'86 Burb fuel issues

[suburble]

Hi all-

Been a long time, but I'm getting a start tomorrow on my '86 Burb. I'll be starting a refresh of the fuel system from the tank on up to the pump.

I put a new carb and pump on about a year ago and still failed emissions for high NOx readings, IIRC . After some troubleshooting I found out I was having intermittent fuel pressure problems. Due to Life, I've let the 'Burb sit for almost a year, only starting it up for brief trips to the end of the driveway.

I'm getting started this weekend on dropping the tank, replacing the sender and in-tank filter, and replacing all rubber hoses between the tank and motor.

Does anyone have any tips or tricks for:

1. Dropping a full 31 gallon tank on a 'Burb
2. Replacing all soft lines- are there any that won't be obvious?
3. wiring in an air/fuel ratio gauge? (already had one)

Thanks,
-Josh

 

[smoothandlow84]

1) drain the tank of al the fuel you can. You can purchase an inexpensive manual or drill poewered pump from Harbor Freight for under $20.
2) use a floor jack and prop in under the nearly empty tank to assist in lowering it down to the ground
3) If height is an issue, use elevate the truck high enough to drop the tank and use jack stands to secure the frame of the truck.
4) clean the top of the tank where the locking rings hold the pump/sending unit in place. Ears of travel cause a lot of dirt and grime to collect up on the top of the tank. I used a shp vac/air blower nozzle to cleN off the debris on both of my squarbody pickup tanks (I had to drop and replace two fuel pumps and sending units last month).

 

[skysurfer]

Agree with everything S&L said. A minor issue I had was I couldn't reach one of the hose clamps on the rubber fill hose so it had to come down with the tank. The hose hangs over the frame rail a little bit so as you drop the tank it gets tilted and thrown off balance by the hose. Not much of a problem with the five gallons of fuel I had but there's no way I would have tried it with a full tank. Draining the tank will take about 200 lbs of trouble out of the job.

 

[bucket]

I want to know why someone in '86 ordered a 454 Suburban and didn't order the 40 gallon fuel tank.

I also recommend pulling out as much fuel as you can. Twice I've had to drop the 40 gallon tank out of my Burb when it still had over 20 gallons sloshing around in it. That was no picnic.

 

[smoothandlow84]

Keep a fire extinguisher close by as well. Its It's always a good idea to have one while working around fuel. Well worth the $20.....instead of burning down the garage.

 

[Georgeb]

While we are on the subject of safety. When you go to drain the tank I would suggest you use a primer bulb for an outbuard motor and let it syphon drain rather than use a drill pump. An electric drill motor has open brushes that are an open source of ignition should you have a spill or a high concentration of fumes.

 

[suburble]

I want to know why someone in '86 ordered a 454 Suburban and didn't order the 40 gallon fuel tank.

I also recommend pulling out as much fuel as you can. Twice I've had to drop the 40 gallon tank out of my Burb when it still had over 20 gallons sloshing around in it. That was no picnic.

I'll be darned. I'd been assuming it was the 31-gallon tank because they told me at Autozone it should have a 17, 22 or 31 (if I remember), according to the computer, and I knew it took a lot more than 22 gallons. Just looked at the glovebox sticker and it does actually have the 40 gallon.

Does the 40 use the same pickup and sender as the 31, or did I order the wrong parts?

Edit- NVM, looked it up, Dorman 692-093 should fit either one.

Thanks,
-Josh

 

[austinado16]

hijack

Hold the phone......there's 40 gallon available!? What models was that offered in and what's the RPO code? I've always thought mine was 34ish, and I've crammed 35 and change in it prior to long trips. The extra 5+ gallons would be pretty since our rig is only used for road trips.

/hijack

 

[bucket]

hijack

Hold the phone......there's 40 gallon available!? What models was that offered in and what's the RPO code? I've always thought mine was 34ish, and I've crammed 35 and change in it prior to long trips. The extra 5+ gallons would be pretty since our rig is only used for road trips.

/hijack

Sounds like you got the 40. When all of mine have been showing down close to the empty mark, there's still around 8-10 gallons in there. Now in my K5's with the 31 gallon tank (same as base tank in Burbs), empty means empty.

 

[austinado16]

When mine hits the empty, we're walking.....literally. From there, it'll take about 35 gallons if I keep adding fuel after filler nozzle automatically kicks off.

Other than comparing dimensions to what's listed for new tanks on places like autopartswharehouse dot com, is there an RPO code I can look for?

 

[bucket]

When mine hits the empty, we're walking.....literally. From there, it'll take about 35 gallons if I keep adding fuel after filler nozzle automatically kicks off.

Other than comparing dimensions to what's listed for new tanks on places like autopartswharehouse dot com, is there an RPO code I can look for?

I don't know off hand what the RPO is, it's likely in the library though. Basically, if you run it down to empty, you still have 5 gallons in there

 

[bucket]

Looks like NE2 is the rpo for the 40 gallon tank.


Also, I wasn't sure the 40 gallon tank took the same sender as the 31. But after thinking about it, that may be correct. IIRC, the 31 gal tank is deeper than the 25. Then the 40 gal is the same depth, but the tank is longer than the 25/31.

 

[austinado16]

Thanks for looking up the RPO code. Do you have a link to where they all are in the library?

Just checked my RPO sticker, and there's no NE2, so it looks like I could upgrade to a 40.

Next question....will a 40 fit inside the big skid plate that covers the bottom of the tank on the 4x4 models like mine?

 

[bucket]

Thanks for looking up the RPO code. Do you have a link to where they all are in the library?

Just checked my RPO sticker, and there's no NE2, so it looks like I could upgrade to a 40.

Next question....will a 40 fit inside the big skid plate that covers the bottom of the tank on the 4x4 models like mine?

If you were able to put 35 gallons in, you already have the 40 gallon tank. There was no 35 gallon tank available. The 40 gallon tank may very well have been standard equipment by '90, so your SPID would not show an RPO for it.

And I know that the 40 gallon tank was usually optional, but I cannot remember ever seeing a Suburban that did not have it. Gas was cheap, and it was probably only a 10 or 15 dollar option.

 

[bucket]

And if you do happen to have the 31 gallon tank, no, the 40 will not fit in the stock skid plate.