7.3 Diesel Help?

[WA Nautique]

Totally not boating related, except that this is my tow vehicle, but I thought I remembered a couple of you guys being diesel mechanics and ford fans. hopefully you can help point me in the right direction?

I have an Early 99 F250 with the 7.3 Powerstroke, that seems to have an intermittent stalling problem. It only seems to affect things when I am towing the boat, or in the throttle on a hill. I have done some basic stuff to try and eliminate basic intermittent problems (new cam sensor, Hutch mod, and new fuel pump/filters) but the problem seems to re-occur when I am loaded and pulling a hill. Most of the time it has been just a hiccup, where the truck looses power, then seems to re-start itself, but I had a $750 towing bill and 3 sad kids when we were stranded on the side of the road instead of camping last year. the truck restarted without a problem when it was at the shop. I though my fuel pump might be going intermittent, so that was the first thing I replaced, and the cam sensor for good measure (yes, I now have a spare in the glove box), but I am struggling with where else to look to solve the issue. Anyone knowledgeable enough to help me ask the right questions even?

Truck is stock with 255K + for mileage.

[clrussell]

Is the fuel heater still plugged in on the bottom of the fuel filter housing?

[WA Nautique]

not sure, but I can check it tonight when I get home. Do you think fuel temp at higher flows might be affecting something?

[roadster02]

Does it crank but will not start? Does this only happen when hot? When this problem occurs and you attempt to start the truck, does the "Wait to Start" light come on like on a normal start?

[mtajpa]

Just went thru the same thing. Get a cam sensor from International and replace the 3 pin harness/pigtail.

[clrussell]

not sure, but I can check it tonight when I get home. Do you think fuel temp at higher flows might be affecting something?

Generally when the fuel heater fails it short circuits and blows a fuse.. which will in turn make the truck not start.. probably not even related to your problem but I'd unplug it

[WA Nautique]

So most the first couple of times the "stall happened" we were rolling at speed, the engine felt like it died, then there were a couple of 'Jerks" and the truck was running again. there were a couple of times where it died, and restarted fine. my vacation stall was rolling @ 45mph up hill, started chugging, then blowing white smoke. restart was really rough, then it died. this was when I replaced the cam sensor and the fuel system filters/pump and in tank pickup.

the latest trip it happened when I was at freeway speed, then I lifted the gas and re-applied it to slow down for a police officer on the side of the road. small stumble then no issues after that.

seems to happen at random times, except I am usually going up hill to some degree.

thank you CL for the fuel heater tip.

[roadster02]

Sure sounds like Cam sensor. Go onto Ford Powerstroke forum and do some searches there.

[WA Nautique]

Roadster02, that is exactly what I thought, and with the replacement it does the same thing. I will try the Powerstroke forum as well, just never participated there before. I did try Ford truck enthusiast and got no response. Thanks for your help!

[mtajpa]

If you change the cam position sensor be sure to replace the 3wire pigtail harness. I can't stress this enough. These connectors go bad and make it seem like the sensor is bad when it is actually the harness. The was a recall on these sensors a while back and it also related to a dissimilar metals issue between the non motocraft/international replacement sensors. Search for Dieselorings.com for some good info.
See link. http://www.dieselorings.com/1994-199...bes-parts.html

[nate b]

Had similar issue. Mine would start once it cooled down. My issue was a bad coil on the injection pressure regulator that's on the HPOP. Replaced the cam sensor thinking it fixed it, it didn't. Found this video, while it wouldn't start did some trouble shooting by blowing air on this coil and it would fire right up.

https://www.youtube.com/watch?v=Cw1blF6WDA8

Hope this helps.

[trunderw]

I had this with my old one. The cps is cheap (like ten bucks) so I'd give that a shot first. I had one of those go bad twice...second time I bought the "updated" model.
Your problem sounds like the final problem I had before I sold out though: There was a short in a wire going through the firewall. It manifested erratically like water in the fuel or a bad cps (which I'd been through). I couldn't make it happen, then one day after bucking and shuttering it shut off and had to be towed. The idm and pcm both shorted out. 5k and two weeks later it happened again...I sold it after that and two weeks later it happened to the guy who bought it from me. That's when they found the short. I had given the guy all the paperwork but they wouldn't honor the warranty. Anyway, hopefully it's just the cps!

[roadster02]

dieselorings is a first class business.

[Dd24skater]

Cam sensor......been there

02 Excursion 7.3

[WA Nautique]

Good info guys! I have done the grey cam sensor, but not the harness I'll see if I can find a replacement and give that a shot. I'll do some more reading on the blue cam sensor and the IPR valve as well, I wasn't aware that there was a 3rd updated cam sensor. If it solves the issue, I am happy to learn from others experiences along the way. hopefully I don't have a firewall short!!! holy cow batman. That's a bummer.