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Discussion Starter · #1 ·
Hello everyone
So long story about this one...
Neighbor in Alaska had this 95 F-350 with the 7.3 and the 5 speed sitting in the yard since 09'
was able to get it started with some new fuel, 911 and batteries! only thing I needed to replace was the water separator and starter solenoid.
So I get it back to the shop under its own power, blowing white smoke everywhere and drained the bowl quite a bit to purge the lines of water..
today I go out to start it and let it run for several hours just to get the additive through every nook and cranny.
White smoke and I mean THICK white smoke bellow out from the engine compartment, come to find out its coming from what looks like the fuel rail next to the separator...
Finally get it to start, this thing is very hard to start, every time. Have had to charge the batteries twice so far.
As I let it warm up it dies.
will turn over and sounds like it wants to start.. the onboard computer display shows error and the wait to start dummy light is no longer coming on...
Now the onboard computer is from Ford with Power, Charge and RPM buttons, don't know if it is an actual computer system or just an attachment.
any help would be great! I think it could be the glow plugs? maybe?
 

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If the onboard computer you are referring to is actually in the the cab, it sounds like the Auxiliary Powertrain Control Module (APCM) which is also known as an Auxiliary Idle Control (AIC) module. It lets you control the idle speed for charging or running a Power Takeoff Unit, etc. The actual Powertrain Control Module (PCM) is in the engine compartment low on the driver's side firewall near the inner fender. If your Wait-To-Start light is not coming on, your fuel heater could have shorted. Check Underhood Fuse #22 to see if it's blown (preferably with a meter).

To check the injector/glowplug wiring: From each valvecover gasket connection's outermost pins (2 per connector) to ground you should get 0.1 to 2 ohms (indicates good plug and wiring). From each valvecover gasket connection's center pin to each immediately adjacent pin, you should get around 3 ohms (indicates good injector solenoid and wiring). You should not get any continuity from any of the outer pins to the 3 inner pins (indicates no shorts between injector and glowplug wiring). You should also get 0 to 1 ohms from each of the external harness connectors outer pins back to the Glowplug Relay's large terminal on the GP side (indicates good wiring from external connections back to the relay).

To check the glowplug relay (GPR), measure the voltage drop across the GPR's large terminals. While the GPR is active (up to 1.5 to 2 minutes after the key is turned to Wait-to-Start) put your meter leads on the large terminals (one lead on one large terminal and the other lead on the other large terminal). This measures how much voltage is being "lost" across the relay. A reading of 0.3V or more indicates a bad relay. Also, check the relay’s control wires (smaller wires) disconnected from the relay for battery voltage at the Red/Light Green striped wire and ground at the Purple/Orange striped wire (check both when the key is turned to Wait-to-Start).

Cheers!
 
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Discussion Starter · #3 ·
Thank you for your detailed explanation Patrick!
All fuses are tested and ok, you are correct in assuming about the aux pcm as well!
The aux pcm states error when key is turned to on position at boot up...
When testing the glow plug relay I was pulling 13.75 volts when key was in off position and 13.16 volts and dropping when key was in on position.
From the way you explained things I will start with replacing the relay, even though jumping it did not do anything.
 

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Jumping the large posts on the relay should have made some good sparks -- Else the glow plugs are bad or the harness going to them (read UVCH)
 

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Discussion Starter · #7 ·
So I may have found the issue? down on the lower end drivers side of the fuel system is a very damaged wire connection and a bad wire.. Is there a way to pull this connection off and repair? or is it a fixed connection?
Automotive tire Motor vehicle Automotive design Scrap Gas

Motor vehicle Automotive tire Automotive wheel system Gas Auto part

Light Automotive fuel system Motor vehicle Automotive tire Gas
 

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Looks like that is to your fuel bowl heater. Unless you live in extremely cold climate just cap it.
 

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I would think that AK would be one of the places a fuel heater would be handy in the winter
Need to be sure that exposed wire is not shorting on anything -- maybe slip a piece of vacuum hose over it for a temp fix until you find all the problems

Testing the voltage on the glow plug relay -- when the relay is on, just after you turn the key -- there should be voltage on both large posts -- I would expect to see about 11.5 volts

Would also be good to get a fuel pressure reading, there is a schrader valve on the fuel regulator
There are 2 filters in the tank that may be plugged, basically running you out of fuel to the engine
Can take the filter cap off and key on to see how quickly the fuel fills the bowl
 

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Just a clarification on the relay test: Make sure if you are going to measure voltage from one large terminal to ground and then doing the same on the other large terminal to ground. Subtracting the two readings will also give you the voltage drop. Just make sure that both of the measurements are taken when the plugs are active, otherwise you may end up relacing a good GPR. Cheers!
 
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Discussion Starter · #12 ·
Thank you all for your explanations.
the GPR is bad along with a MAXI Fuse #22 that my reader incorrectly read....
next week I will be getting the new GPR and a new fuel heater.
thank you again for all of your input.
 

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If you are going to replace the fuel heater, get the SuperDuty style: 1999 - 2003 Ford Fuel Bowl Heater Element (dieselorings.com)
It can be retrofitted on our trucks. Note that the plastic filter standpipe is LEFTHAND threaded. Use a 7/8" crows-foot wrench to remove it. The original style fuel heaters fail too often. Cheers!
 
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