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Dan, Technician
Category: GMC
Satisfied Customers: 23789
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Databases
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I put injectors in a customer's lb7. It ran 2 weeks, then

Customer Question

I put injectors in a customer's lb7. It ran for about 2 weeks, then stalled while driving. We have no pressure according to the FRP on the diagnostic tool. When we pull the return line off and crank the engine it has an excessive rate of return fuel. Could the relief valve in the junction block be bad?
Submitted: 1 year ago.
Category: GMC
Expert:  Dan replied 1 year ago.

Hello, my name is***** definitely sounds like the relieve valve inside junction block is problem, nothing else would cause pressure going back into return line like that so you will need to replace the junction block. Here are replacement instructions, let me know if you have more questions. Thanks



Customer: replied 1 year ago.
Is it possible an injector could have caused this?. I know one can cause a no start due to high return, but can it cause it to stall also? Been a Gm tech for 22 years, but just recently started working on diesels
Expert:  Dan replied 1 year ago.

Injector could not cause fuel to go back into return line at a high rate. Injector would also usually set specific injector codes. Let me know if you have more questions, thanks.