Help-Diesel ?

Got 03 250 4x4 7.3
Went walmart this morning about 2 mils up the road, left the to come home and truck started missing bad and I turned in another parking lot
got half way in and it cut off. Waited at 20mins. and it started back up and got it in a space and let run, run smooth for about 5-10 mins
and started to miss again so I cut it off.

What will make it do this???

cel on when it acts up? sounds like inj harness working loose under the valve cover.

What is ( cel ).....when it first stopped I wiggled them around but didn't try to restart it for about 15-20 mins. but then it started right up,
Its about 2 mils. from the house so I just pulled in a parking spot and waited to see how long it would run, ran about 5-10mins. and started
to miss again so I cut it off. My brother ways there then so I locked it up and came home. I'm going back in the morning and if it starts I'll try and make it home.

Check engine light


Boo Boo

Check engine light come's on but go's out when it starts up, it will start up and run a few mins. but miss's bad.
So is that the  inj harness working loose under the valve cover. I'm going to pull the cover's and do the 50 cent mod.

sounds like it, a scan tool would help confirm though.

richter69 wrote:sounds like it, a scan tool would help confirm though.

Whats a good scan tool to get?

My brother used to have V10 and needed the coil packs and none of the parts store scanners would read it,
had to take to the Dealer and get them to read it.

Snap On. Best to borrow, or know someone who has one.

What should the alt. be charging on this?. 03 -7.3.....Mine is between 13.5 & 14.1 with both battery's fully charged. No accessory's on.
Is that high or OK ?

That is the correct voltage range for your truck.

OK, Lets do this again..2003 7.3
Pulled the valve covers and had the 50cfix already, cut down quarter in the clip to hold it tite but the passenger side was a little lose,
had about 3/16 gap so I put washers in it that was a a little thicker and they are real tite. Started up and ran smoother but still had a little miss,
after abut 10mins. was missing worst..Put a thermo temp gauge on the ex. and this what it reads. after 10mins of running.
taken on the ex. right at head.
Front of motor

Driver side......pass-side

152 =F            144
201                 149
219                 176
224                 215                    
                     
Cut it off and started back up and its like running on 3-4 cl.

DON'T know if this has anything to do with it but the day before it started this, went out to start it up and the battery's
where dead? so charged them all day to full and next day went to the store about 2mil. and thats when it started this sh*t.
Battery's will still go down in 2 days.? just sitting? can't find the short yet.

any more idea's? what to check, dont know anyone with scaner and the ford dealer herre dont know sh*t, they'll tell ya you need a
motor if it needs a spark plug.

Replace the alternator, its dead shorted and draining the batteries. Replace the batteries they are damaged from repeated drains and then rapid recharge, then drive. If problem continues after electrical system corrections, I would look at the fuel pump as suspect.

Keith I know the Gurus will say I am wrong but mine did this exact same thing in Wisc. and after $1500 I got a new electric fuel pump put on and runs great now....

I agree, years of its OK have accumulated and now its going to need a little loving on several systems. The running issue has very little to do with the electrical issue, EXCEPT modern diesel use electronic fuel injection.

OK guys replacing both tomorrow...thanks

i agree that the fuel pump is most likely the problem at the moment and replace any other fuel filters that is on the truck  

have you had the filter in the fuel tank mod done or replaced the filter?its best to eliminate that filter with the mod look it up on youtube and how to replace the fuel pump is on their as well.

long story short my 99 f250 had a fuel pump problem when I got it 3 years ago.the snap on tester showed some injectors were bad so I replaced them all and put in new glow plugs,NO help at all.so I put a fuel pressure gauge on it and found the fuel pump working good sometimes.

if someone knows what is causing the glowplug relay to blow the fuse I would like to know.

Yes did the fuel tank mod  a week before this happened.
Have done all the fuel mods.

most times the pumps work or they dont.

the screens in the tank plug up and cause issues, but its mainly under heavy load etc, never idling...... unless its restricting the pumpmbad enough and overheading it. The pump from a dealer is 560 bucks so Id make sure its bad first.

the regulator valve and spring gets worn out and wont regulate the fuel pressure correctly, imo putting a gauge on the housing and checking pressure along with the guage on the end side of the pump will tell you a lot.

just because the inj harnedd is plugged in done mean the connector dont have issues.

scan tool is gonna save a lot of time and money wasted instead of tossing parts on it.

Dont know anyone with scanner so I'll go down to the dealer and see if I can pay one of the guys to come by
after work and check it out, only 4 mils away.
Ive done away the tank screens, and have the new  regulator valve and spring, higher pressure but didnt
get around to putting it in yet.

If the connecter is bad will they drain the battery?

unhook the big wire from the alternator to see if it fixes the battery drain.

Did that last night, so I'll wait and see.

Good info here.Keith,hope you get it fixed soon.I would try one thing at a time,so you will know what the initial problem was.I have 3- 7.3's now w/o issues so im following this thread closely. The miss sounds like the harness to me.

Most parts store chains offer a free scan. They like to sell parts.  

maverick wrote:Most parts store chains offer a free scan.  They like to sell parts.  

Parts store scanners won't read ford trucks, at least they couldn't a few yrs ago.
My bother had one of the first V10 vans and they couldn't read the bad coil packs.
Took it to the dealer and they said only the ford scanners will read the trucks.
Dont know about now.
But it wont go out the yard, had to pay and get it home once thats enought.
when I do get it fixed I'm going to let it run a tank fuel out in the yard before I hit the street.  

Up date!!!!
Well after the last post went out and put fuel press. gauge on it and nothing but the pump was running.
so pulled the front line off pump and nothing, pump still running like hell. It was going bad and
finally just quit.
Just got the new pump & alt. on and is running fine as frog-hairs...

Thanks guys for your help.

Keith