What's your resistance? It's possible that a bad connector or frayed wire would be building a lot of resistance. Also make sure to pull and check the plug AT the ignition module for corrosion. (module, not the tumbler).

 

Where is the ignition module?

Could the starter be at fault? Losing 2 volts at cranking?

I took the battery into O’Reilly’s and Napa to have it tested. I didn’t like the guy at the big green O as far as I could throw him.

I’ll see what I can do but it might be a couple of days before I can get to it. I took today off work because tomorrow will be about 14 hours….

Thanks for the help so far!

 

there is NO ignition module , your truck has a PCM mounted inside the left fender behind the battery , have you checked CODES [ procedure link below ]

also you should have full battery voltage to the fuel pump as it comes right from the Alt power

DODGE CODES PRE-95

The 1980s-1990s Chrysler vehicals . Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. (On is not start!) The "check engine" light will flash. Count the flashes Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH...

www.ramchargercentral.com

 

before you say anything 1991 is the same and i,d say your Dist pickup was bad

 

Voltage at the pump (back probing) is …. Nuts, I don’t remember now. I know when cranking it’s only about 9.2V but you can see a spike to 11+ just as you stop cranking. I kid you not, my wife releases the key and there’s a spike and then it’s gone.

I HATE ELECTRICAL ISSUES!!!!!

 

Oh, on the codes. I’ve got nothing. I get the check engine light coming on for about two or three seconds and then shutting off. No blinking codes for check engine light.

 

you are reading the link and following the procedure to the letter , because even if there are NO codes you should still get codes " the start and end " codes of the procedure

so if you are doing it right there are still codes

 

there is NO ignition module , your truck has a PCM mounted inside the left fender behind the battery ,....

Whoops, my bad. I've never owner a dodge truck late enough to not have the ignition module.

Now, I don't know what it would look like on a 91, but I've got a 56 International that has an add on electric fuel pump. It would go out at sporadic intervals. After it'd cool off it'd fire right back up. Last year I was on my way home and it started dying and I hit a bump then it came back on. So I reached under the dash and could push up on the wires running to the dash mounted switch and the pump would stay running. Then I got the bight idea to follow the wires to the switch to see if the connector had backed off. Turned out it was insanely hot due to a loose/rusty connector. I ended up ordering another switch and nursing my thumb for a week or so. It was like grabbing a soldering iron. Anyhow, even the switch might be worth looking at if nothing else turns out wrong.

 

you are reading the link and following the procedure to the letter , because even if there are NO codes you should still get codes " the start and end " codes of the procedure so if you are doing it right there are still codes

 

OK, you are so awesome! To be honest when I did the test for the codes it was the first time I remember seeing the check engine light off since I’ve owned this truck. I just needed to wait a little bit longer to get the codes… Here they are I think…
12
41
Then 55 for then end.

I just needed to have a little more patience….🤦🏻‍♂️

 

41 is a no-charging code that you'll have to address once the vehicle is running. The only blind part I would through at this is the Hall-effect sensor in the distributor. It's known to not throw a code when bad, maybe more often than not.

 

Since it runs on fuel poured into the TBI, you need to address the fuel pump issue. I'd check to see if you are getting enough pressure from the pump.

 

The pump works and has intact wiring - "I ran a jumper across the ASD to get the fuel pump to run, it runs and doesn't stop". The issue is the signal telling it turn on.

 

But then it should run and keep running if the ASD is jumpered.....but yeah, the signal is another issue so it doesn't have to be jumpered.

 

I thought he meant it kept running as in the truck kept running. Now I see he might mean just the pump. He should check fuel pressure then or look at fuel spray at least. Would be silly if this thing was out of gas...

 

Sorry I wasn’t clear enough. When I jumped across the ASD the PUMP runs consistently. It’s not out of gas, it’s got about 8 gallons in it. I’ve dropped the tank about four times now and decided siphoning 15 out more gallons was ridiculous… I’ll see about fuel flow on theTBI. what’s the easiest way to check pressure in the fuel line?

 

Ok,
1- didn’t/couldn’t see any fuel spray when looking down TBI while cranking.

2- Checked the injectors with a 9 V battery and you can hear them click as you touch it on and off the injector pins.

3- While cranking, about .65 V to injectors (according to my Harbor Freight voltmeter)

 

In the past I’ve disconnected the fuel line and couldn’t get it to pump anything out but does it need to be a closed system to build fuel pressure?

I don’t have have a fuel system pressure tester and obviously can’t drive it to the auto parts store to borrow theirs. Is there a ******* way to check fuel system pressure?

 

I would think you can disconnect the fuel line and, being careful with the line, jump the relay. You should see it pour out. that will immediately tell you where the problem is - injectors/throttle body/etc vs something wrong in the tank or lines (kinked, rusted through somewhere, etc)

 

the dodge TBI system runs on 14.5 psi fuel pressure , the pump should have out of the ASD relay full battery voltage , the line you wanna check is the rear facing lower one [ see diagram ]

 

You can borrow a fuel pressure tester from the auto parts store. They don't typically test it. You'll want to make sure it builds pressure. Flow is one thing, pressure another.

 

l,m gonna explain the dodge tbi starting procedure in a nut shell , you turn key to ON , PCM turns everything ON for 3 to 5 seconds and checks for signals then shuts everything OFF , you turn key to start and motor turns over and the PCM looks for a DIST signal and once it gets it , it turns everything back ON , so if there is NO Dist signal the engine will NOT run , if the PCM gets the Dist signal it fires right up

 

The OP's original statement was "It's getting spark because I can run it fine on starting fluid or pouring fuel in the TBI but the voltage is too low to get it to the TBI. ". I think we're back to checking fuel delivery.

 

So, the latest...
1. Remove fuel line behind TBI and plenty of flow to that point.
2. Tested and replaced ASD connector, had a corroded connector, right now it doesn't actually have a connector, the wires are going right to the ASD
3. Tested continuity from the 60 to the ASD, it's good.
4. Now something else is wrong because it won't fire on starting fluid, not even so much as a hiccup...
5. Still not getting fuel through the TBI, looking down the throat while someone turns it over and ...nothing...
6. I also made sure to add gas to the tank to make sure it wasn't empty
So now not only is it not getting fuel but it doesn't seem to be getting spark, quite possibly I screwed something up there with doing all this stuff and a bunch of stuff I did before that I've either listed or totally forgotten about.

Any suggestions? I hope this clears things up for someone because I haven't a clue...