Hard start, not fuel return[?]

vagabond0351

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Just probed everything in the system. Glow plug light comes on as intended every time relay closes. Battery voltage goes to glow plugs every time the manual switch is closed, and every time the auto controller signals. I've disconnected the auto controller from the relay for now and will put the new plugs in and just use the manual switch when my injectors and line get here from russ.

To confirm again, these trucks should generally start without glow plugs on warm days (80*F) right?

Still no bubbles/drain back in my clear lines...
 

Rdnck84_03

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I'm not sure how mine falls in with normal but if it is completely cooled down it either requires about 5sec glow time or 15ish seconds cranking time to start with temps over 100 degrees.

James
 

IDIBRONCO

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At about 95*, mine starts without glow plugs. That is if the sun's been shining on the hood. I haven't even tried to time or count how long it takes to start so anything that I'd say about that would only be a guess.
To confirm again, these trucks should generally start without glow plugs on warm days (80*F) right?
80* seems to be on the cool side for starting without glow plugs to me.
I've disconnected the auto controller from the relay for now
I don't know exactly how you've disconnected the controller, but all you have to do is unplug the plug on top of the controller and your glow plugs will work fine manually like you have it now. Just my opinion but I don't think that you have to keep checking for air bubbles in your fuel system. I think the problem has been found.
 

vagabond0351

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At about 95*, mine starts without glow plugs. That is if the sun's been shining on the hood. I haven't even tried to time or count how long it takes to start so anything that I'd say about that would only be a guess.

80* seems to be on the cool side for starting without glow plugs to me.

I don't know exactly how you've disconnected the controller, but all you have to do is unplug the plug on top of the controller and your glow plugs will work fine manually like you have it now. Just my opinion but I don't think that you have to keep checking for air bubbles in your fuel system. I think the problem has been found.

Thats exactly what I did, just pulled the pink wire off the relay solenoid.
Im a bit apprehensive about putting the new glow plugs in until I've replaced the injectors since I think I read that dribbling injectors could damage the plugs or something. I'm just paranoid at this point and I've thrown a lot of time and cash at a truck that still isnt quite right... but like you said, hopefully the problem is found
 

IDIBRONCO

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Thats exactly what I did, just pulled the pink wire off the relay solenoid.
I meant unplugging the plug off of the top of the controller, but as long as it's not getting power, then it won't hurt your glow plugs. That's where I'm paranoid about mine. I was afraid that if I left the controller plugged in, then, somehow, something may happen and send power to the controller again. Of course now that I have a 7.3 in my Blue Truck, I still use the factory wiring for the glow plugs, but I don't even have a controller so there's no chance at all that a bad controller can burn out my glow plugs. I'm actually very easy on my glow plugs too. I haven't had to replace one in at least 4 years. That's why I love manual control for glow plugs.
Im a bit apprehensive about putting the new glow plugs in until I've replaced the injectors since I think I read that dribbling injectors could damage the plugs or something. I'm just paranoid at this point and I've thrown a lot of time and cash at a truck that still isnt quite right..
This is perfectly understandable and also the right line of thinking. Yes, a leaking injector will burn the tip off of a glow plug on that cylinder. I've had it happen to me. If you want to drive your truck without glow plugs, you can plug in the block heater for a couple of hours and it will start. Once the engine's warm, you don't need glow plugs to start.
 

chillman88

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Again, my experience is with the 7.3 system....

I run my plugs for 4-5sec at 80 and it starts good. Doesn't take much but they will need a little bit of heat. If you've been running it and it's still warm you shouldn't need the plugs at all. Won't hurt to try to start it before running the plugs if you're not sure, if it won't go run the plugs.
 

m002922

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Looking forward to the concluding report on this. Your symptoms are my truck exactly . . . and I've gone through about 1/2 of what you have. I think I have 7 working glow plugs (ZD28). One is broke, bad, and completely stuck (as in have to pull the head - no getting out with any type of e-z out screw extractor). I'm going to have to live with that.

Before messing with the glow plugs it would start on glow plugs even though only about 1/2 were working. Now, after glow plugs and an electric fuel pump and bleeding the system etc. etc. - will only start with a touch of ether. Will start in an instant with ether and after warm. May be checking my glow plugs again and going to a CDD standalone manual kit. (But waiting to hear the conclusion of this first).

Thanks to the OP and all the comments.
 

vagabond0351

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Picked up motorcraft zd28 plugs from O'Reillys. They look exactly the same as the plugs the shop installed; they do not say "beru" anywhere on them. Package says made in germany

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MadMac

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And since the fuel is staying full in the clear lines on either side of the injector pump(not to mention the e-pump primes to the ip), it couldnt be an issue before that, right?

Air intrusion on the return side will not be effected by the separator - so the separator isn’t an issue if your problem continues… fwiw, my separator came apart internally - but did not leak fuel or water, just air… btw - there are photos of my R45 install somewhere in my previous posts with Austin86250.

As to there being a problem upstream the Separator - seems unlikely since the separator is the highest point in the system and I would expect any air to find its way to the input or output side - so you’d see the bubbles… that said… you could have a marginal sender, tho I’d expect some different symptoms.
 
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Black dawg

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Picked up motorcraft zd28 plugs from O'Reillys. They look exactly the same as the plugs the shop installed; they do not say "beru" anywhere on them. Package says made in germany

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I do know over the years there have been variations of the coloring/lettering on the zd9 plug (7.3) so maybe they have changed something, or maybe someone else makes them for beru? Seems odd to me that the body and the lettering would look different than the current zd9?
 

IDIBRONCO

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As to there being a problem upstream the Separator - seems unlikely since the separator is the highest point in the system and I would expect any air to find its way to the input or output side - so you’d see the bubbles…
Except that he has a 1986 and the stock water separator is under the brake booster.
 

Old Goat

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You made me go out and look at my 86.
Mine is long gone, but the 2 studs and nuts are there where it was mounted.
It was mounted close to the Fender, to the right of the hood Hinge. And maybe 2 1/2" or so below the top of the Booster.

The Fuel come along the Frame , then up to the Filter, then back down under the engine to the Lift pump and then up to the Filter on the engine.

So the Separator really is/was the high point.


Goat
 

MadMac

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Except that he has a 1986 and the stock water separator is under the brake booster.
OH JEEZE. Under. Thank you @IDIBRONCO for the correction. I’ll have to go look at the illustrations… wondering what was put in its place.
 
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