2001 Tahoe, need fuel system schematic

stomachmonkey · 06-02-2010, 07:39 PM

Yes I will be googling and looking for it but figure I'd ask for some help.

History.

Wifes 01 5.3 L Tahoe, 92k on the clock developed a sticky fuel gauge float a while back. Did not feel like dropping the tank so told her to top it off and use the trip meter to guesstimate when she hits a half tank then top off again.

Been working just fine.

Today she calls, picking kids up from school. Truck won't run. Starts but runs rough and dies. Assume she is out of gas but she insists no. Neighbor runs up with a gas can and dumps in a couple of gallons but still no go.

Tell her to leave it and I'm on the way home.

Go to truck, starts but runs rough, peddle it and can get it to idle better but it's definitely starving.

Open airbox to check filter, it's clean so leave airbox open. Try to start again but now won't even run rough. (Just hit me, too lean due to open airbox)

Check fuse box, injector fuses all ok, swap fuel filter, ignition etc... relays with same relays from known working non essential components like A/C and horn. No start.

Assume at this point fuel pump is shot. Close everything up, come home and call roadside to pick the thing up. Look for deal on fuel pump assembly, damn these things are expensive. $250.

Roadside shows up, go to meet them and the thing starts, runs rough, need to peddle it to keep it running. Put on flatbed and they bring it home for me.

Last load of gas was last week, wife says it was running funny last week but I drove it this weekend and noticed nothing. Possible bad load of gas but doubt it.

Pretty sure it's a blockage somewhere so looking to check the obvious accesible points of failure before dropping the tank which is about half full.

Thoughts?

Dantilla · 06-02-2010, 08:16 PM

I have a 2001 Chevy pick-up.

My gas guage has been whacked out for quite a while, so I just fill up by the trip odo.

At about 160,000 miles, my fuel pump recently died on the freeway. I was just a few miles away from a Chevy dealer, so I had it towed there. At the roadside, I checked the little schrader valve on the fuel rail, and gas spurted out, so I was pretty sure the pump was fine. The pump was producing some volume, but was not building sufficient pressure. I had just filled the tank about 20 miles earlier,so it was actually easier to loosen the box of the pick-up to access the top of the tank. Guess that won't work with a Tahoe.

I do have the factory shop manuals (5 volumes) that cover all the Chevy and GMC trucks, Suburbans, Tahoes, Escalades, yada yada. They are stored in a hangar over at the local airport. Next time there, I can dig them out and see if I have what you need.

Racerbvd · Racerbvd's Garage

Hate to tell you this, but you will have to drop the tank, fuel pump is bad. It is a common problem, I have replaced 3 in my Suburban

Did the same thing as your wife's....

jpk · 06-03-2010, 06:23 AM

There's a fuel pressure regulator on the driver's side fuel rail that can cause idle issues; it's relatively cheap ($30) and very easy to replace. It's a little metal can about the size of a walnut with a vacume line attached. De-pressurize the fuel rail (using the schrader valve on the passenger side rail) before you remove it.

I just swapped the pump in my '99 silverado as a preventative measure. It was a royal PITA.
Spend a couple of bucks and get the Delphi pump; it'll last you another 9 or 10 years. I've heard some of the cheaper aftermarket pumps failing after less than a year.

stomachmonkey · 06-03-2010, 06:37 AM

Quote:

Originally Posted by jpk

There's a fuel pressure regulator on the driver's side fuel rail that can cause idle issues; it's relatively cheap ($30) and very easy to replace. It's a little metal can about the size of a walnut with a vacume line attached. De-pressurize the fuel rail (using the schrader valve on the passenger side rail) before you remove it.

I just swapped the pump in my '99 silverado as a preventative measure. It was a royal PITA.
Spend a couple of bucks and get the Delphi pump; it'll last you another 9 or 10 years. I've heard some of the cheaper aftermarket pumps failing after less than a year.

Thanks for the tip.

I've resigned myself to dropping the tank, that way I won't be so pissed if it comes to it.

But am looking to check the system from one end to the other before committing to it.

Nothing worse than doing the big job expensive only to find it was something relatively minor and cheap like a bad regulator.

fastfredracing · 06-03-2010, 07:59 AM

Best way to check and verify for sure that it is indeed the fuel pump would be to borrow/buy a fuel pressure tester. I think ( from memory) that you should have something like 65 psi.
Nice thing is, you should have a functional gas guage after the fuel module replacement.
I would change the fuel filter at the same time as the pump as well.
Dropping the tank is not that bad, but it will be a little cumbersome if you are doing this job on the ground ( jack stands). If you can, empty the gas tank into 5 gallon fuel cans, or buckets, so that you dont have to fight all of the weight of the fuel as you are installing the tank again.

911boost · 911boost's Garage

My 2001 Tahoe with the 5.3L did this as well once, it ended up being bad gas. Mine would run though, and cause the CEL to come on.

I agree that it sounds like the pump.

lm6y · 06-03-2010, 05:50 PM

I've changed three of these. All three passed the tests in the shop manuals, but still ran rough, or not at all. Changed the pumps, and fixed them all. Save the time, and the headache, put a pump in it.

Brian 162 · 06-03-2010, 05:51 PM

Sounds like the fuel pump. My old Tahoe (97) fuel pump died after I put gas in it prior to letting the tank get close to empty.I was told not to let the tank get below 1/4, because the fuel cools the fuel pump.
Get the factory pump. It's worth the extra coin.
A co-worker had 2 fuel pumps installed on his Silverado pick up until he got the factory pump.

stomachmonkey · 06-03-2010, 06:24 PM

Well it looks like I'll be dropping the tank.

Picked up a fuel pressure gauge at Autozone, gotta love their free tool loaner program, and a fresh filter.

Swapped out the filter first.

The crap that came out of the old one was pretty bad, gas was almost grey, lots of stuff in suspension. Blowing thru old filter and had a fair amount of resistance compared to new.

New filter in, started right up, ran nice and strong, reved really nice. Ran it a 2-3 minutes, reved it hard and it started to starve and die.

Heres the contents of filter and the line before it.

What I thought at first was a lot of silt is water with a silt layer between it and the gas.

So looks like a load of bad gas, lot of water and dirt. This is the kind of stuff that happens when the stations tanks are really low.

So looks like I'll be dropping the tank to clean it so will replace the pump "as long as I'm in there".

ODDJOB UNO · ODDJOB UNO's Garage

hey you have another option..............

take the body off the frame and you wont have to drop the fuel tank.

yeah i have a 99 gmc k-1500.....................truck. taking the bed off is another way of doing them.

doing it on the ground sucks royal donkey weenies.

get it on a lift after draining gas out(otherwise its damn heavy)

the cause of this is running them low on fuel. hit a 1/8 tank and fill it up. they are cooled by the fuel. no fuel, gets hot, no worky.

ask me how i know 218K original miles . never wrecked. just had to rebuild tranny cuz dum azz kid thought he was ricky racer with tranny.

its a freeking truck. motor dies $2400 bucks for crate engine.

divorce forces sale deal $10k with 91K on it. ive run the piss out of it. k&n filter and magnaflow exhaust and new cats. other than that stock w/bfg's all terrains.

great truck as always with some quirks...............like the fuel pump.