So I have a 98 3500 5 speed 4x4 with the v-10. Been working on it for a while. Went through 2 new fuel pumps,(don't believe when they say delphi are the best just more china junk). 4 crankshaft sensors (more chineseum). Finally I've got spark and fuel to the plugs.
I can see in the plugs that they burn the fuel off for they are clean, but of course the truck ain't running. Only thing I can figure is the computer is shot because it won't run🤷‍♂️.
Or unless I'm missing some kind of run circuit🤷‍♂️.
If the computer is shot where is the best place to order one? I was looking at a thread here last month and i saw he bought a (rebuilt) computer but it didn't work.
Any thoughts or ideas would be appreciated.

 

If you indeed have spark and fuel the PCM would be working. However the plugs should be wet with fuel if the injectors are working and the truck is not starting. Can an OBD2 reader talk to the PCM ? Do you get the "tach bounce" (needle is coming off rest) when cranking ? Do you hear the fuel pump when turning the ignition on? Check for power on the dark green/orange wire at either coil, this will only be active when cranking or running.

Can be any sort of thing, PCMs do go bad but it's not that common. Plenty of examples here where a new/rebuilt PCM did not solve the problem.

 

This is why I'm asking. It doesn't make sense to me. Everything you have asked is like I said good, except the truck doesn't have a tach, and of course it doesn't run🤷‍♂️. Unless I'm missing something somewhere.
To me it seems something is cutting the run circuit, the only thing I can figure is something in the computer is cutting off so it won't start.
It just doesn't make sense to me.

 

Fuel pump should prime at initial key on, then, it should run while the engine is cranking. Does it?

 

Just the man I wanted to talk to. Seen you here many times.
So the answer is yes.
First fuel pump i installed was the delphi. Couldn't figure why no fuel. That was last year and had better things to do till now.
Now when I went to work on it, checked everything again and no noise. No noise no pump. Pulled supposed pump and no good. Good thing i cut a hole in the flat bed. Put new carquest pump no pump. Checked fuse🤦‍♂️ well yeah the delphi burnt fuse. New fuse, now it pumps for the few seconds it should while cranking.
Now we get to the crank sensor went through 4 (keep in mind I looked high and low for the good mopar stuff) until I actually ordered the cheapie from Chyna and it worked. So now i got spark while cranking.
Made sure to check the spark from the coils this morning (all of them) at the tools gapping approximately 3/4" wide, they all sparked nicely.
Now to the plugs, it seems the plug threads are covered with fuel while the electrodes themselves are clean (like they sparked and burned the fuel).
But for what reason would the computer not let it run?🤷‍♂️
What am I missing?
I just snapped🤦‍♂️ tomorrow I'll check if it's running while cranking.😁

 

Do you have a scanner that can read live data? If so, see the the PCM thinks engine temp is.

 

Maybe 3rd times a charm?
Answering yesterday's question.
I got 40 psi on the fuel rail while cranking.
No I don't have a code reader with live data but I can order one.
Here's the new stuff I've installed already.
Fuel pump (carquest, last was delphi and no good)
Crank sensor, ( went through 4 finally got a "good one")
Idle air sensor (found a mopar)
Coolant temp sensor (quick from autozone thinking that's what it was 2 weeks ago)
Ignition wires (standard motor )
New plugs ( champion coppers)
Following have been checked and are working.
Cam sensor
Throttle position sensor
Coils (all checked jumping a 3/4" gap in testing tool)
Looking at the plugs after cranking, they all have "wet" threads but the electrodes are clean as if burning for a few seconds.
Also noticed the gauges indicator flashes/dings when cranking.
I don't know what else to try at this point🤷‍♂️.
If I do need an ecu the used are around 400.00 and how long would they last? Rebuilts, looking at one of the last threads i think (rookie?) He got a rebuilt and it didnt work.
🤷‍♂️

 

Fuel pump will charge the system at first key on, It will not run again until the pcm sees the engine running.
It should be 49. No check engine light? Codes? Have you tried to hold the throttle down while cranking?

 

If you turn the key on it does turn the pump on and shuts off until you crank it. It only red 40 psi (quick fuel gauge rig up).
I did notice that it didn't hold the pressure in between cranks (could be my hose to gauge wasn't tight enough) I can smell the fuel, but i dont see any leaks. Maybe an air leak in the o-rings at the fuel rail connection or the pump connection. I was gonna check all that tomorrow.
I did try holding the throttle all the way down, didn't do anything.
Check engine light comes on only when your first turning the key with the rest of the lights.
Code reader didn't read anything.
Guess I'll order a live data code reader.
I guess little by little I'll get there.🤷‍♂️

 

You may just not have enough pressure for it to run. The PCM has a tolerance, but, I think the "Low" is 43 or so, and even at that, it won't run well.