So I have a '94 F350 7.3 IDI Turbo. I went to replace the glow plugs one day and while I was in there decided to do the return lines... First of all I cannot for the life of me bleed this truck, I think. I tried all the tricks I have read about on here, I even got some smoke and a sputter. I disconnected my glow plug relay while I tried to bleed it. I figured with the block heater plugged in for a day, it might be warm enough to fire, no luck. I reconnected to relay to see if that would help, and now my wait to start light doesn't even come on. Is the relay shot? I think I may have blown it out by accident(dropped a wrench). How do I test it? How do I make this truck run?? Also, my batteries are on the way out and don't have the juice for a lot of crank time, I have to charge them after every attempt.. Help!!

Thanks guys!

 

The best way I know to help is to add an electric fuel pump. This is my installation. You can run it for 20-30 minutes and it should have purged the air out of the system.




E8012S from AdvanceAutoParts, $41.99. It will supply all the fuel you need and you could leave it in place forever as long as you hook up an Oil pressure safety switch to shut it off in case of a mishap. You can leave the E8012S in place and use it as an auxiliary pump. The OLD Mech Pump will push the fuel through the EP. Summit Racing SUM-G1438 - Summit Racing® Oil Pressure Safety Switch - Overview - SummitRacing.com $16.95 + S&H

PS. I don't have the safety switch since I only use it when I have a fuel event.

I've read on here that if the engine is above 122*F the GPs won't come on. If the engine sputters, it sounds as though air in the system is your problem. Good luck.
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Thanks for that, but my glow plug WTS light just stopped coming on, why is this? Is is possible I shorted the relay out or is there another reason? How do I test this relay, don't wanna spend the money if I don't have to??

Steve

 

First watch your alt guage and see if your plugs are working, it could be just the light.
You can also read the stickie at the top of the page, and come back with anything you need help with, or don't understand.

 

It sounds like your batteries were 'on the way out' last year , thats where I would start spending money.
nate

 

Yeah, I had the same thought about that... So before I go buying and testing things, if I decide to replace my glow plug relay, can I use the relay off the 86 F350? My truck again is a '94 7.3l IDI Turbo. Also, what is this sticky note you refer to, on what page? Sorry I'm unfamiliar.. Thanks star, always appreciated

Steve

 

The controllers changed between 86 and 87, so no, unless you want to do some re-wiring.

At the top of the thread list here: Pre-Power Stroke Diesel (7.3L IDI & 6.9L)

-Enjoy
fh : )_~

 

Ok, so now I'm confused... I read up in the sticky forum, and it said that for my truck I can take a glow plug relay off an 86 F350 and pop it on top of my controller. I'm not looking to replace the whole unit, just the relay on top. Do I still need to re-wire stuff or am I just lost? Do I need to buy the whole unit if it is bad?

 

I'll have to go read through the sticky to see where thats stated, the 86 and 94 have totally different controllers and relays and are not inter mixable.

You can swap the complete systems with wiring modifications, but not individual components.

If I am incorrect someone will squash (correct) me.

-Enjoy
fh : )_~

 

The actual relay on the 87 thru 94 controller relay is exactly the same relay.

So yes you can buy a relay for an 86 diesel, then change out the relay on the 94 controller.



Two bolts mount the relay onto the controller.

Then unhook the connections on all four posts, remove the relay and do the reverse to install the new one.

Word of caution.

A starter relay looks just like a glow plug relay.
But they are electrically different.

When you pick up the new relay, look by the small terminals for a small S and I molded into the plastic on top of the relay.
If you see the S and I, they gave you a starter relay, not a glow plug relay.

86 glow plug relay, about 25 dollars.

93 glow plug relay and controller, about 125 dollars.

When I go for 94 IDI turbo parts, I say 93 IDI turbo.

94 had the,
7.3 NA IDI
7.3 IDI turbo
7.3 Power Stroke

And the parts man will always give you parts for the Power Stroke, not the IDI if you say 94 for a year.

Caution, when you unhook the wires, the battery wires are always hot with battery voltage.
Unhook both batteries before working on the glow plug relay.

 

Confusing ... I assume you mean the 84-94 Relay is the same, thus all IDI's use the same relay???

-Enjoy
fh : )_~

 

The relay is the same one, 1983 thru 1994.

Where it is located and how it is activated is different with the 83 thru 86 and 87 thru 94 engines.

However if you ask for a glow plug relay for an 86, you get just the relay, 25 dollars.
If you ask for the relay for say a 92, then they give you the relay and controller, 125 dollars or more.

 

Understood.

Thanks for the squashing...

-Enjoy
fh : )_~

 

That's what I thought... Thanks a lot guys, now I just need to find some time to get my parts and do the work. I'll keep you posted as to how much luck I have. Thanks again guys, always appreciated!!

Steve

 

Sorry for misleading you.

-Enjoy
fh : )_~