Hello,
I have a question about the operation of the fuel pump.

My car was low on gas (no suprise there) and I pullled in for quick $10. I get in the car, turn the key, heard a weird unusual click and the car wouldnt start. Crank crank crank crank ... no start. I pushed it off to the side and there was no fuel in the fuel rail (via the schrader). I walked 3 miles, got some wire, books, etc ... went back and it started right up.

So, 10 years ago the fuel gage was "right on". I could have "one tick" and drive 10 more miles. But recently, over the last 3/4/5 years I started to run out of gas with one tick ... 2, 3; now even today with it showing a quarter tank. So, for some reason the fuel gage is not dialed in. If someone knows how to dial it in, I'd like to know how to do that. But, he question is, since the fuel pump sits in the tank and is cooled by the fuel in the tank and running through it, and if the car is "running on fumes", whether the fuel pump can heat up and either FAIL HARD or FAIL INTERMITTANT ... meaning get hot enough to not run and then given 3/4 hours of cool down, just start working again. The other question is whether the fuel pump after getting hot, lost some reliability and will fail hard at some point sooner than later. So, wondering if I should put a new fuel pump in before that happens.

 

I would, and yours is older than mine.

I'm going through this now. I've come to the conclusion just to replace the whole thing. The pump is mounted on the sending unit. The float arm and resistor/rheostat is, too. Just get the whole thing. Replace the fuel filter and pressure regulator while the system is shut off.

ZipCorvette--$329
Volunteer Vette--?
Corvette Central--$319
Just a few.

Mike
'90 'vert

 

If it was me, I would replace the pump. I had a pump fail 130 miles from home. The cost of towing outweighs the cost of a pump. I just ordered a new Walbro pump from Racetronix. They have a C4 kit that includes pump, gasket, screen and wiring adapter for $110 (basically everything you need. It's a 1 hour job to replace.

Before the pump went, I was getting stumbling under 1/4 tank. But that may be common.

 

Or if you want the best price on the whole sending unit get this at Corvette Recyclers. I promise you can't beat this price if you need the whole sending unit.Then add one of the Walbro 190 gph pumps....WW

http://www.corvetterecycling.com/198...p/25027510.htm

 

Thanks guys for the replies.

Yeah ... I've had the car 18 years. I replaced the pump 4 times. I know what you about the stumble. Mine was doing the same thing when I was on a cloverleaf in town. I bet there was less than 1 gallon in the tank even though it showed 1/4.

Today, I drove around and the gage showed there was a 1/2 a tank. Thats my problem. I put 3.5 gallons in yesterday. Its pretty funny that it wouldn't start AFTER I put the gas in. You would think it would run out BEFORE I got to the gas station.

I would really like to get the fuel gage dialed in. For the last couple of years, after filling it up, I could drive 250 miles and it would still read FULL. Maybe its because of how the arm swings. It gives good resolution at the bottom where you want it.

I'll pull it tomorrow and ohm out the rheostat (sp???) resistor and check the ground.

Thanks again
Tim

 

The sending unit uses resistance to tell how much gas is in the tank based on the position of the float. As all electronics get older the resistance increases which would induce an error in your gauge reading. Ethanol gas has a tendancy to make this happen sooner. I pulled out my sending unit a couple weeks ago and it is very rusty. I would recommend replacing yours along with the pump.

 

There is an issue with ethanol in gas that causes deposits to form on the sender and give erroneous readings. You can try a couple of doses of Chevron Techron Plus additive or the GM juice, p/n 88861011.

 

Hello Cad,
Resistance ... yes. I measured mine E - 10 ohms; F - 110 ohms
After I measured it 10 times, I started wondering why did I take it apart? It wasnt open; it wasnt shorted. It gave a resistance - 10ohms at Empty which is per the spec. If Full is 90 oh,s then it you can drive on full for 100+ miles and the gage keeps reading full until you get down below 90 ohms. The float is connected to a rod which makes spins and there is small spring loaded contact on the end which runs on the coils of the resistor. The point of contact was perfectly clean - heck, it was wiping the coil and the spring was still springey.

Electonics? What electronics are you talking about? There are no electonics in there - just a variable resistance which is sent to the computer. The computer has a table; 10ohms 0-ticks ... 90+ ohms Full.

I cleaned the coil with carb cleaner - put it back together; the reading didnt change. I'll have to keep a wooden dowel in the car to check the level - the next time I fill it up I'm going to check it with the stick and carve a knotch in it with a pen knife. When it gets to 3/4, I'll check it again and put another knotch in it; same for 1/2 and then see whats up at the bottom near 1/4 where I'm getting bad readings. I think I'll start carrying a gas can and one of the old working pumps that I replaced ealier.

Thanks

 

Corvette Recycling---$200 WITHOUT a pump. Add another $80-90 (I think) for a pump. You're still at about $300 with tax, plus shipping. Some of the others are $20-30 more.

"New pump and sending unit---$300.
Peace of mind while cruising--PRICELESS."

 

Running your Vette that low on gas is causing your pump to go out. Get a new pump and keep some gas in it.

 

The gas in the tank cools the pump.