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Discussion Starter #1
A friend purchased this 06 C5500 from auction in this condition. So I have absolutly NO history on the truck. Its been well taken care of, and is very clean. I started with the basics, cleaned all the batt terminals, made sure it had fuel, pump the primer hard, hooked up my efilive, watched rail pressure during crank which has hit 2200psi. I have absolutly NO codes. I did unplug #2 injector and cranked, code came up right away, so the ecm is working. I verified this by plugging the ecm into another truck, which fired and ran fine. I then gave it a quick shot of starting fluid (yes i disconnected the grid heater) and when rpm ran up rail pressure got to 12,000 psi
I back probed an injector and got no voltage. so it seems the ecm isnt firing the injectors

today im taking my tech2 to it to see if I can get any info from it that way. But was wondering if anybody had any ideas


thanks, Skippie
 

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Isnt the high pressure side supposed to be around 26-29,000 PSI ? I think you may have a low pressure problem ….CP3 or pressure relief valve?
 

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Discussion Starter #3
During crank, the ecm doesnt fire the injectors till 1450psi. At idle theyre typically 5000-6000psi the 29,000 your thinking is full throttle, full load.

Like i said ,iv seen 2200 while cranking, and 12,000 on starter fluid. So even if it was a but low on crank 12k is double idle pressure.

I messed with it a bunch today but no where further ahead.
 

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Check to make sure your ECM is outputting a 5V reference for the sensors, MAP, MAF, etc. If no 5V recerence output, engine will not run, or will not run very well and starting will be very difficult. Have you plugged a scanner into the CLD? DIdi you have any indication that the scanner couldn't communicate with any of the modules, BCM, EBCM, etc? Could be thta the GMLAN is not in working order.
 

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Discussion Starter #5
I had my tech2 hooked up yesturday and went thru each modual looking for anything unusual, codes, lack of connunication....ect Everything looks fine. I controlled anything i came across with the tech2 just to make sure it could. And again i had no issues.

Im thinking every injector has to be stuck closed. Or most of then anyways. Only thing i can think of.

Todd
 
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