I changed the oil, oil filter, and fuel filter this weekend for the first time on the F250. Changed the t-stat too and hooked up a bluetooth transmitter to the OBDII port for the Torque Pro gauge app. 1996 7.3L powerstroke diesel with 230k miles for those just joining the show. This morning it stalled repeatedly trying to drive it to work. Since it ran fine before I did the work, I'm thinking I did something to it. Specifically, I'm wondering about repriming the fuel system after the filter change - which I did not do.

Details of the behavior -

Saturday I did the work and then moved the truck down the driveway and back but didn't really drive it. I did let it idle for a while (8-10min?) It seemed fine.

This morning was cold (28F) but we had a couple mornings last week that were about the same and the truck ran fine. Last week I'd plug the block heater in an hour before I'd crank it, but this morning I did not. It took a couple tries to start (seemed cold, duh) but once fired it seemed to idle okay and started to smooth out. I hopped out and went into the shop to find an ice scraper to cleat the windshield, figured I'd let the truck warm up a little. While I'm in the shop about a minute later I hear it shut off. No stumble, just off like you turned off the key.

I walk back out and crank the truck. Cranks right up. I start scraping window. Truck shuts off half way through. I finish scraping and crank her up, starts fine, idles fine. I rev the engine up, get the RPMS up to about 2k, hold them a bit. Seems fine. I'm thinking at this point that maybe I'm having a voltage issue since the truck's cold and the alternator doesn't start charging till I've driven to the end of the street usually. I drop it in gear and head out. I make it to the stop sign and it dies again. Alternator still isn't holding solid, but was up to mid gauge when it shut down. I decide to get it back to the house. It stalls three times in the 100 yards back, and a couple times I can hear the rpms drop for a second but not actually shut down. Halfway down the street I unplugged the OBDII transmitter, thinking it might be freaking out the PCM. No change. Every time it's like you turned the key off. No stumble, just off.

Once in the drive way it stalls at the one narrow point where I can't get past it and for once, won't re start. Engine spins strong, just won't fire. I sit for a minute trying to figure out how I'm going to push this beast out of the way by my onesy so I can get another car out of the drive to go to work. After a couple tries it fires up and backs out of the way, running fine.

So..It was running fine last week, I worked on it, now it doesn't run. Logic says it's something I did or affected. Probably. First thing I can think of - I didn't reprime the fuel bowl. It was about half full when I put the new filter in, I did let the truck idle a while in the shop and moved it around with no problem. Am I suddenly just sucking air bubbles? Seems like it would stumble or something, or would have worked it's way out after a few minutes, but...?

Other possible issues -

as mentioned, alternator charging is flaky, but it had enough power to spin hard every time. Don't think that's to blame.

Ignition switch is loose, you can pull the key out and the truck still runs, rattling it around makes the door chime come and go even in the lock position. Didn't try wiggling it while running.

I haven't changed the CPS, but I have a new one to go in. Could the cold affect it that way? Or is the CPS one of those things that pops like a light bulb, not a come and go issue?

Other ideas? What do I need to test? If it were a gas motor I'd be looking at ignition system from the symptoms, but with a diesel...I'm not sure what to check.

 

After installing electric fuel I had the problem where the tuck would cut out and stall sometimes. Since I just installed e-fuel I blamed it however the problem was CPS. So yes, sometimes they just go bad, especially if it is original.

The original CPS is black in color with a flat end. You will need to remove it to tell. If that is the one you have it needs replaced anyway. Make sure the replacement is the dark gray with purple o-ring, available from Ford or International.

 

I agree its likely something that changed since you touched it.

Basic questions:

Oil full...14 qts or so and reads full on the stick?
Check fuel pressure at shrader valve

Bowl was primed after a few seconds of the motor running... that is if you pump is good and was not already failing. Verify this with your gauge.

Next I'd think it was a simple electrical connection at your batteries, or a plug that was bumped during the oil change. Check your icp and and IPR plugs and clean them.

Regarding charging. It needs 10.5, to be dying due to voltage your truck would likely not crank over. Its always worth throwing a multimeter on it and standing there till it dies since its doing it quite often,

Yes a CPS can crap out at any moment.

 

Okay...Oil level 's pretty close. I've got 14 quarts in it, including filling up the new oil filter before installation. It's on the dipstick but I was going to drive it a few miles to work and then recheck, figured I'd have to add a little but not much.

What should the fuel pressure be?

What are ICP and IPR plugs, and where would I find them?

Last time I checked it at idle and showing low on the in-dash volt meter I had a solid 12.5 From the cranking behavior I doubt seriously it's low. I've run a gas motor until the battery died and it din't act like this, but I don't have any experience with diesels. Still, my gut says that's not the issue.

 

Wasn't trying to be rude, but you would be surprised how many guys put 7 -8 qts in and then have this issue.

Fuel pressure should be around 55 at idle. It will pulsate your gauge as its not linear like a electric pump.

 

No offense taken! Gotta start with the basics.

Excellent reference image, thanks. Going to save that one for future reference.

So what does IPR stand for?

 

Injector pressure regulator...you can think of it as a control valve kinda that works with the ICP and PCM.

 

Short answer - pulled the old CPS and slapped the new one in when I got home since that was an easy place to start and I was planning on changing it anyway. Truck runs great.

The "old" sensor wasn't that old - and also wasn't a Ford part. The PO said something about having to replace another non-ford sensor that a shop had installed with a real Ford part recently. I'd bet this was done about the same time. The entire glow plug system was redone in Jan '15 according to the receipt in the glovebox.

looks like i need to order another spare

Thanks for your help guys.

 

Great to hear! Sure is nice when its easy. Do they have the type of glow plugs that were used during the repair this past year? If they are autolites get them out of there now.

 

I don't think it listed a part type on the ticket but I'll check. What's the problem with the autolites? And what brand do you recommend?

 

The autolites swell inside the head causing the electrode to stay in the head. Stick with motorcraft

 

Motorcraft ZD-11s or Berus, I have removed a ton of Bosch plugs too that looked just fine as well. Stick to OE