Reviving a 1990 F250

[Selahdoor]

No reason not to if the plugs are good.



Yeah there's more than one way to skin this particular feline. That's how I personally would do it. Unhook the plug harness from the controller and the plugs since you need to replace it anyway.

Pull off your air filter. The controller is waaayy in the back there. It's not bad to reach but you'll be leaning in a ways. Usually under a plastic cap that's there to keep the air filter housing from accidentally lighting it on fire by shorting it out

Yep.

If I decide to leave mine where it is, I am considering cutting and shaping a better cover for that thing. Out of an old home depot bucket. From when they were a lot thicker.

 

[pastorjeep]

Take a test light from hot on battery to the glow plug tip and test them (yes ohm test is better) then put parts store bullet connectors on the wires until you replace the harness with fresh. If more than two gp's test bad she won't be happy unless the compression is perfect on that engine. In that case as was suggested a little carb cleaner in the throat and away you go. Try to video the first start.

 

[Finn]

Make sure to crank it with the throttle floored. That will make sure the IP is sending max fuel to the injectors.
(priming at idle is basically a fools errand).

No need to depress the throttle pedal during cranking. The governor on the Stanadyne pump is designed such that the pump moves to the full fuel position while cranking regardless of what your foot on the gas pedal is doing.

Think of it this way: as soon as the pump starts turning, the governor weights go to full fuel until the engine speed matches the governor setting. O foot position = 700 rpm. If the actual engine speed is below 700 rpm, like in cranking mode, the governor advances the fuel setting automatically until the set 700 rpm set point is reached.

Also, unless there is obviously coolant in the oil, it won’t hurt to start the engine prior to changing the oil. If you think the engine is in relatively good shape, it wouldn’t hurt to change it, though...your call.

 

[Thewespaul]

We’ve had this discussion before, it doesn’t affect the fuel volume by moving the throttle when cranking, but it does change the timing since the advance piston is shoving the cam ring over.

 

[Finn]

It’s been a long time, but if I remember correctly, the timing is fuel pressure / speed dependent. The pump design is such that the optimum starting calibration was developed with no pedal input. There is very little fuel pressure developed until the rpm builds after the engine fires.

No sense to reinvent the wheel, but to each his own, I guess.

 

[Thewespaul]

It’s been a long time, but if I remember correctly, the timing is fuel pressure / speed dependent. The pump design is such that the optimum starting calibration was developed with no pedal input. There is very little fuel pressure developed until the rpm builds after the engine fires.

No sense to reinvent the wheel, but to each his own, I guess.

Timing is based on two things in the db2s, hydraulic advance through transfer pressure, and mechanical advance from the light load advance arm. At cranking speed the hydraulic advance is null, but that mechanical advance still makes a difference with throttle input.

 

[nostrokes]

Nice lookin rig there.. if you just want to run it for a few without the hassle of figuring out the GP's just plug it in for a few hours and crank it over. If it's got good compression it should fire easy. Mine starts fine if with bad GP's if I do that.

I don't touch the go pedal until it smoothes out and the oil pressure is up when its extremely cold out

 

[Macrobb]

No need to depress the throttle pedal during cranking. The governor on the Stanadyne pump is designed such that the pump moves to the full fuel position while cranking regardless of what your foot on the gas pedal is doing.

Think of it this way: as soon as the pump starts turning, the governor weights go to full fuel until the engine speed matches the governor setting. O foot position = 700 rpm. If the actual engine speed is below 700 rpm, like in cranking mode, the governor advances the fuel setting automatically until the set 700 rpm set point is reached.

I know it's supposed to work that way(logically, it does, based on how the insides of the pump work).
In reality, however, I've seen a lot less fuel coming out the lines with the throttle at idle when cranking. I don't know if it's due to timing, allowing the ports to line up better, or that the metering valve doesn't always move to full fuel, but I've proven this in practice multiple times.

It may also only apply with air inside the IP; I couldn't say for certain. What I do know, however, is that bleeding of lines takes a lot less time if I keep the throttle floored when doing so, vs at idle.

I will also point out that I've seen a couple Stanadyne DB2 calibration sheets for various pumps. At the low end(cranking volume) I see "WOT" for throttle position... so perhaps there is a reason?

 

[Va_Mike]

So I just jumped in it this morning and tried to start it with and without the petal depressed. I did 15 seconds of cranking followed by about 5 min of letting the starter cool down, I did this 4 times. I could smell some exhaust but it never started. It did sound like a couple cylinders may have been trying. After that I checked in the engine bay and found fuel on the valley pan. Not sure if I spilled it when checking for fuel pressure and didn't realize or if I have a fuel leak I need to find. I cleaned the fuel up and then began checking the glow plugs. I used the test light method and all 8 tested good, i then used the ohmmeter and tested the wiring in the harness. It also tested good but the plastic covers on the connectors are all crumbling. I then started chasing wires (previous owner ran a bunch of new wires under the hood, all red) so I am trying to figure out that is powering what.

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[IDIBRONCO]

Not to mention that if the sticker is still on the driver's side sun visor, it tells you to give it some throttle when the temperature is cold.

 

[Va_Mike]

So what is the best book to get for trouble shooting this truck? I am starting to try and sort out the wiring under the hood and need some wiring diagrams to be successful.

 

[BlackNoma]

So what is the best book to get for trouble shooting this truck? I am starting to try and sort out the wiring under the hood and need some wiring diagrams to be successful.

You're reading it right now. Haha.

These guys on here will help you out better than anything I have ever found.

 

[Va_Mike]

I understand that, That's why I have been using this site as a reference for a long time. But that being said A book to make notes in and Highlight while I am tracing wires or running new ones is needed.

 

[Kizer]

Shop manuals .. ebay for around $150 for the whole set or about $30 on CD.
Money well spent, in my opinion.

I have a couple of IH engine manuals for my bullnose trucks and the full set from Ford ... I use them every week.

 

[nostrokes]

Like kizer said shop manuals are the best. I think LMC truck sells them too.. I've gotta get a set for my 63 uni.