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tristan, ASE MASTER
Category: GM
Satisfied Customers: 1610
Experience:  8yrs. exp. ASE MASTER
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2015 lml duramax will not start after replacing the CP4, FRP

Customer Question

2015 lml duramax will not start after replacing the CP4, FRP sensor, and the FPRV . installed a fuel pump at the filter, providing 4 to 6 PSI to the CP4 and still no start. Also it will pressure up at the pump and will hold pressure.
Submitted: 1 year ago.
Category: GM
Expert:  tristan replied 1 year ago.

How much pressure in psi do you have after cranking for 12 seconds?

Customer: replied 1 year ago.
I don't know for sure, as i don't have a guage to check it with. Are you thinking it has a injector leaking off. There is no white smoke coming out the exaust when I Do get it running with a short shot of starting fluid. ( the heater grid wire is unhooked ) Of course, it would be hard to tell with all the emissions hardware still in tact. It idles nice and smooth, with no miss when it is running. It can also be driven with no issues when its running. Turn it off and immediatly try to start it ,and it just cranks. Also it cranks over well , not slow ( normal ).
Expert:  tristan replied 1 year ago.

I've never seen this. Honestly for me to help you need a acantool that view data and check codes because if all it need is a shot of starting fluid and it runs great either the injectors are returning too much fuel to the tank meaning bad injectors or a engine control module not controlling FPR correct. So this meanwhile, crank the engine for 15 seconds 3 times in a row, if it start you need new injectors. Remove the glow plugs and the ignition 1 relay, crank the engine over with a white napkin by the glow plugs ports, if you get a mist replace the injector. Not much else we can do with out a scanner. Thanks