New to me 2000 K2500 missing at idle, occasional stalls

[HotWheelsBurban]

I just reached behind the intake to see what it was I plugged in and I'm positive it WAS the distributor computer wire.

So many questions, how did it get me from Wisconsin to the twin cities with that unplugged. With no codes.

It's a 400, they'll run when stuff is weird more than other vehicles.

 

[Nicman201]

It's a 400, they'll run when stuff is weird more than other vehicles.

So what does the distributor computer wire do? It clearly doesn't do anything to the tachometer like I've seen on an older 350. Did they possibly remove the wire (I believe you have to do this to get base timing on older generations?), then verified the cam offset with the scan tool and forgot to plug it in? Then I plugged it in and it made it run weird?

That's a lot of questions and hypotheticals. Lol. I'm just curious as to how all this works. Entirely new platform for me.

 

[Schurkey]

The oil pressure switch would also be 3 wires, and "right next door" to the distributor. But you'd know if that were unplugged, your oil gauge would be at 0 and the "Check Gages" light would be glowing.

 

[HotWheelsBurban]

The oil pressure switch would also be 3 wires, and "right next door" to the distributor. But you'd know if that were unplugged, your oil gauge would be at 0 and the "Check Gages" light would be glowing.

If oil pressure sending unit is unplugged, wouldn't that also keep it from running ( since the computer thinks there's no oil pressure)? Or is that just on OBD II and Vortec?

 

[Nicman201]

The oil pressure switch would also be 3 wires, and "right next door" to the distributor. But you'd know if that were unplugged, your oil gauge would be at 0 and the "Check Gages" light would be glowing.

Definitely the distributor wire, I have oil pressure on the dash and no warning lights.

 

[Schurkey]

If oil pressure sending unit is unplugged, wouldn't that also keep it from running ( since the computer thinks there's no oil pressure)? Or is that just on OBD II and Vortec?

If the fuel pump relay is working right, "no oil pressure" won't prevent the engine from running.

Doesn't matter about OBD II or Vortec.

Far as I know, the oil pressure sensor doesn't communicate with the computer. Just the fuel pump and the instrument cluster.

 

[HotWheelsBurban]

If the fuel pump relay is working right, "no oil pressure" won't prevent the engine from running.

Doesn't matter about OBD II or Vortec.

Far as I know, the oil pressure sensor doesn't communicate with the computer. Just the fuel pump and the instrument cluster.

Okay, cool, thanks. Wasn't sure, because my TBI truck experience is many years ago.

 

[someotherguy]

Sounds like the connector he's talking about is the cam position sensor (CMP) - I do believe the PCM will compensate if there's no signal from this, allowing the engine to run. Been too long for me to say with any degree of certainty, so others will have to chime in. Clearly it did run as OP has been driving the truck with it disconnected. Most likely, they simply forgot to plug it in after they installed the new distributor. Out of sight, out of mind. The distributor on a Vortec 454 is very much out of sight behind that big intake..

Richard

 

[Nicman201]

I'm getting the feeling the guy diagnosed the hell out of it and gave up and that's why he let it go.

Could it be the EGR? I disconnected for ***** and giggles and it's a super steady idle. Haven't driven to test cause the rear brakes are out at the moment

The way it seems to cut out on me when driving feels fuel related, or just a hard misfire I'm not sure. Haven't forgoy about fuel pressure test, just haven't had a chance to go rent the tool yet

 

[Nicman201]

I'm getting the feeling the guy diagnosed the hell out of it and gave up and that's why he let it go.

Could it be the EGR? I disconnected for ***** and giggles and it's a super steady idle. Haven't driven to test cause the rear brakes are out at the moment

The way it seems to cut out on me when driving feels fuel related, or just a hard misfire I'm not sure. Haven't forgoy about fuel pressure test, just haven't had a chance to go rent the tool yet

Ok, EGR seems unrelated. I had the distributor wire unplugged still from earlier. Just plugged it in after idling for 5-10 minutes, instantly had a horrible idle. What does this mean? You called it a cam position sensor, but it most certainly is the 3 pin connector at the base of the distributor