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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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1999 5.3L chevy Silverado. The initial problem was, truck

Customer Question

1999 5.3L chevy Silverado. The initial problem was, truck would start, idle 10-20 seconds start stumbling and die.
JA: The mechanics have tons of experience in that area. Are those all of the "symptoms"?
Customer: No....
JA: What else is going on?
Customer: I have replaced the fuel pump assemble, fuel filter, fuel pressure regulator. Ran a scan with a current snap-on modus ultra... No codes present. I finally unplugged the mas-airflow sensor and drove it from a parking lot to home where i did further checking. scanned it again, the only code was the mas-airflow sensor. So I have replaced the max-airflow sensor, crank position sensor, MAP sensor. Had the truck to the chevrolet dealer and they tried over 9 hours testing, they tried (2) new GM mad-airflows, (2) new GM ECM's, temporarily rewired new wires to the mas-airflow... No help. Then they (Chevy Dealer) wanted to replace the new fuel pump assy. I just replaced, even though it is supplying 52 psi while running and 60 psi during surges or if the pressure regulator is unplugged, oh they replaced my new regulator with a GM one also....
JA: Anything else I can tell the Chevy Mechanic before I connect you two?
Customer: The only sensor I haven't replaced yet is the cam position and the 2 fwd O2 sensors.... They look fine while graphing them on the modus ultra. Prior to this the truck has been running fine no issues, it on has 73000 actual miles.
JA: Got it. Let's get this figured out. I'm sending you to a secure page on JustAnswer so you can place the $5 fully refundable deposit now. While you're filling out that form, I'll tell the Chevy Mechanic about your situation and connect you two. You'll be on the road in no time.
Submitted: 1 year ago.
Category: Chevy
Expert:  AMEDEE replied 1 year ago.
Hello and welcome! My name isCustomerand I can assist you with your question. Are there any codes in the computer? Would you be willing to speak on the phone?