areas to try? I'll have another set of hands this evening to check the voltage with the starter engaged. Thank you all for your direction, don't really want to give this van up, it's a great tool hauler and office! LOL! (self-employed, remodeler.) Getting kinda tired of throwing money at it, it's not the easiest thing to work on, but I feel I'm probably just $100.00 away from victory! Hate that feeling! LOL!

 

Found something of interest in my under hood fuse and relay panel. The # 25 fuse (NGV Module) and #26 fuse {Generator/Voltage Regulator (Diesel Only)} are both missing. Is there a reason for that? Some kinda mod where they aren't required? I don't recall ever removing them. Both batteries have checked out fine under load. I just noticed this last night as I was bench testing the relays and fuses.