1999 Suburban Won't Start, Makes Weird Noise

Lanse

Well-known Member
Hey, guys!

So, to make a long story short, I've purchased a 1999
government owned K2500 Suburban to turn into... A project... :p

When I went and bought it, it fired up like a new one (after
changing out the starter) and all was well...

I brought it to my shop, and let it sit for roughly a week (maybe a
little less), and then went out last night and tried to start it.

The truck would crank and crank but wouldnt take, didnt even
sound close to actually starting. Its been through like 3 fuel
pumps (previous owner got so tired of changing them he cut an
access door in the floorboard haha) so thats what I'm leaning
towards. The fuse looks fine...

Heres the thing tho, when you stop trying to start it, the whole
truck lurches to the side with a "phoomp" sound, three or four
times. Ive never encountered anything like that...

Truck has the 5.7 treefiddy in it...

Any advice? Thanks in advance guys... :/
 
Just going on a limb here but have you checked the timing? Gov issued low miles but HIGH idle time might have stretched the timing chain or cam sensor bad ? I don't know if it's a coil pack or dist ignition but sounds like a timing issue to me.
 
I had a similar issue with a Russian built truck once . The fuel pumps were burning out and it would only start after cranking for ages . This burnt out the starter as well so, it is sounding a lot like your issue . The fault was a small backflow valve , this was supposed to stop fuel draining back into the tank after the engine was shut off , it failed and the fuel lines were empty every time you wanted to start it . The long cranking time primed the lines and allowed it to start , sometimes . I fixed it by piffing the stock valve and replacing it with a fuel shut off valve from a LPG fuel system . These can be wired to shut when powered off and so maintain the prime of the fuel line . Worth a try , I think I paid all of $15 Aus . for it . As far as the weird groans go I would consult a Catholic priest :)
 
Lanse try running a ground to the fuel pump first see if that helps. Second run a positive wire to the pump bypassing all other power see if the pumps works ie fuel comes out at engine. I have known if it has run out of gas it will burn out the pump. Third if the fuel is old will not fire up well (new gas has a short life 3 months or their about) Forth check the timing can have stretched.
Ypop
 
If it's already gone through three pumps... chances are good this one is shot too. That's what it sounds like to me. I've had that happen. Turned out there was sand/dirt in the tank. That eats pumps up QUICKLY. Thouroghly clean the tank, install a new pump and it was fine. On yours the first thing I'd do is find out if the pump is even running. If you cycle the key on and listen near the tank you should be able to hear it. If not, get the tester out and see if it's getting power. If it is... see about testing the fuel pressure. If it's not running... find the vehicle inertia switch and reset that. If it still doesn't work, see if it has power at the inertia switch. If not... trace back to the pump relay wherever that's located... probably under the hood in one of the electrical boxes. Take that for what it's worth... I'm not a chevy guy...

Rod
 

YOU NEED A FUEL PRESSURE GAUGE... :twisted: A HEI spark tester would also narrow it down... Its up in the air till you confirm sum'n.........Someones gonna come along and say I had a Ford pinto that did the same thang :x Its a cheeby a different animal... With out fuel pressure readings and confirm know good spark we are all in the same place you are LOST....

Do you by chance can get hold of a AC R12 pressure gauge set :?:
The fittings are the same as yer fuel test port :idea: ... A Hei spark checker is cheap invest in one....

If it eating pumps it could be a bad tank but that useless info post your test readings first...
 
Mine had a bad relay under the hood for the fuel pump. sometimes wouldn't start and sometimes would quit running . I changed the relay and never changed the pump it was cured.
 
My '89 1500 had running issues once and when I took it in to my son and his buds, one of them crawled under it and slapped the bottom of tank rather briskly and it started. They all chimed fuel pump! Fyi, as for strange noise, how do the motor mounts look? x2 fyi.
 
Don't ask us, ask the truck!

:)

Even if you think you know what's wrong, check the codes before doing anything.
 
Already good replies here. I actually own a 99 suburban and had something similar happen. Turned out to be a bad connection where the harness plugs into the pump (on top of the tank).

As mentioned, you should be able to hear the pump run for a few seconds when you first turn the key on. Check for this first.

If the pump runs next check the fuel filter. Modern fuel filters catch a lot finer crud than the old inline filters we used for carbs. The fuel filter is inside the frame almost directly under the driver's seat. Very easy to remove. Take it loose and hold your fingers over the ends so as to trap some fuel. Bang it lightly on something solid and then pour the contents into a cup or something and see if there's a lot of trash in the fuel. If there's more than a tiny amount, stop there and put a new fuel filter on.

If the pump ran and the fuel filter is ok then check for spark. Just unplug one wire, attach a plug (an extra or pull one from the motor) and let it sit where it's grounded but you can still see the end. Have someone crank it over and see if you have good fire.

If the fuel pump does not run when you turn the key on, then it is either: Dead, or harness connection bad or fuel pump relay. The fuel pump relay is located in the engine compartment on top of the fender in front of the driver. It is possible to pop the cover off the relay and troubleshoot it with a multimeter.

If you end up getting into the fuel tank, shine a bright light in there and see if there's trash in the tank. As mentioned, that will eat on the fuel pump.

Let us know what you find!
 
try starting it with a small shot of ether. If it fires, and then behaves for the rest of the day, that could be a bad fuel pump or fuel pressure regulator.
 
I feel compelled to reply because of all the grief that Chevy fuel pumps have caused me. #1. Buy only a Delphi or AC Delco fuel pump module. #2 Never let the fuel level get below 1/4 tank. #3 IMHO, bigger wires should be run to the pump. Take some time and run #12 wire for power and ground. #4 Replace the Metri-pak connector if there is an updated connector available. #5 Clean the tank. #6 Should you have your fuel pumps continue to live short lives, put an Airtex E8248 inline between the fuel pump and engine. Wire it to a relay, power it from the accessory stud in the fuse block, and wire it to turn on and off with the in-tank fuel pump. ALWAYS REPLACE THE FUEL FILTER WHEN YOU REPLACE THE FUEL PUMP. NO EXCEPTIONS, DOES NOT MATTER IF THE PUMP WAS REPLACED 2 WEEKS AGO.
 
Lanse, It could be a distributor cap/rotor problem (COMMON).

(They carbon-track or fail internally.)

The coil wires have been known to "open", as well.

If the ignition module shorts/fails, it will give one spark, when the ignition switch is turned off, to what ever cylinder the rotor s pointing at, and can give some weird pops/snorts/noises/backfires, as well.

A failed cam sensor (in the distributor), or failed crank sensor can cause some goofy no-start or back-fire problems, as well.





NO need to guess about the fuel pump/fuel pressure, as the Vortecs have a test port on top of the engine.

You need 50 PSI or more or it"s a no-go. The original Vortec injector "pod" feeds individual little plastic "injectors" in each intake port that have a spring-loaded check valve. They work much like a diesel injector, only at MUCH lower PSI and won"t pop/open unless the minimum fuel pressure of 50 is there.

Please keep us informed as to what you find!
 
"Buy only a Delphi or AC Delco fuel pump module."

I thought that was a plan, as well, 'til we did just that on my son's '98 Tahoe a few years back. The Delphi made it less than 2 years/14,000 or so miles!
 
Sorry to add another variable but check the ignition switch. My 97 acted just like that and it was that switch. It made unrealiable contact and would not power the fuel pump one time and the next time not power the ignition, but still crank it. New switch no more issues.
 
Yep,

Open circuit right where she goes in to the top of the tank. Many, many fuel pumps before finding this fault.

Allan
 
What's funny is that I did that little troubleshooting job in a parking lot 30 miles from home with a free multi-meter form harbor freight that I happened to have stuck in the console one time.
 

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