2008 Escalade intermittent crank no start

[thompsoj22]

Ok, tonight without getting it to act up; I unplugged the camshaft sensor and tried to start it, and it started and ran. I plugged it back in and unplugged the throttle body- it started and ran. The only thing left I can think of is the engine ecm

as previously mentioned, the tech2 will be your best friend if you plan to keep your vehicle. i got my clone from a vendor on aliexpress for approx $270 shipped to my door fedex from china. I carry it in the car at all times and have "tinkered" with it a few times but the reality is i dont know my ass from a hole in the ground on how to "effectively" troubleshoot with it. They are the single most important tool to have but knowing how to use them takes practice, examples of how to practice are kept secret unknowingly by those who are proficient because "technology" is second nature to them and they simply cant imagine someone not being able to find their way through the multiple commands/prompts to get the answers they need. im not hacking! it is just frustrating to have a tool that has no operating instructions? Go figure that china will rip off the technology to "knockoff" the tech2 but draw the line at operating instructions.lol

 

[Ncsujrc]

Welcome to the forum from Oregon.

You have replaced a lot of things with no help. When you do a crank and no start you need to be checking, at the same time, for spark and fuel pressure then. I could give two ***** what it has when it is running. What color is the spark? Blue=good, orange=bad.

when it is acting up, it has 60 psi fuel pressure and blue spark- will spin over but not start

 

[thompsoj22]

when it is acting up, it has 60 psi fuel pressure and blue spark- will spin over but not start

you are describing an impossibility? Fuel and ignition and not even a pop/backfire? And yet your vehicle is doing it. No codes,YIKES! Intermittent issues are the worst problems to diagnose as you have to troubleshoot when they happen. I think your ECM is a reasonable guess as it could potentially disable all injectors "simultaneously" IE fuel pressure/spark but no start/run. have you checked the ECM connectors for clean/tight/no corrosion? ECM or a tech2, im guessing about the same cost?

It is odd that it only does it as you approach idle? carry a can of electronic "freeze/cool" spray and next time it does it spray half the can on the ECM aluminum body and see if it will restart immediately.

Disclaimer, historically the ECM is rarely the problem. I know that little bit of info dosent help but it is the truth. The ECM is solid state, encased in epoxy resin and should only fail upon a manufacture defect or voltage/amperage mistakes. jumper cables backwards or arcing to ground while the engine is running, remove or install connectors while power is applied are a few.

 

[Doubeleive]

this is where the tech2 will come in handy, if you suspect the ecm you can check the ecm with the tech2, you can check the status of practically any electronic part or you can command it to do what is it designed to do and verify functionality, if the cost of a tech2 is prohibitive then if you have a windows laptop or tablet you can get the vxdiag for $100 instead, it will run tech2 win, which is a software based tech2 and as a plus it does GDS also, best of both worlds.

 

[OR VietVet]

Sounds like the injectors are not being told to pop off/release fuel. Especially if the pressure is rock solid at 60 psi. Does the fuel pressure pulse at all?