How to identify and repair a leaking fuel pressure regulator (GM CPI system) part 1

The CPI system began on the 4.3L engines in the early 90s and extended to the 5.0 and 5.7 engines around the same time with some slight variations. Around 1996 the CPI system became a SCPI which stands for Sequential Central Port Injection. The CPI had one central electrical injector, while the SCPI had an individual electrical injector for each cylinder. On both types there where mechanical "poppet nozzles" that sprayed the fuel into the intake runners. These systems had unique problems due to the injector assembly locations and the mechanical injector poppet nozzles. The vehicle being tested in this video is a 1995 Chevy S-10 Pick-up 4.3 L VIN W engine. The primary focus of this video is how to troubleshoot and repair a Central Port Injection system with an internal fuel leak. Some other names for this system: - central port injection (CPI) - "spider injector assembly" - vortec injection system Engine Performance Diagnostics chapter 16 page 8 Symptoms: - long crank time - severe rich running condition (P0172, P0175) - more gas mileage - check engine light - misfire trouble codes (P0300) - rough idle - stalling Fix: - replace fuel pressure regulator Testing procedures shown: - how to test fuel pressure - how to manually energize a fuel pump on a GM - how to determine if you have a fuel pressure bleed-down problem - how to determine the cause of the bleed-down problem - how to verify the the location of the leak that is causing the bleed down problem - how to replace just the fuel pressure regulator on the injection assembly - what to look for using an aftermarket part (you may break the housing!) Tools used - fuel pressure gauge - jumper wire - needle nose vice grips - scan tool Playlist - (Chapters 14, 15,16) Fuel Delivery and Fuel Pressure Testing https://www.youtube.com/playlist?list=PLAFYVCyenqcrstVqfSc1PCbQ1pebuNIO6 Related videos: - How to identify a leaking fuel pressure regulator on a GM CPI system (part 2) https://youtu.be/dAAFM3zlJME - Fuel psi less than 50 psi = no start (GM CPI Vortec) https://youtu.be/yjQY613sql4 For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book. Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium https://www.scannerdanner.com/join-scannerdanner-premium.html There is a 14 day free trial. On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere! Disclaimer: Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.