Fuel Pump Testing and Fuel Issue Diagnosis (Page 2/3)
theogre MAR 06, 07:36 PM
⚠️ Warning: This jobs can kill you for jacking the car wrong.
see https://web.archive.org/web...ierocave/jacking.htm for highlights


quote
Originally posted by Patrick:
Another tip for dropping the tank... Remove the heat shield that's attached with four(?) screws. It'll make access to the hoses a helluva lot easier.

You have to do that depending on year etc just to remove the hoses before removing any tank hardware.

Can be done by loosening 1 or both top screws & remove both lowers so guard swings away from tank. that makes easier to put screws back w/o aiming the guard too to align the holes.
Patrick MAR 06, 09:50 PM

quote
Originally posted by CSM842M4:

Listen to Patrick, for he is wise. I've done it every time with the shield in place, and wished for more room.



Heh heh... I don't know how wise I am, but after dropping a Fiero gas tank at least half a dozen times, a few time-saving procedures start to sink in.

jelly2m8 MAR 07, 12:57 AM
Everyone here is correct.

from the top side, Disconnect the sending unit connector and feed it down through the bullhead so it hangs down.

from underneath.

7MM remove the heat shield 4 machine bolts

8mm / 5/16" loosen the Fill and filler vent clamps

7/32 ( or is it 1/4?) loosen the 2 pressure feed line clamps, the single return line clamp

Work the Filler and Filler vent hose backwards and off ( hardest part}
Work Pressure feed and return line off


Remove the 4 bolts from the Center support brace mounted transversely under the Fuel tank ( 13 mm bolts)

Remove the nuts from the fuel tank straps ( 13mm deep socket)

Either remove fuel tank straps or bend them back out of the way.

Slide the fuel tank rear ward and work down.

[This message has been edited by jelly2m8 (edited 03-07-2024).]

jumpmonkey MAR 07, 01:25 PM

quote
Originally posted by jelly2m8:

Everyone here is correct.

from the top side, Disconnect the sending unit connector and feed it down through the bullhead so it hangs down.

from underneath.

7MM remove the heat shield 4 machine bolts

8mm / 5/16" loosen the Fill and filler vent clamps

7/32 ( or is it 1/4?) loosen the 2 pressure feed line clamps, the single return line clamp

Work the Filler and Filler vent hose backwards and off ( hardest part}
Work Pressure feed and return line off


Remove the 4 bolts from the Center support brace mounted transversely under the Fuel tank ( 13 mm bolts)

Remove the nuts from the fuel tank straps ( 13mm deep socket)

Either remove fuel tank straps or bend them back out of the way.

Slide the fuel tank rear ward and work down.




jelly2m8, I plan on printing out your instructional and using it as a guide. I'll update this thread with the results.
jumpmonkey MAR 17, 12:09 PM
1985 Fiero GT, jelly2m8, CSM842M4, theogre, and Patrick.

Thank you for all the advice on dropping the tank and diagnosing the fuel pump. I removed the tank yesterday and all I can say is YIKES!

The sending unit and pump are disgusting. I still plan on bench testing the pump today to solidify that it isn't running. Then I'll order a new pump, sending unit, and fuel filter. I also have a fuel additive/cleaner leftover from a service I did at the dealership that I'll use.

Those can be easily replaced but there is something that can't be(at least to my knowledge); the tank. It's bad. Very bad. There isn't just surface rust on the inside. There is enough rust that swinging around the tank makes a sound similar to if it were filled with sand. When I poured out the remaining gas, it was brown like river water.

Is there any way to cut the tank in two and clean it? Possibly line it with a coating? The baffle prevents the tank from being cleaned in a normal way. From what I've seen, getting a new tank isn't possible and finding a clean one is difficult.

Thanks,

------------------
Jumpmonkey

1985 Fiero GT MAR 17, 03:29 PM

quote
Originally posted by jumpmonkey:

1985 Fiero GT, jelly2m8, CSM842M4, theogre, and Patrick.

Thank you for all the advice on dropping the tank and diagnosing the fuel pump. I removed the tank yesterday and all I can say is YIKES!

The sending unit and pump are disgusting. I still plan on bench testing the pump today to solidify that it isn't running. Then I'll order a new pump, sending unit, and fuel filter. I also have a fuel additive/cleaner leftover from a service I did at the dealership that I'll use.

Those can be easily replaced but there is something that can't be(at least to my knowledge); the tank. It's bad. Very bad. There isn't just surface rust on the inside. There is enough rust that swinging around the tank makes a sound similar to if it were filled with sand. When I poured out the remaining gas, it was brown like river water.

Is there any way to cut the tank in two and clean it? Possibly line it with a coating? The baffle prevents the tank from being cleaned in a normal way. From what I've seen, getting a new tank isn't possible and finding a clean one is difficult.

Thanks,




Wow, that is disgusting. Generally I think people who clean their gas tanks use chemical cleaners, fill it up with diesel to get rid of the rust, etc, maybe even some light acids. There are new gas tanks being made every so often, but they are usually in batches with a long wait time, Rodney Dickman does or did make new ones. Other option is to try and find a junkyard Fiero, with a better gas tank. Definitely try chemical cleaners first though.
Patrick MAR 17, 04:21 PM

quote
Originally posted by 1985 Fiero GT:

Other option is to try and find a junkyard Fiero, with a better gas tank.



Maybe there are different rules in different jurisdictions... but out here, the wrecking yards puncture the bottom of every gas tank. I guess it's done to fully drain them. Unfortunately, this procedure certainly cuts down on the number of good used gas tanks for any vehicle around here.
1985 Fiero GT MAR 17, 04:48 PM

quote
Originally posted by Patrick:

Maybe there are different rules in different jurisdictions... but out here, the wrecking yards puncture the bottom of every gas tank. I guess it's done to fully drain them. Unfortunately, this procedure certainly cuts down on the number of good used gas tanks for any vehicle around here.



Interesting, that's unfortunate, I've never visited an actual junkyard, so maybe that's how it's done everywhere, I guess I meant "junk Fiero" not specifically junkyard Fiero, I know someone an hour away from me with 3 or so junk Fieros I can get parts from, so I've never even needed to go to a junkyard!
jumpmonkey MAR 20, 08:05 AM
I found this thread from JohnWPB's build where he cleaned his tank and lined it with fuel tank sealer.
I think that be my best bet. It will take some work to get the inside of the tank clean enough to use the sealer, but it would do the job. The sealer even works on the plastic baffle.
Mike in Sydney MAR 23, 12:32 AM

quote
Originally posted by jumpmonkey:

I found this thread from JohnWPB's build where he cleaned his tank and lined it with fuel tank sealer.
I think that be my best bet. It will take some work to get the inside of the tank clean enough to use the sealer, but it would do the job. The sealer even works on the plastic baffle.



The best way to remove rust from a fuel tank without damaging it is to use the electrolysis method. Google electrolysis rust removal for You Tube videos and instructions. It’s cheap and effective. You may want to do it a couple of times to get all the rust making sure to reposition the tank each time to get the parts you couldn’t get because of the shape of the tank.

After rust removal and rinsing, pour in a couple of quarts (litres) of methylated spirits (denatured spirits) and slosh it around. It will absorb any water left after the rinse process. Use a shop vacuum in reverse to dry the tank before coating. Don’t wait too long to re-coat or it will flash rust. That’s not a deal breaker but the pedantic ones like me prefer to keep rust to a minimum.

After drying, coat the tank. I use Red Kote tank sealer. It’s pricey Down-under but worth every penny. It’s impervious to most petroleum products and ethanol so using anything up to E85 fuel is possible. I’ve used other sealers but ethanol caused them to lift and the rust returned.

For a Fiero tank, you’ll need at least 1 quart of Red Kote. If the tank is likely to have holes or was really rusty, I recommend putting on two coats. It will seal pinholes up to 3mm (1/8”).

I’ve used this method to save motorcycle tanks several times.