Hi I just recently got my son a project truck a 1991 F350 Crew Cab 8ft bed 7.3 4x4. It has a 7.3 IDI with a Banks Turbo and the guy that traded us for it drove it up here two hours so I know it at least starts and runs. He said it needed injectors and we had to start it with starting fluid so we put it in the shop and changed the plugs. Well six of them as the last two on the drivers side were a pain to change with the turbo box on top. Well after we got six done when we tried to start it it began leaking out what looked to be the starter. of course that cant be right so I began to further investigate and it is fuel running out of somewhere down the back of the motor and onto the starter and on to the floor. How could changing glow plugs do that? We then put it in the barn and when we got it back out 2 days later to investigate the fuel leak it would not start even with starting fluid so we pushed it into the shop and saw a spark from the negative side of the passenger side battery. when we held that cable so it made good contact she fired right up. So we cleaned and replaced the battery connectors and cables tested the glow plug relay to see that there is power flowig out of the relay and all it does is crank now an wont start. the fuel leak is still there and I can see the lines in between the injectors are wet on 4 of them as well as wet on the bottom part of the plastic thing that snaps on top of the injector. Could I just be leaking fuel and sucking air? It did start after sitting but only ran for a few seconds and it sounds like it amost starts to run but just cant fire up. I am thinking of first taking out the Autolite glow plugs and replacing with Motorcraft then removing the turbo air box so I can get to all of them and test that they all get 12 volts and looking for the fuel leak. I am also thinking I will get an injector kit and replace the o-rings and fuel lins between each injector but this is my frst diesel so I am looking for some advice as what else to do or look at. I dont want to go to the shop just yet my kid is only 14 and we want to do as much as we can together so any help or advice will be appreciated.
Steve

 

Sorry I said injectors in my original post but meant glow plugs

 

First things first: Paragraphs. It makes posts much easier to read. That said, being the truck is 21 years old, replacing the fuel lines and injectors wouldn't be a bad idea, along with the fuel filter. Diesel engines need to have a sealed fuel system, meaning no air leaks at all. Clean everything off with engine degreaser and then try to track leaks, it will make your life so much easier.

Another thing to keep in mind, two strong batteries are needed to get a diesel to start. If one is weak or they're different ages it can cause problems. There is a separate IDI forum farther down that may be of assistance.

PS- NEVER use starting fluid on a diesel unless the glow plugs are disabled. It can create a very dangerous situation. I go by the rule to never use starting fluid on a diesel period.

 

Thank you I will remember to write in paragraphs. I just checked youtube for some videos on checking the glow plug relay and when i checked mine I did not have 12 volts on the other big terminal.

I had it on the small terminal at the top but I think that was just the signal wire from the ignition. So am I right to think that if I did not have 12 volts on the other big terminal that my relay is bad since I had it from the battery and the ignition was lighting it up?

 

In it's simplest explanation, a relay uses low current to control high current. So if the relay is energized and there is no voltage on the load side of the relay, it's safe to assume it's bad. I'm not exactly sure how the glowplug system works on these trucks, I'm assuming there is some sort of timer involved.

 

Sounds like a bad controller to me. Also sounds like your return lines are leaking. Under the plastic caps are 2 o-rings, you can change those and see if the leaks clear up. They do make kits that include new lines,caps,and o-rings.

 

yeah,the guys here have you pointed in the right direction.the return lines cannot be disturbed.it would be very difficult to replace glow plugs and not bump the caps,and brake the o-ring seal.
search these on amazon:
Delphi 7135-276
(toss the o-rings aside in that kit)
vition #111 (you need 16)

no need for the shop.you and your boy can handle it.
instructions:
https://www.ford-trucks.com/forums/1...tructions.html


here is how to test the '87-94 glow plug system:
https://www.ford-trucks.com/forums/1...low-plugs.html

 

You guys are falling down on the job, lol. Where's the warning for using Autolite glow plugs? Yes, definitely pull them and put in Motorcraft units.

Mike

 

that warning is down in the pre powerstroke forum.