92' B250 engine/electrical question

My ever so reliable 92' Mark III full size van cranked the other day ran at idle for warm up. Three minutes into idling it shut off.
Thinking it was out of fuel because it was lower than normal I added 5 gallons. it didn't crank after cycling the key, the next day it fired right up and drove about 700 feet before dying and not restarting. The next day it cranked right up and drove the exact distance back to where it all started. I figured I would go troubleshoot it a bit ago and it fired right up. I shut it off to see if it would fire back up, it didn't and ether would not make it run. I pulled the coil wire and spun it over but when the key was released it kept spinning over.
So now I am thinking it may be a start/run relay.
It is getting fuel as when it won't start I can smell fuel afterward
Any ideas? I had to replace the PCM 50K ago but it never acted like this. You could drive it however far you wanted when it was bad, you just had to wait a day after you shut it down to drive it again
Thanks ahead

Check for spark, check fuel pressure. That continuing to turn over after releasing the key is weird though. Maybe the ignition switch?

run the codes, see what the computer thinks is going on.

https://www.allpar.com/fix/80s-codes.html

It has a very weak spark when it won't crank, gave it a shot of ether and it won't crank. I can go out there and fire it up right now it may drive 500 ft or 500 miles. Last two times I drove it, the exact same distance each way except for having to push it a few feet to get it into it's parking space.
Had to unhook the battery due to the starter that has never stayed cranking after the key is turned off

When you say "won't crank" what exactly does that mean? To me it means the starter will not spin the engine over.

Do you mean that?

I'm confused now. Did the starter continue cranking the engine over when you released the key?

You need to get the terms correct so everyone understands what you are telling us.

1) Crank or no crank = the starter spinning the motor over, or the starter not spinning the motor over.

2) start or no start = the engine running after the starter spins it over, or the engine does not start after the starter spins the motor over.

3) Spark or no spark = when the starter is spinning the motor over, you have a spark between the plug (or coil) wire and a ground, or while the starter is spinning the motor over, you do not have a spark between a plug (or coil) wire and a ground.

If you have no spark, spraying either into the motor will have no effect.

If the starter is still spinning the motor over after the key has been shut off, you have an electrical problem that may also be effecting the no start problem. It could be an ignition switch, or something shorting out in the wiring, or a bad relay. Gene

When I tried the ether the first time, the starter stayed spinning the motor after the key was released. I unhooked the battery and it quit of course, hooked it back up two hours later cranked the van and it ran fine. I shut it off and of course it wouldn't crank and run. $50 says that I can go out there and it will crank up and run like new

It has weak spark when spinning over

My 92 Dakota had key part of the ignition switch break, there is a lever there that pulls the rod and it broke off. I had to pull the column apart and replace the key part. Just before it died completely, it did some goofy stuff. Maybe your problem as well? Gene

Those things have a bundle of fusible links that connect the power under the hood to the fuse box under the dash. That's always a good place to start researching electrical issues.

Yeah but fuse links are either good or they are not. Intermittent problems are generally not associated with them.

HA!

I've got over 20 years experience with a 92 D250 that begs to differ.

When they get old and crusty they sometimes work and sometimes don't. Every now and then the systems backfeed and pull power from weird places.

Kinda like when I hit the power window switch and EVERY warning light on the dash lit up. ABS, brake warning, water in fuel, wait to start, and all the others would light. I fixed that one and the same thing would happen when I tried to turn on the A/C blower.

Whatever dude, I've been a tech for 45 years now and worked on them when they were brand new and owned plenty over the years. What you just described sounds more like a bad ground. Which can burn out a fuse link. Something those old D and W series are famous for. Bob however is asking about a B van. Similar but different.

Ya know you don't have to thump your chest everytime someone disagrees with you Mr. Mercedes Parts Counter Man. Ok?

I'm not a tech and do not pretend to be one. The fact that I toss parts to techs means nothing in this situation.

I'm sure in your 45 years of fighting cars you've had some serious electrical head scratchers.

In my case, fixing grounds helped some of the issues but did not fix all of the issues. The weirdo malfunctions and mishaps went away when I removed the bundle of fusible links and replaced them with a maxi fuse block I scrounged from a Cadillac in the salvage yards.

Those old fusible links get the crusty green death over the years. Sometimes they carry current well, other times they don't. They looked fine from the outside but 27 years of life under the hood took a toll on them.

They may or may not have anything to do with the issue he's having but it's not going to hurt to check them for proper current capacity.

I want to thank all of you. I figure I am going change parts and clean connections and grounds until it runs consistently. I figure the 27 year old parts probably need changing anyway. I'm going to start with the ignition switch and start/run relay after I clean all connections and grounds concerned. I figure the $400 I paid for the van and the 60,000 miles I have put on it along with the family road trips we have taken I can afford to put it into it.