93 F250 7.3 rough idle and hard start?

[30-30]

Hey y'all, a little concerned about my truck. It's a 5 hour drive to the ranch next weekend and I don't want to risk engine trouble.

Truck seems to be idling rough. (7.3 IDI non-turbo) Not any noticable smoke, and it seems to run and drive just fine. The whole truck just shakes/rattles at idle. The top of the passenger seat is the most noticable, it looks like a massage chair. You can also sometimes hear the door panels rattling. Any thoughts? I had a new injector pump installed about a year ago and it hasn't seemed quite the same since, but it has been getting worse in the last few weeks. I'm thinking maybe injector pump timing? Or maybe dirty/worn out injectors (although I use injector cleaner in every other tank).

Not sure if it's connected, but she seems a little harder to start cold too. I know it's getting colder, but I put in new glow plugs, starter, and batteries a little over a year ago. (maybe 10k miles) Takes about 5 seconds of cranking at 50-60 degrees. Maybe glow plug relay? I've heard these truck like to eat them.

Thanks.

[kfd82]

First thing to try is change the fuel filter.
Might be as simple as that.


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[30-30]

First thing to try is change the fuel filter.
Might be as simple as that.


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Did that about 3 months/5k miles ago, wouldn't have mucked up that quickly would it?

[kfd82]

Could have if you got some bad diesel.

Also might try dumping a 20oz bottle of two-stroke outboard oil in with your next fill up.

This new low sulfer diesel is hard on older motors. I know when i put it in my truck it seems to run smoother.


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[kfd82]

Start with the two-stroke oil. About $2.50
If that doesn't work try changing the fuel filter. About $10

If that doesn't work .... Ask advice from someone else.
But you are only out about $12.50.


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[JDL]

Sounds like injector issues to me

[Buckshot-73]

Sounds like injector issues to me

X-2.

[DarrellS]

X-2.

X3

[game stalker]

my truck did the same thing its a 94 7.3 got worse over time. turned out to be injectors

[brushtrooper]

Fuel filter change would be the 1st thing. If still rough, check the jumper lines from injector to injector....they get old and brittle. Have you checked the intake for visible fuel leaks @ each injector? Mine was rough running at idle and on road fine...turned out it was some old/deteriated O rings on a couple injectors...replaced the O rings on all injectors and put new jumper lines on and running strong now for about a year. Another good website to checkout is http://www.oilburners.net/forums/forumdisplay.php?f=34

[Texasm1976]

If you change the fuel filter fill it with transmission fluid besides diesel. It may smoke a little at first but cleans injectors.

[30-30]

Decided to bring this one back up to the top.

The local ford dealer quoted me $1700 to drop both fuel tanks and replace both sending units. Said that everything was tested and it was determined air intrusion in or around the sending units was causing the rough idle.

$1700 sounds pretty ridiculous. Is this the going rate for the job? Should I bite the bullet, or look elsewhere for a diesel tech?

Honestly doubtful that this will fix my problem...

[Toolman]

I would check the o rings and plastic fuel delivery cups on the injectors. The easiest way to find witch cylinder is missing is to loosen each fuel line to the injectors one at a time. You will feel it miss with each loosened fuel line. If you loosen one and it doesnt change. Start with that cylinder. You can check the glow plug relay with a test light. Put in the output side and watch how long the test light stays on. If ic cycles quick I would replace the relay. Very easy to do.