Duramax Diesels Forum Truck of the Week
  #1  
Old 03-02-2020, 10:49 PM
SecondGenDura_man SecondGenDura_man is offline
'02 3500 w/Srvc Bed
 
Join Date: Feb 2020
Posts: 1
Default Sending unit questions

Hey everyone. First post after many months of perusing the site for info. Lots of frustrated hours and every inch of fuel line replaced, but I have a few questions that I cant seem to pin down answers to. First off, what is the middle port of the sending unit in the fuel tank for? Is something supposed to be plugged in there? Secondly, is the fuel tank supposed to be air tight? I've had low rail pressure codes since I bought the truck off my old man, and he had them for almost two years. The truck didnt have the power it used to, but still did everything he needed it to. CP3 has been replaced (with a used pump)
Filter head has been rebuilt, all soft lines replaced, and an Edelbrock in line pump (part#17302) installed to give the CP3 a little help. I'm putting everything back together now after replacing all of the fuel lines from the tank to the hard lines next to the glow plug module with reinforced nitrile lines. Any advice would be appreciated.
Reply With Quote
  #2  
Old 03-03-2020, 04:45 AM
TheBac's Avatar
TheBac TheBac is offline
Why do I keep doing this?


 
Join Date: Apr 2008
Location: Mid Michigan
Posts: 13,130

Default

Moved this over to the LB7 section.
IIRC, that second port is deadheaded. Who knows what GM had planned for it.
No, the tank isnt airtight. There should be a vent that runs up thru the fill neck.
What specifically was the low rail code? That could be leaking injectors, bad CP3, etc....

Welcome to DD.
__________________
Tom
"BBT" -- 2003 GMC CC/SB 4x4 [email protected]
"The Cruzer" -- 2014 Chevy Cruze Diesel -- the DD
"Kleshay" -- 2000 C5 Corvette -- the toy

Marlene (Molly) Bacon -- 1936 - 2019 -- RIP Mom You're already missed, at home and on the piano.

Two wrongs dont make a right, but three rights do make a left.
Reality is a matter of perspective.
This forum isn't for the weak of heart.....or wallet.
"Lets build a race car they said. Itll be fun they said. I don't know who "they" are.........but they need a good punch in the face!" -- mufflerguy (yb)
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 11:13 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
vB.Sponsors