what brand is best? and is it wise to change the entire sending unit too? or just the pump itself?

thanks

 

Delphi or ac delco only!!!!!!!!! Search the forums. and i learned personally these trucks ONLY like these 2 brands....airtex's,carters etc are a no no in these vehicles.

Replace the whole unit as you only want to drop the tank once. might as well do it while its down.

 

I was looking too, glad I saw this. Only got a bad sending unit and 78K miles, gonna replace the whole thing.

NO use taking a good pump out and replacing it with a problem.

 

I dont know why aftermarkets are so bad in gm's. we put a airtex in my friends ford escort,and one in a ford thunderbird and they have worked fine for over a year. Every one ive ever put in a gm they last from a week,to maybe 6 months. I personally went through 4 pumps in 2 months time in my blazer until i said screw the warranty and paid 100 for my ac delco. no issue since.


send me a pm with your year etc. I found a few delphis etc on amazon etc much cheaper then on auto sites.

 

My sending unit problem ended up being wiring that goes over the transfer case driveshaft near the fuel filter. I posted a picture. Also if your gonna drop that tank dont forget to disconnect the vent valve or youll be bummin. Lots of people break that vent valve and plastic tanks 99 and up have vent valves that are glued into the tank and cannot be replaced.

DELPHI on Amazon. Make sure you have the tools for the fuel lines. I ended up disconnecting them from the fuel line first then from the pump when the tank was out. I havent seen a tool that can fit those lines at the pump. Ended up cutting one up to make it work. The one at the fuel filter cant be removed either. They suck.

 

BigD.. The GM OEM suppliers were in on the design of this weird FI system. They KNOW how it affects the lifetime of the pump.
Aftermarketers figure if a pump works a while, that's good enough. They dont care about warranty either... who's gonna drop their tank every year or so to change a free pump.

Damn, Chris!!!!!

I've bloviated on WHY about 6 times since I've been on here. Check the Fuel Pressure on those Fords and think about FP on Vortec's. Now recall a few things you learned in high school physics!

I might come across as a 'know it all' but sometimes I'm right.

And BTW... Airtex suck on Tbird's too. Ask your buddy with the Bird how he likes his fuel gauge readings now.

 

ok so i will search for the cheapest Delphi or AC Delco pump, but should i change the pump only or the complete sending unit with the pump as an assembly?
thanks

 

You have the option of just replacing the pump. The newer trucks don't have that option. I would take a close look at the 'fingers' on the fuel level sending unit before you put everything back together though. It would suck to replace the pump, then have the sending unit go out.

 

hey thanks. when you say fingers, what exactly are you reffering to? also the metal lines right on top of the sending unit are really rusty looking, but not leaking yet if that matters.

 

If the lines are rusty, you have to determine how bad the corrosion has diminished the wall thickness on the tubes. If they are significantly impacted, they you will want to replace the sending unit.

The 'fingers' I am talking about are attached to the arm of the fuel level sending unit and are what run across the resistance grid to complete the circuit. They should have a rounded tip to them and should be about 2-3 times longer than they are wide.

In the attached picture, the float arm attaches to the white plastic piece in the front of the picture. The resistor grid is behind the arm and the fingers are between the two attached to the white plastic piece.

The picture is from a Corvette fuel pump assembly which is very similar to what is used in the newer s-series trucks. The older ones are a bit different, but the same in terms of principles of operation.