Crank, no start

[zshawnz]

Hello,

First, I swapped a NON DOD 5.3 that had been rebuilt with my blown up 5.3 DOD motor. Both GENIV. I put my intake and injectors on it. After a lot of trial and error I was able to get it running but was having problems with it running rough/low power. Eventually it stopped running all together. When trying to fix what I thought was a connector problem, I ended up shorting out the fuse block and starter. I have since fixed the short I created with the connector, replaced the ground strap, added another ground from the strap back to the block, checked all other grounds and replaced my negative terminal.

After all that, I think the original reason it was running rough was that ground strap from the right rear of the block to the firewall was in pretty bad shape. Now that I have replaced everything I still can't get it to start. It will crank but almost sounds like its not getting gas. I checked the fuel rail and its got gas and the injectors look like they are working. I am not sure if I there is another ground I am missing or if it there is something wrong in the loom that I can't see. I appreciate any help. I am in Pueblo, Colorado if anyone is close by. I feel like its electricial but it could also be bad gas since the gas in it now is about a year old? I put in 2 fresh gallons in and some fuel conditioner/octane booster. At this point the tank is pretty full.

[5FDP]

It won't run without MAP sensor data. You have a code for the MAP and it's also reading 0kpa on that log.

[blindsquirrel]

Also no RPM signal.

[zshawnz]

It won't run without MAP sensor data. You have a code for the MAP and it's also reading 0kpa on that log.

Ok, unfortunately it looks like the MAP sensor is hooked up properly. I was hoping I was getting that code just because it wasn't starting. Same with RPM. Maybe another victim of the short...

New MAP sensor it is.

[blindsquirrel]

Parts cannon! Yay!

I would diagnose the problem instead of guessing.

[zshawnz]

@blindsquirrel I apologize for my ignorance. Do you have any suggestions on how to diagnose the problem? Especially considering what you said previously that I'm not getting an RPM signal? I replaced the MAP and did not have any success. I've looked at every connection and ground I can find and don't see any glaring problems. I have a multimeter but I don't even know where to start with it. Obviously I am in over my head and is the reason I am asking questions. I tried to find a local mechanic to come and help me but unfortunately everyone around here is so busy that I've been told its not worth it for them or it could cost me thousands plus depending on the parts needed. I have also seen where mechanics will do the same "parts cannon" which I can't afford either. I appreciate any help, thank you.

[blindsquirrel]

I'd start with the factory service manual's diagnostic charts for P0107, and after that if you still have a problem the diagnostics for 'engine cranks but does not start'. Service manuals are not really designed for a first-time DIYer but the steps are fairly well explained. Study the wiring diagrams and pinouts until you understand what's there, and then you don't really need a flowchart.

Basically, what the charts will have you checking for is: do you have a good +5v reference, and is it at the correct pin location in the connector? Good ground in the correct pin location? Is the signal wire intact from the MAP connector back to the PCM, and is the PCM capable of reading the signal - can you jumper the signal wire and make the PCM display 5v when you jumper in 5 volts, and 0v when you jumper in a ground? If all the wires are right and the PCM can read what's there on the signal wire, then and only then you can fairly confidently say you have a broken MAP sensor.