Hard start. Glow plugs/fuel.

[MrStretch]

Hey all.

I apologize for not being able to solve this with a forum search. I’ve got a 92 350 with n/a 7.3. that’s been hard to start. Put a new (amazon supplied) GP controller in and a set of beru glow plugs. After that the wts light only came on for a split second when I tried to start it. (Click, click, click) I also replaced a return line cap to fix a fuel leak on one injector.

So I have a GP controller that I’m not sure is working properly and on top of that I’m pretty sure that I have (or at least had) an air leak that makes it really hard to start.

My questions are assuming I’ve fixed the fuel leak do I have to bleed the air out or will running the truck remove the air without having to bleed the lines?

#2) in trying to get my glow plugs working I read up on installing a manual switch. I took a length of wire and jumped from battery positive to the terminal with the white wire that goes to the relay (?). After doing that and leaving it there for a few seconds now my wts light seems to be on permanently. Whereas before it would just click over and over. I’m hoping I didn’t f-up the relay and burn out my brand new plugs.

Anyway. Would appreciate some input from the brain trust. I’m borrowing a first gen Cummins while my truck is down which is nice but I really need to get my rig back on the road.

 

[JAKRANCH]

I just replaced half my return lines and glow plugs the other night. Granted the engine was warm but she purged the air and fired after just a few turns. I'd highly recommend doing both plugs and lines after running the truck. Haven't fiddles with the 7.3 controllers both my 6.9s run manual push button and I love them.

 

[MrStretch]

Previous owner installed a push button but it was disconnected when I got the truck. The wiring diagram I’ve seen shows it going from hot on the fender relay to the switch and then back to that relay terminal on the glow plug controller. That was why i tried to do the same thing with a wire.

I’m (obviously) not much of a mechanic. I bought the return line kit because i had an obvious leak on one injector. Since the weather sucks and I’m not much of a mechanic I just did the 1 line. Just want to get back on the road and maybe I’ll do the complete line kit this spring when the weather doesn’t suck.

Did I hose something trying to jump the GP controller? I must have done something to it to have the light stuck on. I just hope I didn’t ruin my plugs.

 

[snicklas]

If you connected +12 volts to the small white wire location on the relay, then you have blown a fuse, burned a fusesble link, or fried the new controller, or a combination of those

The controller pulls the white wire to ground to activate the relay. I’m the normal wiring configuration, one small terminal has ignition on +12 volts, the other small terminal has the white wire that is supplied a ground by the controller, or a manual bypass button; connected to ground. The 2 large terminals have the large hot lead from the starter solenoid, and the other supplies the plugs via the Z shaped resistor.

Personally, I would disconnect the high current hot from the starter solenoid, to make certain the plugs are not working and give it a little whiff of ether and get it running. Once you know it will run, we can walk you through troubleshooting the controller, or wiring up a manual bypass......

But the WTS being on constantly tells me the controller is fried. I saw a truck that had a battery reverse polarity cause the same symptoms....

Also, when cranking do you get any white smoke from the exhaust?

 

[franklin2]

Take the white wire off and tape it. Then take your jumper wire and hook it to the bare terminal where the white wire used to be. Then go over and touch the other end of the wire to the battery negative. If you hear a thunk from the relay, you are good to go. Don't leave it on there though, when you hear the thunk the glowplugs should be glowing.

Not sure you can do this by yourself, it would be better to have a helper crank the truck over while you are touching the wire to the battery negative. Touch the wire for 10 seconds, then crank it over. If it won't start, touch it for 10 seconds again and try again.

If it still won't start but you are getting a bunch of white stinky smoke out of the exhaust pipe, you have fuel and your glowplugs are still not working. If you have this sceanario write back in and we can help figure it out.

If it won't start, and you do not have white stinky smoke out of the exhaust, then you have a fuel problem. Since you have the white wire off and taped, I would do what was suggested before and give it a short shot of ether and see what happens, just to get things moving and try to get fuel to the engine.

 

[MrStretch]

I gave it the Cosby this morning but it still won’t start. I have to fix my air intrusion issue. Are those billet return line setups worth the extra money? My whole idea with this truck is to have something dead simple and reliable. The reduced connection count on the billet lines are appealing.

 

[MtnHaul]

If your plugs are not working correctly and you have air in the lines then it might take A LOT of cranking. Even with good glowplugs I have had to crank for far longer than I would have thought, but this was with the mechanical fuel pump. Although some would consider an electric pump less reliable than a mechanical I personally think it is easier and simpler to just carry a spare electric pump and make sure the pump is installed in a manner that is easy to replace on the road. I demo'd that concept on my rig and found that a pump swap took less than 20 minutes and no need to mess with gaskets or even get dirty.
The billet returns look nice but a standard kit should work just fine. I have at least 50k on my return lines and no apparent air intrusion/fuel leaks. Also it's pretty easy to keep spare return lines, caps and o-rings in the truck--they live at the bottom of my center console.

 

[MrStretch]

I plugged my truck in the other night and it fired right up in ~20 deg the next morning. I’m getting the kit from Wes to do away with my GP controller. Hopefully that gets me back on the road. I think my fuel leak is fixed for the moment and I’ll decide what to do next. Maybe nothing until it starts leaking again.

 

[franklin2]

I plugged my truck in the other night and it fired right up in ~20 deg the next morning. I’m getting the kit from Wes to do away with my GP controller. Hopefully that gets me back on the road. I think my fuel leak is fixed for the moment and I’ll decide what to do next. Maybe nothing until it starts leaking again.

There is a kit? All you need is a pushbutton switch and a piece of wire from the auto parts store?

 

[Thewespaul]

There is a kit? All you need is a pushbutton switch and a piece of wire from the auto parts store?

This is what he is talking about, it does away with all the stock setup https://www.oilburners.net/threads/glow-plug-solutions-from-classic-diesel-designs.84741/