drewkeen

This happened to me today. I noticed I didnt hear the fuel pump and more so I added a gallon or two and that fixed it. I then filled it up and it only took another 8-9 gallons. There is most likely an issue with my jet/siphon pump from my reading on here. I am still a bit confused though.

My car is a 2002 model, is there a write up on how to clean this? I also though that if there was an issue the fuel gauge would drop to empty to warn you, mine didn't.

What is the best and/or easiest way to remedy this issue?

LoneStarFRC

Based on your symptoms, etc, I would go ahead and replace the right fuel pump/sender unit. AC Delco (MU1218), Bosch (67466), Carter (P74894M), all offer it new, pick one. Just shop around first as prices vary widely.

HTH

andrec10

Got nothing to lose by trying Techron.

65GGvert

Techron won't fix running out of gas with 8 gal still in the tank. Techron fixes gauge issues.

Mickeyrx70

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Listen to LoneStarFRC -- he knows what he's talking about.

dba4life

Believe I have the same issue, any idea on the labor costs?

drewkeen

Do I need to drop the tank to replace it? Is there a write up anywhere or at least a way to drain some of the gas out before I try to support 40+lbs of fuel as well as the tank?

Any suggestions on where the best deal is for the unit or places/brands to avoid so Im not doing this again in another year?

john8642

Does anyone know exactly when the change was made or how to tell which system a 2003Z would have?

LoneStarFRC

No need to drop the tank on your year model. There are a couple ways to get remaining fuel out, but trying to use your left-tank electric pump probably won't be of much help if it's unable to transfer fuel from the right tank in the first place. Since there are only two hose fittings (and one electrical connector for the sending unit inside) on the right tank, you could quickly release one of the two (no tool needed) and have a section of clear vinyl fuel hose (5/16" IIRC) at the ready to equally quickly push on to the nipple, then let it drain into a (preferably clean) container. You can use regular black fuel hose of course, I just prefer the clear stuff. One fitting/hose is a supply (from the left tank) and the other is a return (back to the left tank). Depending on the fuel level inside, if you get little or no flow, connect your hose to the other one. Even when the flow stops, you will have some small amount of residual fuel remaining, probably on the order of less than half a gallon, so have a pan or wide mouth catch-can ready for when you unbolt the six flange retaining bolts. Once you get that far, the worst is over. If you want, you can try driving the car some to lower the fuel level first, but don't get too carried away and run out of gas again unless you have a small gas can with you.

Be SURE to follow the correct procedure for tightening the flange bolts on the new unit and DO NOT over-tighten. The new unit may require some snaking and twisting to get it in, so take your time and don't force anything. Some kits may come with special "breakaway" bolts, so you won't need a torque wrench, as the heads are designed to snap off when proper torque is reached. If not, use a torque wrench set for INCH-POUNDS. This info is in the instruction sheet. I would also recommend reaching inside the tank with some clean rags/toweling first, and give the bottom area a good wipe before installing the new unit in case there's any debris. The hole is about 4" - 5" so you can easily look inside to inspect as well as reach in. You want it as spotlessly clean as possible naturally.

I would feel perfectly safe in using any one of the brand names I posted. They are all good quality, but just shop around for the best prices. Amazon, Rock Auto, Jeg's, Summit, Pace Perfomance, etc, maybe even Scoggin-Dickey. I would think Amazon will likely have the best price or maybe even Ebay. The current GM part number is: 89047748 if you **gulp** decide to buy from a GM dealer.

The key is: shop around. I'm guessing AC Delco will be the best price.

john8642

Thanks for the reply.

mike_engr

I also ran out of fuel about 2 weeks ago (2001 Vert, 36k miles, owned 3 months).

The last gage reading I remember was about 1/3, and I never got any DIC reminders to refuel before it suddenly sputtered to a stop. Checked everything: Fuses, relay, squirted the rails, etc, etc,, never really heard the fuel pump either, but I also didn't smell fuel at the tailpipe after cranking it for awhile so I knew it was a fuel delivery problem.

I think mine was a gage problem (not a transfer problem) because of the amount of fuel it eventually took to fill it up.

But if I were you I would try TECHTRON and really good premium gas fill-ups a few times - - Just run it to half-tank and refill. Maybe carry a Jug and run the car below half full as you gain confidence. That's what I'm doing and so far so good.

You got nothing to lose. It's a lot cheaper than throwing parts at it. You can even find some DIY's on blowing out those gas lines too.

Maybe you'll get lucky and enough of the treatment will get over to the 2nd tank to free-up your plugged Jet/Siphon system....

Like I said, you got nothing to lose. I'm about to go on another TECHTRON shopping trip myself!

65GGvert

I don't think you're understanding that it RUNS OUT OF GAS at 1/2. It's not that the gauge isn't working, he has 8 gallons of gas left in the tank and the gauge reads 1/2. The gas isn't transferring from one tank to the other, techron cleans the contacts for the sending unit to the gauge. That would help if he actually had zero gas and the gauge read 1/2, but he has a half tank left, just like the gauge says.

mike_engr

I think I'm understanding well enough. But I think you're not reading well what I wrote.... I wrote about his plugged jet siphon (transfer) problem and blowing out the lines.... how much clearer do I need to be?

Are you asserting that gas treatments and blowing out the lines will NEVER EVER fix a clogged or restricted .050" siphon orifice without replacing parts? I don't think anyone can claim that.

all I said was its worth a try.... geeze

robert miller

What is your fuel pump pressure in the car. If your pump drops pressure below 45 to 50 psi. the pump will not transfer gas from the drivers side to the pass side tank. Which will let the car read the 1/2 tank but also run out of gas.

You have a pump in the drivers side tank that pump gas over into the pass/side that keeps both tank level at all times. But if the fuel pressures drop below above psi this will not happen. Robert

robert miller

OK you know more than me on you write up for sure. But I do know in a 2004 if your fuel pressure drops or is set below like 45 or 50 psi. It will not transfer fuel to the pass/side tank. This I do know for sure. Robert

3boystoys

I've seen (with my own gauge on it) a Fuel Injected car idle with 8psi, put it in gear and it dies.

dadaroo

I don't want to get into details, BUT, if you want to FIX your problem
you need to listen to:

LoneStarFRC
65GGvert
and-
8VETTE7


These are great tech guys. Just say'n. Mr. Sam

PS: Techron is a great product but it is intended for level sensors that are fouled or to prevent fouling.

LoneStarFRC

Thanks for the kind words Sam. Considering the huge amount of your own personal time you have devoted to helping others here on the board, I consider that a compliment.

robert miller

Very nice write up on this problem.

LoneStarFRC

Thanks RM. Unfortunately for me, it was a bad experience several years ago with this very issue, that caused me to have to learn so much about the C5 fuel system. You know what they say about experience - especially the bad ones - sometimes being a harsh but effective teacher.