Done injectors,,,, wont start

nwodiesel

New member
Mar 29, 2014
78
0
0
Thunder Bay, Ontario, Canada
Hi I know iive had a few posts of late but I just buttoned up the injector install.....filled er up with dexcool... primed the shit outta it and no????? My fass pump is out for warranty...and ive just unioned the two lines thinking the cp3 will do well enuff to run it in the shop. Do I have an air lock? any help appreciated .
 

sweetdiesel

That's better
Aug 6, 2006
10,390
0
0
52
Thailand
If you could log it that would be helpful! You need X amount of pressure and X amount of voltage for our trucks to fire.

did you use new gaskets on return lines and verified they are not leaking? If it won't build pressure u might have a bad cp3, or possibly a stuck open injector. If you have a old fuel rail line you can use it for diagnosis along with something that reads rail press.
 

C.bowles2

2005 lly duramax
Nov 16, 2013
489
0
16
Ohio
Pump primer and bleed at filter housing, then pump again and bleed the line where the test port is. Use a pocket screw driver to press in the valve. Then pump again and crank. I believe these need about 700 psi to fire injectors or something like that.
 

Jp03Duramax

New member
Aug 3, 2014
2
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0
I have a 2003 Duramax which was idling rough and dumping fuel into the oil so I replaced the injectors primed the system and now it will not start! My fuel pressure with the Key on is 253.8 - 279.9psi when I start to crank it goes up to 407.5 psi I disconnected the glow plugs and tryed starting it with starter fluid and it starts but then goes off the minute I stopped putting it in and my Fuel pressure goes up to 3000psi but doesn't stay running!
Do you think I need a new CP3 pump, and how good it just go bad when I was running before I put the injectors in?

Please Help!
 

Jp03Duramax

New member
Aug 3, 2014
2
0
0
03 Duramax won't start after doing injectors!

2003 Chevy Duramax 170,000 miles 5" exhaust
K&N air filter

I have a 2003 Duramax which was idling rough and dumping fuel into the oil so I replaced the injectors primed the system and now it will not start! My fuel pressure with the Key on is 253.8 - 279.9psi when I start to crank it goes up to 407.5 psi I disconnected the glow plugs and tryed starting it with starter fluid and it starts but then goes off the minute I stopped putting it in and my Fuel pressure goes up to 3000psi but doesn't stay running!
Do you think I need a new CP3 pump, and how could it just go bad when I was running before I put the injectors in?

I've prime the system on your times craft one injector nowhere feel real pressure still at 407psi while cranking! About to buy a new CP three pump and fuel pressure regulator but I don't know how this could've gone bad when It was just working before!

Please Help!
 

dirtydmax

<---up shit creek
Sep 1, 2013
1,091
4
38
46
muskoka,Ont Canada
2003 Chevy Duramax 170,000 miles 5" exhaust
K&N air filter

I have a 2003 Duramax which was idling rough and dumping fuel into the oil so I replaced the injectors primed the system and now it will not start! My fuel pressure with the Key on is 253.8 - 279.9psi when I start to crank it goes up to 407.5 psi I disconnected the glow plugs and tryed starting it with starter fluid and it starts but then goes off the minute I stopped putting it in and my Fuel pressure goes up to 3000psi but doesn't stay running!
Do you think I need a new CP3 pump, and how could it just go bad when I was running before I put the injectors in?

I've prime the system on your times craft one injector nowhere feel real pressure still at 407psi while cranking! About to buy a new CP three pump and fuel pressure regulator but I don't know how this could've gone bad when It was just working before!

Please Help!

Try starting a new thread so everyone can see what you have going on as well as filling your sig.hope you get it figured out!:)
 

Cknight199

New member
Aug 23, 2012
1,827
0
0
Salt Lake City, Utah
I just did mine as well. I don't have a fuel filter/primer so I just ran the key for a couple seconds to get the fass pumping and then cranked three times for about 10-15 seconds each.