v1 rot8

98 C5, 100,000mi. I ran out of gas today with over 1/4 - 3/8 showing on the gage. Have been using Techron plus Chevron fuel. It took only about 12 gallons to fill it up and I should have a 19 gal tank according to the manual. So shouldn't I have had about what the gage was showing, 5- 7 gals? I don't understand why I ran out of gas. Anyone got any ideals on this situation?

JMc

Yeah, it sounds like your fuel sensors are screwed up. Most I've ever been able to fill my C5 with is about 16 gallons. I don't know if '98's had higher capacity gas tanks than my '02.

v1 rot8

I think there is a problem with the sensors as well, but do not understand why I could not put anymore then 12 gallons back in. I re checked my owners manual and it says 19 gal tank. I was wondering if maybe there is some problem that is keeping me from getting the last 5-7 gallons out of the tanks.

SCM_Crash

Put some techron in... Do it for a couple of fill ups. Techron helps get rid of sulfur build ups that cause the fuel sending units to read wrong.

Choreo

I am sure your sensors are probably shot like most of us by now - mine are no longer responding to Techron/Seafoam, my gauge is worthless - I just go by total miles since last fillup, but if you ran out and it only took 12 gallons, you have other problems besides sensors.

It is really stunning that a 3rd party has not solved this sensor issue with a replacement that will work with the crappy gas out there. I know that not every car on the road is running without a gauge and they have the same crappy gas!

DeeGee

You're spot on; the capacity of the right and left tanks is about 18+ gallons. If you're only putting 12 gallons in then its not your sensor. You really do have 1/4 tank remaining. Some of the fuel is not transferring from the right tank so you're running out with fuel remaining in the tank.

I've seen this before so I'll dig into my archive and see what I can find.

RedRiderZR1

I agree. If you ran out of gas and can only put in 12 gallons, then you do have another issue other than bad senders. Mine ran out of gas once when it said 1/4 of a tank once. But i was able to put over 18 gallons in it. But if you can only put 12 in, Something else seems off.

DeeGee

Take a read of this one. I suspect this is your problem:

http://forums.corvetteforum.com/c5-t...m-failure.html

Its a lot of very interesting reading but the answer is in Post #36

It was a plugged orifice in the jet pump assembly.

Looks like you can pull the pump without dropping the tanks.

v1 rot8

Thanks DeeGee. I feel this is what my problem is. I looked thru the service manual this morning and found out about the jet pump and how it works. Strange for jet pumps to go bad but I am feel certain that is probably the problem. We have been using jets pumps in fuel tanks in jets for years and I have never heard of one not working. I will burn the gas down some, drain the rest and pull it out. Thanks

Vetteman Jack

Good info and thanks DeeGee. I'll keep this on file in case this ever happens to mine.

DeeGee

, hope it works.

madmatt9471

Use some Sea Foam in the tank and that will loosen any debris that is hindering the reading - follow the directions on the can!

The stuff works wonders

Thanks,Matt

v1 rot8

Thanks for the feed back boys and girls. After looking thru the vette manual on how the system works plus the link DeeGee sent I feel certain I have either a clogged jet pump or fuel line back to the right side. There are two fuel tanks as we all know, one fuel pump in the left tank that feeds the engine plus the jet pump in the right tank. The right tank jet pump pumps fuel to the left tank. They should keep pretty close to level with each other. If the Jet pump is not working properly or the fuel line is partially clogged then the fuel is not staying level. This inbalance may be some of the fuel gage read problems so many of us have. If the sides are not close to level I believe you will get the fuel gage problem. I got a full tank now so I will burn it down over the next month, then pull the right side out and clean it up and see if it helps. Will get back to you all if it fixes the problem.

Dominic Toretto

DeeGee FTW

-Alex

dobewillie

Good luck with your problem

Choreo

That may be because if it clogs in a jet there is nothing left to diagnose!

DeeGee

I'd still be thinking jet pump rather than crossover lines. Take a look at these pics. The top one is the Evap pipe; the bottom (5) is the crossover hose. Those are pretty large bore lines to clog up, particularly as we know that sulfur contamination/build up is the cause of the problems on the fuel gauge sensor. That would be a lot of sulfur particularly if you've given it a shot of Techron.

v1 rot8

you certainly have a point there Choreo

v1 rot8

Yes, you are right Deegee, that would take a big clog for the lines wouldn't it. I am going to focus on the Jet Pump when I pull it out, it operates with a very small hole

Swampxray

had the same thing happen to me in my 2000 coupe. The jet or transfer pump failed...had a full right side tank and nada going across. When the dealer pulled the right tank they found it had been significantly deformed due to heat from the exhaust. Appealed to GM for a hidden defect warranty claim and they came through, covered the cost completely. Whew!!!...

Good luck on the fix.