I am in the process of troubleshooting my all too common 03 no start issue. It runs fine once it starts. I have flow and pressure tested lift pump it’s OK. I have flow tested the high pressure pump it is fine. The rail pressure is 5500 to 6000 psi at idle. I re-torqued the fuel injector feed tubes. It started good for a few days after but it’s back to its old tricks now. I have tested the FCA it’s OK. I want to do the fuel pressure limiting valve return flow test. I also would like to do the injector return flow test. Could someone post the procedures to do these tests? Or if anyone has any other ideas I would be grateful to get them.

Phil
03 QC 4x4 stock on mods

 

the only thing that fixed mine was 6 new injectors

 

do you know what was wrong with your injectors? cracked body, tips, ball seat erosion?

 

Check your COV. Take it out and see if there is any dirt in it. If not, your probably going to be needing injectors. The COV has caused a few guys to have hard/no start problems. I hope for your sake the COV is dirty.
Good luck,
Topper

 

I will check the COV. It is now throghing a P0251. I did discoect the FCA when I tested it. Not sure if it is bad or I caused the code to come up. I never got a CEL just a P0251 no other codes. My Auto enginuity scan tool software is not conunnicating corectly I have talked to them and they are aware of the issue and are working on a fix. Some of the enhaced moddules won't comunicate fully with some ECMs. So can I clear a code by disconecting the neg battery cabel for 20 sec like the old days?

 

I have had mine disconnected over night and the code was still there.

 

Not just the COV, but check the rail pressure relief valve too. Just replaced mine, wouldn't start but ran fine after a small shot of ether got it going. Fuel pressure (post filter, pre-CP3) appeared low because the CP3 was moving a lot more fuel to feed the leak and still make rail pressure. The aftermarket carter couldn't keep up very well with the additional flow.. fuel in the tank got warm pretty quick too, with the fuel being returned off the rail.

FYI - Mark