Hmm.........perhaps my block heater is bad then. It'll start in warm weather but, won't start in cold weather even after having been plugged in for several hours.

 

how long does it turn over before starting?

it could very well be a tired starter.

 

Like i said before, a new battery can have a bad cell.

Do the separate battery start test. See if it'll start on either battery alone.

also, are you getting diesel when you crack an injector line?

 

Well as it turns out, this truck does indeed have an external voltage regulator and while the alternator looked brand new, the VR most certainly did not. In fact, it looked rather weathered so.............I replaced it.

This morning, 39° outside, it fired right up after less than 2 seconds of cranking. I have no explanation of why replacing the VR worked but, it did.
We drove it 3 times today and it fired up right away each time.

Before, it wouldn't start unless it was at least 50° outside.

 

Weird indeed. I was under the impression that the VR didn't impact starting ability, but rather, it impacted how the alternator charged. So if you had charged up batteries, it wouldn't matter about the VR.... but IDK. I got rid of my VR years ago.

I thought someone said you had a 3G alternator, therefore you don't have a VR? Do you have a 3G? If yes, you should figure out how to eliminate the external VR with new wiring, so that might be impacting your electrical system.

 

Only thing I can think of is maby you moved/disturbed some wires near it and got a good connection?
Or, perhaps the old one was shorting to ground, dropping the voltage on some wire enough to prevent VSS power from being high enough?

I'm really reaching here. There should be no way that that worked... but evidently it did.

 

Well......it's still working. It was 36° this morning and again, it fired right up.

I have no idea how to tell if it has a 3G alternator but, I don't really care because I'm not touching it. As long as it's starting and there are no other problems, I'm going to just leave it be.

 

If I were you, I would not just leave it. For all intents and purposes, replacing the VR should not have fixed your situation, but somehow you have temporarily got it running. I'm pretty sure you will encounter this problem (or a tertiary problem) in the near future if you leave it as is.

First off, determine which alternator you have. Which one looks the most like your alternator.


The typical late 80's Ford Diesel Alternator (1G) looks like this:






If the PO replaced the old 1G with a 3G, it would look somethign like this:






IF, your alternator is a 3G, it should NOT have a VR. I'm 99% sure it will conflict with the internal regulator, and if the PO has wired it wrong (which it appears to be), then you have a whole host of potential issues.

If you have a 3G, then you have all the hard parts done already. Here's a great article on how to wire the 3G into our old trucks. I did it. It was pretty simple. Just trace your wires back to the appropriate parts, and make sure you are good.

 

It's a 1G alternator.........apparently this one was never upgraded.

Did a few more tests and it looks like the engine block heater has been the culprit all along. It starts and runs fine in mild to warm weather, just not when it's cold.

I found a bad spot in the wire going to it and repaired it but, it still doesn't seem to be working.
The problem is, I don't know exactly which one it has and there's over a dozen listed for it at the parts store and they are all upwards of $100 or more. Even then, where it's located makes it nearly impossible for me to get to with the truck sitting in my driveway. It's in a freeze plug hole that sits directly over the engine cross member.

Rather than paying a shop to replace it, I'm considering a cheaper fix (just in case that's not the actual problem) by getting a KAT'S engine heater. It's a magnetic heating unit that you just stick on the bottom of the oil pan and plug in. The local parts store sells them for $49.

 

the stock block heater is 1000 watts.
those magnetic 100 watt units are worthless.

i take the wire off the heater and test each wire independently with an ohm meter. usually the plug end id bad. i replace them with a good external replacement plug from lowes or home depot.

 

^^^^ +1; it's usually the cord. Check the resistance right at the heater itself. Should be aprx. 13 ohms.

 

It's a pain, but you *can* get to the block heater without removing anything, in the driveway. You get to it from the bottom, and count on getting some coolant on you(so get the truck warm first)
Make sure to release all the pressure and then close the cap so you have a vacuum in the system as the engine cools; this will allow you to replace the heater without draining all the coolant(though you may lose a quart or so, max).

That being said... Unless it's going to be less than 20F, don't worry about it. An IDI with a good glow plug setup will fire right off at 20F without needing to be plugged in. Below that, it's more a matter of fuel gelling than anything, until you get to like 10F and below.

So, fix the glow plug setup so it starts right, then fix the block heater when you get a chance.

Also, just check Ebay for a new block heater. You can pick them up for $50-$60; You just need to find one that fits our engine, even if there are multiple designs. Usually, they come with a cord, so you don't need to worry about that.

 

On the vans, the block heater is very easy to access. One of the (few) benefits of an IDI van over the IDI truck.

 

I performed the "power on" test of the injector pump. There is a very audible click when I disconnect the wire and while it does indeed click when I reconnect the wire, I can barely hear it.

Next, I disconnected one of the fuel lines from an injector and observed while a friend tried cranking it. A very small amount of fuel came out (maybe 2 drops) after 10 seconds of cranking and even that barely dripped out. I got more than that when I disconnected my test gauge from the port on the fuel filter block.......a LOT more.

I tried looking up the injector pump online just in case it needs a new one but, they are about a grand each and none of them look like the one I have.
All the ones shown, have a separate port for each fuel line but mine, has just one port that feeds into a block, which then splits into the 8 fuel lines.

 

never seen anything like that before. can you post pictures?