Suburban Fuel Pump

I have a 97 Suburban K1500 and at 40k miles it started having power loss problems and it would not rev over 3 grand. It was towed to the dealer as I purchased the GMPP extended warranty, only to find out my fuel filter was clogged and they charged me $70 to replace it ouch.....

I really do maintain my vehicles but my previous GM; 92 K-Blazer (re-named Tahoe in 93) was a nightmare. I was very anal and changed EVERY fluid and filter every 10k miles except oil that was every 3k with Mobil 1 and everything broke twice. From the radiator, working your way back to the rear wiper motor there were over $21k in warranty repairs up to the end of the 70k mile extended coverage....THANK YOU GMPP. So when I shelled out the $40k for my new Suburban I thought why be so anal if everything breaks anyway. (I do change the oil every 3k with Mobil 1) And I did purchase a 100k mile GMPP with no deductable.

Back to the fuel pump, what I didn't realize is that the clogged filter weakend the fuel pump and my truck was getting harder and harder to start until one day it wouldn't. Now having 49k miles on it, my Burb was towed in again (luckily both times it died in my garage). The fuel pump and strainer were replaced under warr. and I started changing the fuel filter every 30k miles per the book.

This past weekend my fuel pump died again with 108k miles on my truck and with no GMPP warr. I decided to fix it myself where it died, yes....in my garage for the third time (I must live right or something?). Discussing this with my neighbor, who works for an electrical component supplier to GM, he informed me that the electrical connection on the fuel sending unit and wiring is not adequate to supply the fuel pump with the 11 amps it draws. This is like running a toaster off a long extention cord, there is a current drop so everthing gets HOT...VERY HOT! which causes pemature pump failure cause it gets too HOT also. And GM does not want to do a "recall" due to the number vehicles involved but, it does explain why this is a common problem with GM trucks and SUV's. And this problem is amplified in Suburbans because of the long wire run back to the tank.

I pulled the tank this weekend to find some sort of sealant melted on top of the fuel sending unit with bubbles in like it was boiling. Then I pulled the sending unit with the pump attached to find the stainer almost black and rubber insulator melted on to the pump....yeah this thing got real HOT! There is a white plastic baffle in the bottom of the tank and it was melted with an imprint of the strainer in it.

After a new fuel pump, strainer and filter and my Burb is fine again. The heat problem has me concerned so I'll be changing the fuel filter (in frame rail) every other oil change. Some web sites had mentioned fires so anyone who reads this should change their fuel filters if you haven't done so in the last 20k miles. My Burb is often mistaken for a newer one and when I tell people it has 108k miles on it, they can't beleive it and have to check the odometer. What I saw inside my fuel tank makes me nervous and I will probably be looking at the new Volksie Tourag when I replace this truck.

Sorry to be so wordy but I felt this potentialy dangerous situation should be explained in detail!

I have a stalling 93 suburban 1500. I have had it in the shop twice and it started each time when it was towed in. Sat for a day now won't start turns over but won,t start. Diagnostics show fuel filter sensor Code #?. I have full fuel tank and am hesitant to drop tank but I want to get vehicle started and sold before winter sets in.
I was hoping for some direction RE: is it a big deal to get tank off and replace eg pump etc.
Thanks Doug
I had replaced filter 1 yr ago and can smell gas by injectors

First, did you have it towed to a GM dealer or a local shop? The reason being is that you may not have a fuel pump problem, rather some bad sensor or problem further down the fuel chain. Maybe check the fuel pressure and definately replace the fuel filter. I knew for sure my pump was bad because when my tank got down to the red it would howl, and it wouldn't start instanly it would crank for a few seconds which was starting to increase with time.

However, if you do drop the tank; remove negative battery cable first then spray up the clamps for the filler and vent lines and also spray up the strap bolts. Then siphon out ALL the gas you can, you want the tank as empty as possible, it also helps to jack the truck up the same height or more as the floor jack you'll be using to lower the tank (the tank will just clear the hitch sliding on the floor with nothing under it). Then disconnect the fill and vent lines, supprot the tank and begin to loosen the straps, each one a littleat a time. My tank did not lower at all...only the plastic cover came down when the straps were undone. The tank has foam pads on the front and back and they were rusted in to the frame so bad I ended up using a crow bar and sledge hammer to get it loose, the crow bar was wedged between the frame and the tank lip/seem in the back near the hitch reciever. Right then I thought....why the hell am I doing this? Then the fuel lines were rusty and wouldn't come loose either so I had to pull the sending unit with the fuel lines attached. This was accomplished by having one end of the tank about 4" off the ground and the other about 8" so I wouldn't strain the lines. Your'e supossed to remove the lines and electrical connector then lower the tank. Job is starting to become a pain in the as_.

Due to my method of removing the sending unit, a ton of sh_t fell in to the tank so I had to flush it out with water in order to rinse all the rust and junk out. Then using a wet vac to get out the rest of the water and leaving a hair dryer running on high for 6+ hours to make sure ALL the moisture out! (this was done with the tank in my driveway, not near the truck!). Iwas starting to feel like McGiver.

When reassembling, make sure all the pump lines and connections are tight and that the pump is seated well in the bottom mount and make sure the screen filter is on tight and NOT interfering with fuel gauge float. I sprayed some silicone on the o-ring to make sure it sealed and make sure the locking ring tabs are bent enough to hold the sending unit in tight enough (I didn't and had to pull the tank back out from under the truck to tap them down a little and then it sealed properly). Also, if you're not going to flush the tank, make sure you stuff rags or paper towel in the fill and vent line hoses to keep out any dirt!

This was not a very pleasant job but I saved myself a couple hundred bucks (two and a half tanks of gas!!!). And depending on the shop, either the costs of new lines and a sending unit or a half assed job with rust in the tank and spliced lines. Oh well it's over :grinno:

I will agree with changing the Fuel Filter regularly. I read recently once your vehicle is 5 years old you should replace it every year due to the rust buildup in the tank. Sooner if you use Ethanol. I just recently replaced mine on my sub I bought 10 Months ago. It is like a new truck. I must have gotten 20 or 30 hp back. I am finally noticing the affects of the K&N filter I put in.