Problems started with a faulty fuel pump.....very long because I wanted to present accurate information...

sunksy

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2018 Chevrolet Silverado LTZ 4x4 5.3L. 135,000 miles.
To begin with.....my truck had the usual symptoms of a failing fuel pump. No buzzing noise when turning the key on, low fuel pressure,
poor overall performance. And difficult to start (at times) but usually gets going after several attempts.

What was done.....I purchased a fuel pump, model 13513407, which was replacement model given from several online Chevrolet Parts
websites. Now where I live at, due to HOA, I cannot work on my stuff at home. Garage is full of junk and can't access the backyard due
to fencing. Even if i could, since its fuel someone would smell something and report me in, I already have a strike with the HOA. So I
found a local mobile mechanic to do the work for me. I researched and found one with a good reputation. The work was performed,
money exchanged, the truck started up quickly, no leak issues that could be seen. Everything seemed to be working fine.

Now the symptoms....truck runs like sh*t. There is this random vibration that can be felt up front in the engine compartment, this happens
whether accelerating or idling, fast or slow. And the engine light comes on constantly. The code is P0455 Evaporative Emission System Leak
Detected (large leak). I took this for diagnostic to seven different shops, including a dealer, and out of the seven, four "master mechanics" have
stated it is a transmission issue. WTF?

Ok so a little more information. About a week after the install, I took it for a ride and filled up the tank. Just kept the hose in until it clicked.
When driving home I smelled a STRONG odor of gas. I pulled over as soon as I could, crawled under the truck, nothing. Couldn't smell anything
while parked. And I know it was me because for a portion there I was the only person on the road. More information, one time it rained here,
not just a drizzle but coming down and it did that for most of the day, I'm in Texas DFW by the way. During the drive to work my truck went crazy,
vibrations like I never felt before and my check engine light was flashing like christmas lights. I found out this usually points to multiple cylinder
misfires. It has done this a second time during another rainy day. Sometimes during acceleration, the vibrations in the engine bay intensifies but
eventually dies out. Mind you this is not a transmission slippage, I know what that feels like. I don't think those master mechanics were correct
in this. So knowing the plugs, coils, and wires have never been replaced I bought a complete ACDelco set (coil pn 12708496, wire set pn
19431551, and plugs pn 41-114). Ok I remember the plugs were replaced at 80,000 while it was still under the service agreement. Even when I did
this, and during another drizzle, it did the same engine light flashing thing and strong jerking/vibrations as stated before. I took the truck to another
service center and his diagnostic was the P0455 code was because of the canister purge valve (a 40 dollar item) and the all my spark plugs were
faulty (about 100 dollars). I had some hope in the canister purge valve but not the plugs, since there are still less than 100 miles on them. I bought
and replaced the valve myself (fyi the shop wanted a thousand just to replace plugs and install the valve, parts would have added more) but I'm still
presented with this scenario. I'm pretty sure if it rains the process described earlier will repeat again. Oh more info, during the last service center
visit i had them test the fuel pressure that the new pump was giving and it passed with flying colors.

So I'm at a lost. Just to point out I had absolutely no issues with this truck before the fuel pump change, the truck took me here to Texas from Arizona
at least 12 times before finally moving here, no problems at all. And I am the original owner, if that makes any difference. Oh yes there were
issues like the radiator shutter assembly failing, a hole in the coolant reservoir, cracked windshield, but nothing big. The truck has been serviced per the
service plan, before it ran out. At this moment I'm looking for another shop or individual that can drop the tank and have a look see. Maybe the leak is
there? And if there is a leak why no spillage? I know gas dries quickly but there'd still be signs. And if so can this scenario cause the engine to act up
in the manner described? I think I will have to find some mom and pop place because the other mechanic shops I have visited weren't willing to drop the
tank just to "see", unless I was to buy a pump from them. I work long hours all week but will check up on this when time permits, any advice or directions
some of you can provide will be helpful. Thanks.
 
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More information. It was raining today, not much, but when I started the truck up noticed the vibration in the engine bay was strong. And sure enough the
check engine light is doing it's flashing. So I hooked up my code scanner, I have an Autel one, and did the DTC on it instead of the simple OBD scan, it
displayed two codes. P0500-00 Cold Start Rough Idle and P0300-00 Engine Misfire Detected.

My truck never did this before at startup, it was always while driving so previous times I was unable to hook up the code reader to it. Maybe I should do a
live recording on my way to work tomorrow maybe someone will be able to use the information.
 
Is your speedometer working?
 
Everything works fine. Some were asking if I was getting a code for lean fuel, but no on that one. On my way to work I'm going to hook up my
reader and record live data all the way to work and see if I can get a shop to analyze it for me. It's a start. P0455 is the only recurring code, I
looked through my scanners history and that is it. Other than the two codes mentioned in the other post. In the history I also found a scan when
the old fuel pump was still in the truck and no codes there, whether it be the OBD, ECM, or the TCM. I did a full scan at the time. All this started
after the fuel pump was changed. And thanks for taking the time to read my posts.
 
Is your speedometer working?
I admit I was confused why you were asking about the speedometer, since the car was parked and not moving. I reviewed the history on my scanner and noticed that the code is not P0500-00 but P050D-00 Cold Start Rough Idle. Sorry about that.
 
Look through this, did you check pressure after you changed pump?
 
Look through this, did you check pressure after you changed pump?
Yep. The last service center I visited, the one recommended the canister purge valve replacement, did a pressure test for me on the new pump, it is within spec. At the moment my plan is to drop the tank and take a look at the installation that was done since this all started after the pump was changed. Maybe the seal for the pump was not installed correctly or one of the vacuum lines was damaged. Only problem is time and place to do the work. I'll post any results here after this is completed. Thanks! And I did have my scanner hooked up on my way to work so I have a lot of data for a willing shop to analyze.
 
Ok guys I might be in serious trouble here. I called out this so called ASE master mechanic on his work and he went ballistic on me. He degraded me on appearance and my choice of truck and everything you can think of. I hired another mobile mechanic and helped him drop the fuel tank on my tuck, and there was no seal. No seal. The only thing was dirt between the fuel pump housing and the actual fuel tank. I got video. I got pictures. This guy just went crazy threatening me, telling me a lot of things. I got it all on text message. I have everything. But since we replace the seal my truck has no issues at all.
 
Ok guys I might be in serious trouble here. I called out this so called ASE master mechanic on his work and he went ballistic on me. He degraded me on appearance and my choice of truck and everything you can think of. I hired another mobile mechanic and helped him drop the fuel tank on my tuck, and there was no seal. No seal. The only thing was dirt between the fuel pump housing and the actual fuel tank. I got video. I got pictures. This guy just went crazy threatening me, telling me a lot of things. I got it all on text message. I have everything. But since we replace the seal my truck has no issues at all.
I might be in serious danger now.
 
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