Hi everyone,
I had my 04 trailblazer i6 parked for almost a year doing some repairs and few modifications in that period it had almost a full tank and i kept starting it up regularly to warm up but didn't drive it (seats were out) it took me a while to realize that fuel can go bad sitting in the tank so after about 7 months i siphoned out as much as i could from the tank and putted about a two gallon of fresh fuel in and crank it but i won't start at first but starts after 2nd or 3rd timet It'll rough idle for awhile then it runs better, there's one time it was idling very rough until it shut off by itself.
I was suspecting a low fuel pressure so i did a fuel pressure test and here's my findings:
Turning the key to ON i see 0psi but i can here the pump turn it OFF and ON again i get a little pressure but it drops down rapidly it doesn't hold pressure not even for a second.
When trying to crank it i see the fuel pressure rising but it won't start it'll start after second or third attempt but with fairly low pressure around 40-35psi but it stays in that range idling.
Once i turn it off pressure drops immediately.
In this video i cycled the key ON and OFF few times to show its behavior.
I'm guessing this is either a bad fuel pump or a major leak somewhere so i did a visual inspection for any leaks and i couldn't find anything.
To isolate the pump and fuel injectors first i pinched the main fuel line near the fuel rail and nothing changed, Since all points to an issue with the pump so just to be sure i disconnected the main fuel line and put it inside of a bottle as shown in the video below, i turned the key ON i can hear the fuel pump but nothing is coming off the fuel line, second try i get a little bit of fuel but no pressure coming off the fuel line tried it few times same thing, the fuel smells awful and it has a bright yellow color and feels a bit oily definitely bad.
My conclusion i have a bad fuel pump that needs to be replaced alongside the fuel filter and cleaning the fuel injectors as well.
Was my testing method and conclusion sound?
I'd appreciate any input. Cheers!
I had my 04 trailblazer i6 parked for almost a year doing some repairs and few modifications in that period it had almost a full tank and i kept starting it up regularly to warm up but didn't drive it (seats were out) it took me a while to realize that fuel can go bad sitting in the tank so after about 7 months i siphoned out as much as i could from the tank and putted about a two gallon of fresh fuel in and crank it but i won't start at first but starts after 2nd or 3rd timet It'll rough idle for awhile then it runs better, there's one time it was idling very rough until it shut off by itself.
I was suspecting a low fuel pressure so i did a fuel pressure test and here's my findings:
Turning the key to ON i see 0psi but i can here the pump turn it OFF and ON again i get a little pressure but it drops down rapidly it doesn't hold pressure not even for a second.
When trying to crank it i see the fuel pressure rising but it won't start it'll start after second or third attempt but with fairly low pressure around 40-35psi but it stays in that range idling.
Once i turn it off pressure drops immediately.
In this video i cycled the key ON and OFF few times to show its behavior.
I'm guessing this is either a bad fuel pump or a major leak somewhere so i did a visual inspection for any leaks and i couldn't find anything.
To isolate the pump and fuel injectors first i pinched the main fuel line near the fuel rail and nothing changed, Since all points to an issue with the pump so just to be sure i disconnected the main fuel line and put it inside of a bottle as shown in the video below, i turned the key ON i can hear the fuel pump but nothing is coming off the fuel line, second try i get a little bit of fuel but no pressure coming off the fuel line tried it few times same thing, the fuel smells awful and it has a bright yellow color and feels a bit oily definitely bad.
My conclusion i have a bad fuel pump that needs to be replaced alongside the fuel filter and cleaning the fuel injectors as well.
Was my testing method and conclusion sound?
I'd appreciate any input. Cheers!
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