scottmoyer

I know this has been discussed a lot and I just bookmarked the page from below on "how to beat the summer heat". I will try this new Tanks VVR valve.

Now, I've had the same issue as many others with the gas boiling. My car is bone stock except for a fuel pump that was replaced in May, 2006. The work order from the shop that did the work only specifies that the fuel pump was replaced and $125 part cost. I've been digging around and trying to find a fix, but haven't. So, I decided to drop the tank and start at the back end and move forward.

Hey look, I dropped the tank the correct way and didn't cut a hole in the car!!



After I got the tank down, I noticed that the top side of the filler neck, at the tank, was covered in gunk. I cleaned it up and found these two pinholes. Is this an issue? I have about half a tank of gas and I tested for leaks by lifting the other side and forcing gas to the neck and didn't see anything, but the gunk tells me that moisture has sat there and the dust accumulation has turned to gunk.



Should I try some sealer on this, or should I replace the tank? It's stamped "84", so I don't think I can get away with the filler neck recall.

I then proceeded to remove the pump and the sending unit. It looks like the pump only was replaced in '06. Since I have this out, should I replace the sending unit with a new one? If so, which one is worth getting? I have no issue buying the best parts needed, but I don't want to waste money unnecessarily. I also noticed that there isn't a pickup sock on my pump. I keep seeing Spectra names online, and Dorman parts are stupid expensive.



Any suggestions or advice is appreciated. Also, I did clean the Fuel Tank Vent Valve, but I don't think it's working correctly. I can blow through the hose into the valve and it pops open for pressure release, but sucking on the hose for air inlet, it barely budges. Thanks

PurelyPMD

iTrader: (3)

Subd.

Evaporust will clean up that tank for you Scott.

scottmoyer

I have another question regarding the Fuel Tank Vent Valve. I took mine apart and thought maybe I reassembled it wrong the last time, but....I'm not sure I understand how it works mechanically. There are the two springs, the larger spring and the smaller one attached to the relief valve. So, when it's all put together, I can blow on the stem and the valve opens to release the pressure. That's the same direction of flow for an over pressurized tank.

If I try sucking in on the stem, I barely get anything through it! Is it designed to allow so little air through it that it's not noticeable? I can place my hand over the top (cap removed) and I can get a vacuum effect if I try hard enough, so I know "some" air is getting thru. What's normal? My valve looks brand new, but I want to make sure its functioning properly. It seems to require too much suction to open that small valve. It also barely opens due to the spring pressure of the small spring. While sucking, if I reach in and push the valve, air flows freely. Thanks for any help.

chazman

iTrader: (4)

Watching.......

Bob88GTA

iTrader: (2)

Scott
I just did my 88. I took it apart and cleaned it all up. On mine, it opens when I put air on the stem. And when suction is applied it opens and allows air to flow. I took a dab of light oil (3in1) and put it on that small valve. It functions pretty easy now....not much suction to open it.
GL

scottmoyer

Does anybody have any insight or suggestions on a quality pump, sending unit? I'm surprised it's so quiet here.

paulo57509

No recommendations for a sending unit, but I've used Denso pumps in my Acura, Safari and Lumina with no issues. They even fit like the originals as well.

As always, YMMV.

I'd look for a pump that comes complete with hoses, clamps, sock, etc.

TTOP350

iTrader: (8)

If the sending unit works properly and isn't rusty, reuse it.

I wonder if there is a vac spec for that valve to open?

Gumby

on a carbed engine an electric pusher in the rear was used to feed block pump and or they went to a big AC car block pump that had a return line.

scottmoyer

Well, I ordered a new Delphi pump, Spectra sending unit, and a Delphi strainer. I pulled my old fuel pump and found that there wasn't a strainer on the pump, so anything in the tank could potentially have been sucked into the pump and caused it to overheat. I also noticed that the bottom of the pump sits in a rubber seat that has an oblong opening (see pic). The bottom of the pump has the fuel inlet as the wide side, but what is the purpose of the narrow side? There is a black plug on the pump. What is it's purpose, as I see many pumps with only a single opening on the bottom for fuel input.

scottmoyer

New question. With the car completely back together, and a full tank of gas, the Spectra sending unit is reading between 3/4 and full on the fuel gauge. Can needle be adjusted on the gauge by removing the needle and resetting it at full? Many newer cars allow for that when you do work on the instrument cluster. I do not want to drop the tank again to bend the float arm, because I wouldn't know how far to bend it to get an accurate reading. I'm hoping there's an external adjustment. Thanks

Bob88GTA

iTrader: (2)

Scott, the needle is gonna be very brittle. You may be able to pop it off evenly and then press back on. I don't think the needle is keyed per say.

TTOP350

iTrader: (8)

Did the stock sending unit not work?
Should always plug them in and run a KeyOn sweep test b4 you put them in the tank.
They are mechanically limited and really can't be bent to change the reading, just made poorly which is why you should keep the original sending unit if its not broken.

Yes the needle can come off the gauge (I have done it) but it'll not quite have the same "feel". Not quit sure why but I'm always second guessing the gauge now to the point I may replace it with a factory calibrated gauge.

scottmoyer

The original sending unit was functional, but since I had the tank out to replace the pump, I wanted to eliminate a potential failure down the road. The original is 30 years old, and with my luck, soon after getting everything back together, it would fail. I like to replace things before they break and cause other problems.

I did have another old gauge that failed, and I pulled the needle off to check it. It's not keyed and will just push back on. I will pull the needle, power the car on and put the needle back on in a slightly above full position.

TTOP350

iTrader: (8)

You need to test that and make sure it goes to empty as well, which is easier to do when its out of the tank.

scottmoyer

I don't like to run any of my cars at less than 1/4 tank. The gauge was reading empty when I went to get gas yesterday, but my fill up was about 11 gallons. My assumptions is that if the gauge reads 7/8 when full and was reading empty, with 1/4 tank of gas, re-aligning the gauge should be fine. Full will read full and if I get to 1/4 tank, I'll get gas as I always do.

Dartht33bagger

What did you end up doing for the gas boiling problem? The Tank VVR valve?

scottmoyer

I still haven't resolved the issue.

chevypower91

hi there. My friend is dealing with the boiling gas in the fuel tank on his ‘88 trans am. Did you find the solution to the boiling gas?
thanks
benny

alan91z28

it might not be venting well... you can do a search in this sub forum on venting and see some options that can help

also running non ethanol gas can help if available in your area if it is good quality, ie we can get 90 octane here in PA which runs well in a stock set up