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I hear you there. I'm just a backyard mechanic. I would think I'd have fuel in the oil by now if I was loosing pressure though an injector that quickly? As little as I'd use it I'm probably not going to buy a lot of diagnostics equipment. Might have to take it to a shop to get to the bottom of it. I really don't mind the fact I already changed the fuel pump as the new one is much quieter than the old one. Other than having to turn the key twice the car runs great and have been living with it since last summer.
I hear you there. I'm just a backyard mechanic. I would think I'd have fuel in the oil by now if I was loosing pressure though an injector that quickly? As little as I'd use it I'm probably not going to buy a lot of diagnostics equipment. Might have to take it to a shop to get to the bottom of it. I really don't mind the fact I already changed the fuel pump as the new one is much quieter than the old one. Other than having to turn the key twice the car runs great and have been living with it since last summer.
Yes, without the right diagnostic equipment it comes down to just firing the "parts canon" and that's not always good...you will not be losing that much fuel through the injector to have the pressure bleed down like that...if you take it to a shop I'd see if they have the hose adapters to diagnose it...Kent Moore is the "special tooling" supplier for GM...if they don't have them they will only be guessing too...I don't like to guess !!...the Mityvac method is just a quick way to check for a bad check valve...good luck !!
Other than having to turn the key twice the car runs great and have been living with it since last summer.
I have been experiencing the exact same issue since September of 2020 on my 2001 C5 with 75,000 miles. My research was similar to yours. I looked at the Delphi Fuel Pump which mentioned an internal check valve, but could not find any info on if that was a substitute for the in-line external check valve. I did buy a used external check valve harness for a 2002 from VetteNuts and Marc at VetteNuts said his Dad's C5 had the same check valve fail (and that was his problem) - I have still not installed it yet, but when I blow in one end of the replacement, it does stop "air" flow from my lungs. guess that is a good sign? I also wonder if the filter/regulator could be a source - not sure if the "regulator" affects that?
Sometimes it takes 3 primes to get it to start, usually 2 primes does it, but last week it was starting on the first try every start through about 25 starts until I filled up with fuel and now it is back to 2 tries.
My thoughts were the same as yours. I blew into the feed from the new pump and also a vacuum and it does have a flow check inside from what I'm seeing. I have ordered a new filter/ regulator because it can't hurt considering the age of the car. Cheap replacement so why not? Will post when installed.
My thoughts were the same as yours. I blew into the feed from the new pump and also a vacuum and it does have a flow check inside from what I'm seeing. I have ordered a new filter/ regulator because it can't hurt considering the age of the car. Cheap replacement so why not? Will post when installed.
Please do!
That is one good thing about throwing new parts at a 21 year old car - even if it doesn't fix the problem, everything is due for replacement anyway!
Ok guys, I replaced the fuel filter/pressure regulator five days ago and it has taken care of the issue! Car starts right up first try now. Big thanks for the information here that steered me in the right direction. Pretty cheap fix.
Ok guys, I replaced the fuel filter/pressure regulator five days ago and it has taken care of the issue! Car starts right up first try now. Big thanks for the information here that steered me in the right direction. Pretty cheap fix.
Ok guys, I replaced the fuel filter/pressure regulator five days ago and it has taken care of the issue! Car starts right up first try now. Big thanks for the information here that steered me in the right direction. Pretty cheap fix.
hopefully it doesn’t come back! My issue comes and goes. Haha. I’ll have it for a few days/weeks then it’s gone for a while. Strangest thing.