Calling all '93 Ford diesel experts- problem

[Wayne M.]

I've got a F250 in that has an intermitent no start condition after the first use of the day.

Here is what I know;

-Truck is maintained,

-Fuel pressure is 5-7 # at the schrader valve on the filter at all times,

-Glow plug controller and plugs were changed, system seems to be operating normally,

-When it acts up we know that there is no fuel after the inj. pump, but there is fuel before pump and after filter,

-There is voltage at Fuel sol during run and crank,

- When it does act up, a shot ether gets it going again



This truck runs like any Ford should, and does not seem to have any other obvoius problems than this. It always starts when cold.



I am suspecting the fuel solenoid is intermitent.



What do you guys think?

 

[Power Wagon]

The most likely suspects are:



The delivery valve stop is loose (this is a pump tech problem, not a field-fixable problem) and leaks at a certain temp. Once you get the engine spinning fast enough, it pumps enough to pop the injectors and away it goes.



The "run" solenoid is sticky. This is field fixable with a new solenoid. New solenoids are roughly 80 bucks.



You can test this theory by apply 12V to the solenoid connection and it should have an audible "click" each time. If there is no "click" pull the top of the pump off (3 screws) Look at it to see if it has a large amount of magnetic crud stuck to the plunger. Also, use some jumper wires to put 12V across the terminals. At full battery voltage, the solenoid should pull in if it is a "long" version that goes all the way to the end of the top. If it is a "short" version, it should pull in after touching the arm with 12V across the terminals. In any case, it should take no more than very slight pressure to make the solenoid pull the arm in.



You can change this solenoid in the field and the new one comes with instructions on how to avoid an engine runaway - very important. Make absolutely certain when you put it back, that the arm is not bound against the linkage inside. Verify this by applying 12V to the solenoid and it should click inside the pump.

 

[Wayne M.]

Thanks, Mark! I knew you would jump in here!

Boss sez order a soleniod and we'll see what happens next week. In our operation it is sometimes hard to get what you don't have Part#'s for. We only have a factory ford catalog and the sol. is not serviced in there, only the whole pump. Looks like we might get a pump after all.

 

[Evan A. Beck]

Like Mark said, be sure to apply 12V to the soleniod when you are re-tinstalling the pump cover. If you don't, there is a good chance it will be stuck at WOT when you go to start the truck.

 

[Power Wagon]

Originally posted by Wayne M.

Thanks, Mark! I knew you would jump in here!

Boss sez order a soleniod and we'll see what happens next week. In our operation it is sometimes hard to get what you don't have Part#'s for. We only have a factory ford catalog and the sol. is not serviced in there, only the whole pump. Looks like we might get a pump after all.

Just call a Stanadyne dealer... Injection pump shop, and order the solenoid. they'll know what it is.



The part number changed just before I stopped working in a pump shop, and I never really memorized the new one, so I can't just post it for ya. . . sorry.

 

[Power Wagon]

Originally posted by Evan A. Beck

Like Mark said, be sure to apply 12V to the soleniod when you are re-tinstalling the pump cover. If you don't, there is a good chance it will be stuck at WOT when you go to start the truck.

I rebuilt hundreds, perhaps thousands of those injection pumps, never using 12V to move the solenoid. It's just a matter of slipping it in carefully. You "slide" it on from one end, and then apply 12V to see if it clicks. If it does not, it's bound. Besides, the cover won't drop down solid on the pump housing if the solenoid arm is out of place.

 

[Power Wagon]

It also occurrs to me that the 7. 3 MUST have glow plugs to start, unless it is very hot... as in, just shut off. If it's sat for more than 30 minutes, the glow plug should likely cycle. If they do not, your problem may be glow controller, not pump solenoid.



After all you did a completely no-no and got it going with ether... meaning that somehow in the starting, it did get fuel eventually... Something you need to check out.

 

[Wayne M.]

A circiut test showed that the plugs are jucing whenever the "wait to start" lamp cycle happens, which is every start. Besides, you're right in that these engines don't start unless that cycle is complete. This one is acting normally in this case.

I am really considering the delivery stop valve theory since it acts up only at certain temps- not too hot or dead cold, and the starting fluid gives it cranking speed.

The ether was used because the mechanic was stranded himself (It's our own shop rig and it's operated by either a mechanic or a mech's supervisor) and was the last straw. It proved to be a diagnosis aid.

Being a large Minucipality, we are not able to just pick up the phone and order parts. It's a top heavy, bean counting bureaucracy that dosen't always give you what you need, and that's why I said we might wind up with a complete pump since it's setting up a special purchase for a solenoid might be too easy! For example, we wanted a small port-a-power, and sent in a clipping from Northern Hydraulics, a cheap thing. A few weeks later a monstrous kit came that had everything possible except for what we asked for!



Thanks for the help Guys!

 

[Wayne M.]

UPDATE!

Hey Guys, Bet ya forgot about this problem truck! I didn't- I still gotta fix it. Here's what has happened. A complete injection pump just came in- remember what I said about working for an outfit that gets you what they think you need? It's a rebiult unit right from FoMoCo. The Stanadyme tag is gone and a IFS tag is in it's place.

I put it in today, and I must admit it wasn't that bad a job. So far it runs OK, the test will come tommorrow when it goes back into action.