Last weekend I was headding home from the auto shop when my car started losing power on the highway before it completely gave up. My gas level reading was at 1/4 full. After a tow back to the shop and inspection by a certified mechanic, the judgement call was made on the fuel pump having given up. However, before the repair was done, I recalled the previous owner having said the car would run out of gas at around 1/4 tank full, so I decided to try filling the tank first, before anything was pulled. Gas was poured into the tank the following Monday, and the car started up like nothing had happened. I have an 88GT, and the manual says I have an 11.9 Gal capacity, but when I fill up, only 8.5 Gal goes in. That said, I *know* I have more gas in there, but I'm still running out of juice at the engine somehow. Suggestions were made to me that it could be the fuel pump pickup not reaching the bottom of the tank or a corroded contact area in the fuel gauge itself.

Anyone else experience this problem, and if so, how did you remedy it?

Thanx in advance
--Tj

Welcome to the world of... well... most of us.

Your 88 (like my 87) has a larger tank by about 1 gallon than all the earlier years.

Best thing to do (what I do anyhow) is go more by distance covered than what the gauge says (I just use it as a reference to check my odometer!). When I'm at about 350km's in the city - it's time to hit the pumps NOW.

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87/88 V6 5spd Notchback Hybrid (coming very soon - Fastback conversion into a "FormulaGT")

My page: http://www.fieroclub.com

Like he said-welcome to the strange world of Fieros. Our 84 started doing the same thing about 3 years ago, then, after changing the FP last winter, it will now run even with less than 1/4 tank. Try to keep it at 1/2 tank or more to keep plenty of fuel on the pump. That's what keeps it cool.

Funny thing was-when I changed the fuel pump, I found the 2" long line on the pressure side, inside the tank, had deteriorated. Wonder if the higher level of fuel kept it from leaking as bad, and then when it dropped down to 1/4, it leaked too badly to keep it running?

with a full tank [realy full this takes several click off of the service stations pump]
NOW IS THE POINTER ON FULL???
or way over past the "F" line???
if it is past the line
it will not read "E" ever!!!
so index it by

pulling off the glass/plastic cover on the fuel gauage [4 torks screws]
and grab the center hub of the gas/fuel guauge pointer and pull it off
line the pointer exactly on "F"
and press it back on
now it is indexed
and just may read near "E" now!!

BTW DO NOT EVER run a fiero totaly out of gas
the fuel pump needs gas to cool it or the pump will fail awile later

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Question wonder and be wierd
are you kind?

I do like watts does, I go by My odometer as My fuel guage doesn't work. I don't consider dropping the tank to replace guage sending unit VS odometer reading to be worth the time,$$, and unexpected horrors I'm sure I would come across while trying to make My gas guage work. My 86SE-4sp is a daily driver, I only fix what I need to keep it running and safety issues.

I did what ray b said in reverse.
When I had accidently run out of gas, I set the pointer to "E".

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Dangerkitty "on the prowl"
Maroon 87 GT automatic, loaded, now with "sparkle wheels"

quote Originally posted by max1: I do like watts does, I go by My odometer as My fuel guage doesn't work. I don't consider dropping the tank to replace guage sending unit VS odometer reading to be worth the time,$$, and unexpected horrors I'm sure I would come across while trying to make My gas guage work. My 86SE-4sp is a daily driver, I only fix what I need to keep it running and safety issues.

I'm with Max1 on this one. I just can't work up the motivation to drop the tank to have an accurate fuel gauge. It would be nice, but it can wait until the pump needs changed or something else that requires dropping the tank. Until then, the odometer is my fuel gauge.

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Brad
86 GT 5 speed
Aren't all Fieros project cars?

Check under the car for damage to the tank. A friend of mine bought an 86 GT that had the same problem. He found that the previous owner had backed over a rock and dented the tank enough to hold the fuel gauge at 1/4 tank and reduce the volume of the tank.

ok, my ********* (insert word) computer just decided to kill the net connection and delete my entire post before I could post it. here's my best attempt at redoing it

watts, max1, GT86: good suggestion! only problem with that one is... my lead foot... sometimes I have it, sometimes I don't, so my milage varies greatly between tank-fulls. again, good suggestion, though.

maryjane: I'm a little confused... do you mean that after replacing the fuel pump the needle is closer to F when it runs dry now? or did replacing the fuel pump fix the problem? this is what I'm considering, if it will help.

ray b, DangerKitty: will this mess with readings from the tank if I get a new pump? as much as possible I want to avoid this type of alteration.

BlueGT4 Me: last time I was under there, I didn't see any damage on the tank, but I'll check again next time the car's on the rack.

Thanks for all the suggestions and help! "+"s all around.

I would like to fix this as much as possible, though, since I want to make this car something special (V8!! V8!! V8!!). I guess this problem isn't isolated, since so many people replied . Are there any aftermarket solutions to this? Perhaps something out of a Summit catalog?

Thanks again

There IS a fix, but it involves dropping the tank and recalibrating the float assembly to read exactly full when full and empty when empty. Replacement of the fuel pump should not effect the gauge reading since the pump itself has nothing to do with the sending unit (however the pump is mounted to the sending unit).

Dangerkitty has a good suggestion with calibrating the needle to empty rather than full, however I would probably go a bit below "E" so when the needle is pointing at the "E" you hopefully still have enough gas to get to a station.

In the meantime perhaps since you know you've run out of gas at the 1/4 mark in the past, maybe it would be a good idea to fill up at say 1/3. Like mommy always say's "it's better to be safe than sorry!"

"I have an 88GT..."

Yep. Same thing here. I have an 88 Formula, and found out that "1/4 tank = E" the hard way as well...

:P

quote Originally posted by tjfennel: maryjane: I'm a little confused... do you mean that after replacing the fuel pump the needle is closer to F when it runs dry now? or did replacing the fuel pump fix the problem? this is what I'm considering, if it will help ray b, DangerKitty: will this mess with readings from the tank if I get a new pump? as much as possible I want to avoid this type of alteration. Thanks again

you are just correcting the pointers position
as the tank can ONLY be FULL not over FULL
so the pump should have no-thing to do with the guauge, but if after the pumpswap it reads over the "F" line just re-do it, to read exactly on "F"
if it reads hi on the "F" end it never will read "E"

BTW a new sender is only sold by GM as a unit with a new pump and all wires and other in tank bits [like it comes out] at the outragiously high price of about $500
so if you need a new sender [rare] go to a junkyard

but try the pointer move first it's cheap [free] and alot eaxyer than droping the tank

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Question wonder and be wierd
are you kind?

The point is why do we run out at 8.5 gallons instead of 10? I have never put more than 8.5 gallons in my car without overflowing the neck.
When I had my tank out there was a gap between the bottom of the pump screen and the bottom of the tank. It my be a good idea to mount a pickup on the bottom of the tank then run a hose to the pump.
If I was going to do something like that I think I would replace the pump with an aftermarket line pump.

You may find an article ( http://www.fieropride.com/tech/gas_guage.htm ) from Ray Paulk interesting... It helped fix mine. Good luck...

[This message has been edited by Panama Jack (edited 07-20-2003).]

862M4inCA: yeah, you're right... that's what I've been doing, too. I never wanna be stranded in the middle of traffic again.

ray b: ouch... quite pricey. the needle move is sounding a bit more appetizing now, but I'm still confused as to why I'm only filling up 8.5 gallons and still running dry...

Jake_Dragon: ok, not so confused now. I think this point is the part that baffles me the most. I could do the meter recalibration, but that probably won't fix the fact that I'm running dry with gas still in the tank.

Panama Jack: thanks for the link! this will definetly help some.

Thanks again for the help. More +s!

quote Originally posted by tjfennel: I never wanna be stranded in the middle of traffic again. ray b: ouch... quite pricey. the needle move is sounding a bit more appetizing now, but I'm still confused as to why I'm only filling up 8.5 gallons and still running dry...

8.5 gals thats why I said many click offs of the pump at the gas station
it helps to wait 30 seconds or more between trys too to sqeaze in all the gas you can just to be sure it is realy full

there may be a little left in the bottom but mostly it is not getting full to the top thats why it only takes 8.5 gals

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Question wonder and be wierd
are you kind?

quote Originally posted by tjfennel: maryjane: I'm a little confused... do you mean that after replacing the fuel pump the needle is closer to F when it runs dry now? or did replacing the fuel pump fix the problem? this is what I'm considering, if it will help. Thanks again

No- now the gage reads exactly as it should.
I haaven't run out of gas since changing the pump, but I have run it almost empty and it took 9.5 gal to fill it. I did nothing to the sending unit while I had it out, nor did I rcalibrate the gage.

When I pulled the pump/sending unit, I noticed immediatly that gas was leaking around the 2" hose directly above the pump outlet. The hose was still all there & connected on both ends, but it had become soft & porous. Here is what I think was happening:
As long as there was plenty of liquid in the tank, the hose leaked very little, & the fuel made it's way on up to the filter & tbi. Once the fuel level dropped below the rubber hose, there was no pressure from surrounding gas to hold the liquid in the hose, so it all went out the porous hose into the tank instead of up the line. (To illustrate-Blow thru a straw in the air, then blow thru the same straw immersed in a couple inches of liquid. Feel the increase in pressure required to blow thru the straw?) Granted, upon a pressure test, I was only getting 6psi of fuel press instead of 13psi as called for, but it was enough to run the engine, except on hard acceleration. That's why I dropped the tank & pulled the pump. I went ahead & changed the pump, tho I believe the hose is why I had low fuel pressure, & why I ran out of gas when it reached 1/4 tank. This was on a 4cyl BTW. I used clamps on the new install too. It may not be the problem in your case, but I believe it was in mine.

ray b: ok, I'll give that a try next time I fill up

maryjane: that actually sounds like something that may be happening on my car, though I don't run out of juice under hard acceleration. I'll see if I can get the pressure tested, and if there's low pressure, a tank drop is going to happen very soon.

thanks for the suggestions! will give those a check.

Ohh another member of the Fiero walk club. welcome, I had the same problem, Just calibrated my needle by pulling it off pushingit on.

quote Originally posted by ray b: 8.5 gals thats why I said many click offs of the pump at the gas station it helps to wait 30 seconds or more between trys too to sqeaze in all the gas you can just to be sure it is realy full there may be a little left in the bottom but mostly it is not getting full to the top thats why it only takes 8.5 gals

Just a note of caution.....topping off a fuel tank can be a very bad thing. The pumps are designed to shut off for a reason. The reason being that topping off a fuel tank can result in raw fuel being drawn through the fuel lines going to the carbon canister and saturating the carbon requiring replacement.

As for the 8.5 gallon deal....you need to keep in mind that the rated fill capacity of a fuel tank is total and complete fillup from bone dry. Picture your tank as a spray bottle. When the level of liquid in the bottle gets low enough, the pickup tube for the sprayer can't reach the rest of the liquid (in most bottles, not all). This doesn't mean there isn't any left, just that the level has dropped beyond the capability of the pickup tube. This is likely the same thing thats occuring in the fuel tank. The fuel level is too low for the pickup to effectively draw fuel.

I was another member of this not so exclusive club. I re-referenced the needle. no problem.

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American Exotic
Owner since December 6, 2002, 1st Fiero

When you do the pressure test, don't forget to do the return line pinch test. PSI should increase-on mine, it actually fell off a couple of psi.

quote Originally posted by linenoise: Ohh another member of the Fiero walk club.

quote Originally posted by RACE: I was another member of this not so exclusive club.

lol... I hope I'm not a frequently-visiting member.

quote Originally posted by 862M4inCA: Just a note of caution.....topping off a fuel tank can be a very bad thing. As for the 8.5 gallon deal....you need to keep in mind that the rated fill capacity of a fuel tank is total and complete fillup from bone dry.

I always avoided topping off so I wouldn't get spills like I used to see at the gas station I worked at. I didn't know it had any adverse effects on the carbon canister.

Note: 8.5 gallons is my typical fill up at 1/4 tank, when I experienced the engine stall. I'm not sure how much went in when I filled it up after the stall, since I had used a gas can and about 5.5 gallons or so went in after the can, so I'm not exactly sure if 2.4 gallons was what remained in the tank after the stall. Still, I know I ran out at 1/4 tank, so something's wrong for sure.

The spray bottle example made sense, though. I'm sure it doesn't help when the gas is sloshing around in the tank, too.

quote Originally posted by maryjane: When you do the pressure test, don't forget to do the return line pinch test. PSI should increase-on mine, it actually fell off a couple of psi.

I'll make note of that for when I do the repair. I just picked up one of those Fiero factory manuals from the Fiero Store, and I found the diagram of the pump/sensor assembly. Recalibrating the needle itself is sounding more appealing now, but I've noticed that when I fill up, the needle isn't much over F. I'm worried that if I do recalibrate the needle that I'll just be closer to E, but not quite there and just may cause more confusion with how much gas I have left, since the true E point will have moved, but not quite down to E.

Thanks once more for all the replies! Hopefully this will be remedied soon, I don't wanna run out of gas in the middle of the country at 3am.

Well? Did you fix it? I have the same problem and would like to know

GP

Well I must be the only odd one with a Fiero that has an accurate gas gauge.

I ran it to E (1/8 tank) twice without a lick of trouble. No moans from the fuel pump and no signs of starvation.

I didn't run it that low on purpose, just ended up there.

I don't run it under a 1/4 any longer just to be on the safe side and not put strain on the fuel pump.

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quote Originally posted by gpierce: Well? Did you fix it? I have the same problem and would like to know GP

No, not yet. I ran out of cash Figures, huh? I have this discussion bookmarked, so when I fix it (probably going to replace the fuel pump rather than fiddle with the gauge), I'll put my results up here.

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Red '88 Fiero GT -- 2.8V6, 5Speed

I suppose it hasn't occurred to anyone here to do as I do and keep a one-gallon can of gas in the front compartment...?

I only put about 3/4-gallon in it (to allow for expansion on hot days), and before anyone (else) tries to tell me, "But it'll BLOW UP!!", I've been doing it for ten years without a single mishap (knock on wood).

Once in a while I forget that the gauge isn't 100% accurate and I run out of gas on the way to the gas station, but it eases my mind by an immeasurable amount to know that I have another 25 miles sitting right there in the front compartment to use whenever I need it.

Oh, and I did the 'pop the needle off the gauge and reset it' trick... it helps, but is not perfect. (BTW - use two spoons, bottom of the 'bowl' against the face of the gauge, tip of the spoon under the center section of the needle, prying the needle off the shaft so it comes off straight... it's scary at first because it feels like you're going to break something, but I was pleasantly surprised.)

EDIT - typos

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Patrick W. Heinske -- LZeitgeist@aol.com -- 1988 Red Fiero Formula
- 1st Place - Stock Coupe - FOCOSEVA 2000
- 3rd Place - Stock Formula - FOCOA Nat'l 2001
- Class Winner - 1982 to Present - Tarheel Tigers All-Pontiac Show 2001
- Class Winner - Fiero: All Years - Tarheel Tigers All-Pontiac Show 2002
(working on an Automoda convertible conversion...)

[This message has been edited by LZeitgeist (edited 08-13-2003).]

quote Originally posted by tjfennel: No, not yet. I ran out of cash Figures, huh? I have this discussion bookmarked, so when I fix it (probably going to replace the fuel pump rather than fiddle with the gauge), I'll put my results up here.

Replacing the fuel pump is NOT going to fix your gauge problem. So save yourself some money and either do one of the two other things suggested above...Recalibrate the needle or sending unit, or carry a 1 gallon gas can as backup.( Or is that 3...?? )
The fuel pump has nothing to do with the gas gauge reading whatsoever. The only thing they have in common is the wiring harness, and that's only because they are in the same location.
The problem is the sending unit. So you are either gonna have to recalibrate the needle or the sending unit. Recalibrating the needle is more that just "4" torx screws. You have the take the pod completly apart and then plug it back into the harness and turn your key on to make sure you have it moved to the 'correct' position. This is by far alot easier than a tank drop and recalibrating the float/sender assembly ( I have done both.. )

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'85 SE - '86 Fastback SE - '99 Chevy K-1500 Z-71 - '00 HD 1200XL Sportster

Wouldn't it be nice if there was a access panel in the console to get at the fuel pump

Steve

quote Originally posted by spearce: Wouldn't it be nice if there was a access panel in the console to get at the fuel pump Steve

It would have to be a long one that went all the way to the firewall as the sending unit has hardlines that reach to the back end of the tank and it would be impossible to take the unit out without that. Of course a person could modify the lines so they disconnect
at the sending unit top.

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You will not ever get the entire tankfull out of any car. A gallon or 2 laying on the bottom of the tank will only be like maybe 1/2" deep or so. The pickup will not pick it up. The only way to make it do that is make the pump set in a part of the tank made lower than the rest. Factory likes to stamp flat sheet metal better than intricate shapes.

quote Originally posted by Jake_Dragon: The point is why do we run out at 8.5 gallons instead of 10? I have never put more than 8.5 gallons in my car without overflowing the neck. When I had my tank out there was a gap between the bottom of the pump screen and the bottom of the tank. It my be a good idea to mount a pickup on the bottom of the tank then run a hose to the pump. If I was going to do something like that I think I would replace the pump with an aftermarket line pump.

TJ - like yourself, soon after buying my 87GT I found that I would hear the ominous fuel pump 'running empty whir' from inside the pass compartment, and some weird running problems round corners and such when hitting below 1/4 tank. I ran some Fuel system cleaner and since then i always fill up at 1/4 tank - takes about the same as you, 8 to 9 gallons to fill-er-up

Kim

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You can check the resistance of the sending unit with a multimeter without dropping the tank by unplugging wires in the engine bay.
It's should be 90 ohms full and 0 ohms empty. My one bad experience with fuel indication was that gauge only showed 1/4 when full. Turned out that it was the gauge in the instrument panel not the sending unit.

I had a similar problem on my 87 until I pulled the tank out and replaced the filter/screen on the bottom of the pump with a new one. After that I can run it down to empty and have put in as much as 10.5 gallons.
On my 84 I also had the problem of the rotting fuel connection line above the pump. I got tired of replacing it and found a metal connector out of a V6 gas tank and that has worked for 6+ years now.

Well, I haven't pulled anything yet, which is a good thing because there seems to be a lot of conflicting opinions/experiences here about the hows and whys of this problem.

Cheapest alternative so far is pull the needle and reposition it. Though I *may* decide to do this in the near future, I want to find a solution to this problem, not a cosmetic fix.

Since I have access to a lift and some mechanic help, I can do the repair myself with the only cost factor being the parts themselves. Recalibration of the (sending?) unit in the tank seems like what I'll need to do, but the mechanic who started up my car when the tank ran dry said he thought the pump sounded odd, and the car's idle does sound erratic.

If I can find a small gas can that will fit nicely in the passenger compartment, I'll pick it up and keep that in the car for emergencies.

Anywho, like I said in an earlier post, I'm gonna do something eventually, and I don't think I'll just do the needle repositioning. Regardless of the cost efficiency or the ease of the procedure, it won't sit well with me, knowing that something else is wrong somewhere, and I'm just doing the most cosmetically easy thing to fix it. Again, I'll post info on what happens with it when I do it.

Kim, if and when I do go in "inspect" the tank and stuff, wanna come and see what's involved? Dunno when this'll happen, though. I don't have cash to put into her right now.

Ah, one more thing. 87convert, when you say you had the same problem with the gauge, do you mean that replacing the filter/screen thing allowed the needle to go down to E without repositioning it? Though this may not be the case, I wanna check everything suggested in this thread before I make a final decision on what I'll do.

Thanks

Yes, it's a 1-gallon red plastic container - I picked it up for a few bucks at a gas station/convenience store.

TJ, I ran some Chevron Fuel System Cleaner stuff. Who know if it actually does anything, but I figure can't hurt on an old car like ours

What I meant to say is that my problem turned out not to be a problem with the gage but rather a problem of not being able to use the last 1.5 to 2 gallons in the tank. After changing the in tank filter/screen, I am now able to use all of the fuel in the tank and the gage does in fact go down to E when the tank is empty.

quote Originally posted by 87convert: What I meant to say is that my problem turned out not to be a problem with the gage but rather a problem of not being able to use the last 1.5 to 2 gallons in the tank. After changing the in tank filter/screen, I am now able to use all of the fuel in the tank and the gage does in fact go down to E when the tank is empty.

Ditto. The old fuel pump would start sucking air around 1/4 tank. Since I replace it, I have been able to fill the tank up with as much as 11.2 gallons in my 87. That said, it is not good on the fuel pump to run it that low. As stated earlier, the fuel cools the pump. Good to refill at 1/4 tank or more. The plus side is the 3800 gets better mileage than the old 2.8. I regularly get 23mpg city driving. I haven't gotten it out on the highway yet, but I expect around 30 at REASONABLE speeds.

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