[Coloradopaul]

Hey everyone,


Just noticed today that I have a raw fuel odor emanating from between the cab and the bed on the driver side of my 2004 Colorado Extended cab Z71 4x4. I assume the fuel sending unit is leaking especially since I filled the tank up the day before. I have been having a minor starting issue first thing in the mornings so maybe that is related. Getting ready to shop for sending units. What do you guys recommend as a replacement? From what I have read, not all of them are created equal. AC Delco makes theirs differently than Delphi. The guide rod springs are on the inside of the tube to protect the pump wires. The pump motor is a 10 vane as compared to an 8 vane. Also where can you get a fuel tank if the ring on it is rusted bad? This truck has always been garage kept in it 184,000 mile life. Have always made sure to spray off dirt and salt especially on the tank. I did replace a sending unit on a Chevrolet Cheyenne years ago that wasn't too bad. Welcome any suggestions.


Thanks


Paul
kc8ddq@aol.com
614-354-8697 cell

 

[Coloradopaul]

Thanks for the information. I have a backup tank from a salvage yard ready just in case the locking ring tangs are worse on mine. I did clean off the loose rust and paint it with Chassis Saver. I'm hoping mine is in better shape since I have kept the truck garaged all these years and always flush of the top of the tank area when the truck is washed. I remember when I replaced a sending unit on a 1990 Chevy Cheyenne and it was rusted severely so I have always kept the top of the tank fairly clear of dirt and debris. I figured I would go ahead and replace the entire pump/sending unit assembly anyways due to age. I also have problems with my fuel pressure bleeding off over night. Was told that is probably a faulty check ball in the sending unit. So it is probably on borrowed time anyways.


Thanks
Paul

 

[Coloradopaul]

PS. I will try to post pics or info on what I find. Will be doing it this weekend (8/12/16).


Paul

 

[Coloradopaul]

Ok. Got the sending unit/fuel pump replaced. Pretty easy to drop the tank. No issues encountered except for the rusted locking tabs on the tank itself. I cleaned all the loose rust off and sealed it with Chassis Saver. Seemed to be no worse or better than the tank I got from the salvage yard to have just in case. In my opinion, I would think that it is much easier to drop the tank as opposed to lifting the bed. Would love to know how to post some pics but have never done that. If anyone needs pics, contact me at kc8ddqataoldotcom.

 

[Coloradopaul]

Tank pics

Here are some pics.


Paul

 

[Coloradopaul]

I'll check out Photobucket. You are right in being able to check the fuel system by taking the bed off. Didn't think of it that way. I uploaded some pics last night of the before and after the cleaning and rust sealer. The thumbnails are in post #6. Now getting a PO455 which indicates an issue with the canister vent solenoid valve. Will be checking into that when I get home this afternoon. If there is fuel in the canister, can I just take it off and drain it out? I did "top off" the tank prior to all this starting.


Thanks


Paul

 

[Coloradopaul]

The sending unit/pump and pressure sensor was all new and Delco OEM. I pulled the canister/ vent valve solenoid and tested the solenoid. It operated with 13.8 volts applied to the pins. Reassembled everything, reset the codes, and unplugged the battery for 10 min or so. After that, I took it for a lengthly spin to get everything up to operating temp. No codes were set as of yet. May have to drop the tank again this weekend and double check fittings, orings, and electrical connections to make sure everything went back together OK. I did coat all the fitting orings, mating surfaces, and connector seals with a light coat of silicone grease so things would slide back in place easier. I'll se what develops tomorrow. I appreciate all the opinions and expertise that you all have provided.


PAul

 

[Coloradopaul]

I'm pretty sure that I connected it till it clicked. What is the possibility that the fuel cap has failed? Yesterday there was a message on the DIC that said "fuel cap". I checked it and it seemed tight. Was thinking about picking up a new one from the dealer tonight.