PsychoDodo

Sorry for wall of text incomming.

2001 silverado, 4x4, 4.8L. Reg cab shortbox. Low km on the engine.. appx 155,000km on the odometer.

(Not sure on proper terminology) Drove her off the lot back in 01. (Work trucks for work, my baby for me)

Had her recently sputter and die at an intersection. Attempting to restart would give the chu chu chu vroom sputter cough die.

Got it towed home, my first thought was fuel pump.

Decided to start with the fuel filter, that hadn't been changed in forever (10ish years) couple millwright friends suggested to turn the ignition to re-start (as if engaging the glow plugs on a diesel) to engage the fuel pump after I broke the lines to make sure the fuel pump was working.

They also agreed that the fuel pump either works or doesnt, it doesnt really do a halfway work sometimes others not work.

So, got the fuel filter out, did that and sure enough fuel came firing out for about 10 secs or so then stopped, I'm guessing that's normal, Google's failing.

Put the new filter in (yes it's not in backwards), cycled the re-start a few times to push the air out.

Started up fine, for about 30 seconds then died. Okay, figured more air in the line. Ended up killing the battery and using a booster jump kit to try make sure its purged out.

It's gone through easily 2 dozen attempts to start with the odd brief "cough " as if it's trying to start. So I'm kind of ruling out air in the line.

Googling says filter pump maf and a couple other things. I havent tried unplugging the maf since before I did the filter and that's one of my next things to try but I dont think it's that.

Before I changed the filter and broke the line it would somehow let enough fuel seep into the engine that it would fire up for 5 to 10 secs. After sitting for 10 mins or so, no dice after changing the fuel filter. (Gonna try it next for the hell of it)

But I'm kinda at a loss, it's got to either be the fuse or the pump at this point right?

I can replace both if needed but I dont want to just dartboard this. I dont have a diagnostic tool and want to try do as much as I can before I have it towed over to a mech shop.

Any help would be appreciated.

Irish_alley

a fuel pump can be weak, need to put a fuel pressure tester on it. my 02 was "running" with only 22 psi. should be 52-60.

chem_man

While you are testing the fuel pump using the fuel pump pressure tester, check the operation of your fuel pressure regulator to make sure it is operating properly and does not have a defective diaphragm.

therewolf

hey, PsychoDodo, and chem_man, Welcome to the Chevy Forums.

There's a few things to consider:
1.There's a fuel screen ( or "sock") in the fuel tank, at the base of the tank, just past your fuel line inlet, which may be clogging, and causing issues.
2. Shout out, to all, the standard warning- DON'T let your tank run low, and run on 1/4 tank or less, on a regular basis, this creates
unacceptable amounts of condensation and crud in the bottom of the tank, which in turn, waters down your gas, clogs your filters,
causes premature pump failure, etc.
3. While checking the tank screen, you'll probably find your fuel pump is located nearby, at your vehicle's mileage and age, most the meat is off the bone,
on your fuel pump, if it hasn't failed already, while the tank's down, just replace it.
4. OBD scan tools have gotten cheaper and easier to use, It sounds like you do a fair amount of your own maintenance, It would be well worth your while,
(and money) to pick one up, considering the hourly mechanic rate, (85$/hour+) these days.

chem_man

therewolf, thanks! Just as an FYI, yes, I've been do the overwhelming majority of the maintenance and repairs on GM vehicles for way longer than I care to admit (my wife says she married me because I am handy and more affordable than a mechanic!). Also, I read more than post, and I have a several OBDII diagnostic tools including a GM Tech II clone that I am learning how to use.

I'll second your reminder to not letting one's gas tank get down to darn near empty before refilling the tank for a variety of reasons.

By the way, you have got a great forum here!

PsychoDodo

Thanks for the welcomes.

Fuel tank is over 3/4 full and I cant get the engine running, nor do I have a tester atm to use. I do have a pump on order coming in tho in a week or so and the fuel was coming out visually decent and clear when I had the filter lines disconnected.

I did after using the jumper pack manage to finally get the truck running briefly (about 30 seconds) however any attempt to give it gas or letting it idle beyond about 10 seconds caused it to immediately stall.

I'm going to agree with the above statements and guess the pumps barely working or perhaps the actual lines on the pump could be cracked so it's just puking fuel back into the tank.

Even though its low mileage the thing is coming up on 19 years old so it's probably given up the ghost. It's the stock OEM one.

Once the pumps replaced if she still doesnt go I'll pick up a tester and see.

I'll let you all know how it goes once I have the new one installed whether that solves it or not.

Thanks.

Edit: how would I check this screen/sock while I'm doing this? (I'm not going to be dropping the tank to change the pump).

chem_man

PsycoDodo - Autozone, Advance Auto Parts, and O'Reilly Auto Parts all have loaner tools, including a fuel injection system pressure tester that you can use for free (leave a deposit - get deposit back when you return the tool). You might want to test the pressure before you drop the pump.

When you take the pump out of the tank, it will be an assembly. The screen/sock will be inside of the cylinder that houses the pump.

Good luck!

PsychoDodo

Sorry for long delay, figured I'd give an update however.

It did turn out to be the fuel pump. i didnt realize until I looked at a few videos even more possibilities that it could be. (The fuel gauge on the dash would spike all over the place when the truck wasnt in motion) so that tells me the contacts in the pump are kinda screwy with regards to the float. (You could shift yourself side to side to rock the truck and it would sorta go back to reading normal rather than dead empty on the tank).

I would also get the occasional check engine light after refueling which at first made me think the gas cap seal was fubard but it's just the pump sending wrong signals to the computer.

I was not (based on even the faulty reading) going to drop the tank. I dont have a lift or even ramps and it was reading 3/4 full, that's a lotta weight to try solo bench up, hold in place and remount. Not worth the headache.

I then explored the tilt the bed method, it would have been realistic except I didnt have heavy air/power tools to undo (let alone de-torque? That a word?) The bed bolts.

In the end, I got a zip disc, took my tape measure and simply cut about a 1ft x 1ft hole in the box of the truck over top of the tank. This gave me easy access to the tank and I have a canopy topper on the truck so I'm not too worried about the elements hitting the now cut steel.

Lost some hair because its canopied fro sparks hitting ny scalpe, lost some skin cuz damn sharp edges and a few choice words later got the pump out.

Replacement went smooth except on reconnection, yay chinese engineering, reconnecting the quick connect with the wiring it was all out of alignment and bent out of shape so some careful prying got the contacts set right.

Boost from a buddy after priming it all (cycle key to start as if starting a diesel till the whirr stops and redo a half dozen times or so) and vroom off she went.

It's a cheap pump off Amazon for like $120 so I'm not expecting more than a few years out of it but now the box hole is cut (which I'm making a very nice cover for) itll be a breeze when she craps out. (Or maybe I'll get lucky and get another 19 years outta it hah)

Other repairs have since ensued since this was first posted and I did the change over because you know how it is, you find one thing you find a bunch of others you forgot about and they all demand attention.

Thankfully the others went mostly easily.

Thanks to the community for the help and suggestions.

-Psychododo

Sock was black but not overly plugged, I think she simply failed due to age.

chem_man

Thanks for the update!