Koda

So I went to run the Tahoe I bough 6 months ago, hadn't run it in a couple months. Good battery, crank, crank, crank, dickall.

Security lights tests, but goes out, so I do not believe it's the 98 era GM passlock. Poured some gas in the throttle body, but I had no starting fluid, and it wouldn't catch even once (it might have caught for one hit, but no more.)

Garage was about 45 degrees inside. High mileage truck I got a deal on, wanted a second car and one that had 4x4, hadn't run it since I've been renovating my house and living elsewhere.

Fortunately, there's a Schrader valve for a fuel pressure gauge, and I will, once I recharge the battery, go look for spark. Unless something made a nest in the air cleaner, which I neglected to pop open cause I'm forgetful; I'm thinking my fuel pump or regulator went **** up.

Anyone know these era GM blocks and know their troubles?

oldstata

96-99 intakes leaks coolant
Fuel pump sending unit grounds break from the inside
Ignition harness burn up
Trans
Other than this I think they are great trucks I've Owed mine for 16 years currently has 210k bought it 3 years old

tru-blue 442

95-03 you have to change fuel filters on a regular basis or the pumps go out without warning. Check with the silveradosierra.com forum. You may be able to do a search
and come up with the problem. I have a 99 w/350 vortech and 200K, great truck.
At 85K I had to replace the intake gasket as well.

Koda

Thanks for advice. I've done nothing to it since owning it, so it will need lots of little things, like that fuel filter. Engine is filthy, too. But, as long as I don't have to get it running the next day to go to work, working on them is fun.

Koda

Hrrm, this is odd, but I'm not complaining. I haul my charger down there from grandma's, hook it up, plug it in, get 0 amps. I can hear the diodes humming and I just used the thing. Checked the connections, still got 0, so I think I shorted the battery or some stuff last time, even though the hood light is on nice and strong.

Figured I'd at least try it before troubleshooting, and the thing fired instantaneously. I think I have a coolant leak, it must've seeped under pressure because it dribbled as I backed out. Went on a ten mile drive, checked everything out, brought it in garage, shut it down, then restarted to make sure it would, ran more, and shut down.

Lots of questions still on this car; I'm not going to let it sit for multiple months though.

oldstata

Coolant most likely the intake gasket can be the radiator as the tanks are plastic and crack

steverw

The transmission in my 03 GMC Denali is beginning to slip some, it seems between 2-3 shift. I was quoted $2000 to 2300. for a rebuild just today. Other wise the truck has been great. The only thing i have replaced is an alternator, waterpump, and brakes. It has 187,000 miles. Im worried the fuel pump will go soon.

don71

Friend of mine recently described same problems. 104,000 miles.

Ignition coil detected as bad, and it was good for a month. No start again, the usual tune up was done, wires,plugs, cap and rotor were replaced and it was good for a another month. Then same problem, wouldn't start.

Shop diagnosed some kind of switch in the column. Replaced and problem occured again about another month later, no start.

Finally fuel pump discovered not to be working properly. Six months now, and it seems good.

How's that for throwing parts at it.

Koda

I will probably throw some parts at it.

oldolds88

temp sending unit on my 97 would keep it from starting

Railguy

I had a ground wire problem battery was good just wouldn't turn the engine over .
How are your head lights?
Railguy

Koda

They are strong. It would crank fine, but the one episode of trouble it would not start, or even catch. It MAY have fired one cylinder, once.

OldOlds, I think this thing has questionable electronics galore. I wonder if it's under the GM key switch recall?

Koda

Lol. It is not. Haha.

bluecab

I've had my '96 Suburban since new, now has 240k on it and the motor had never been open.

When it was a year old it lost reverse gear and was fixed under warranty.
I had to replace a fuel pump about 15 years ago, and the distributor needed replaced as it was cracked and letting in water when it rained.

Thats it though, burns no oil, always change it at 5000mi with mobil 1.

It has hauled everything imagineable, cars, granite, building supplies.

I will get another when the time comes.

Koda

Update: Went to run it tonight (it gets run every couple weeks), no start.

Went over to my driver and grabbed the can of ether I had bought for the occasion. It responded to small blast of ether by hitting on a few cylinders. Bigger blast of ether started it up.

Ran it for five min, shut it down. Started up fine. Moved it outside, ran it for a few min, shut it down.

Moved other can in garage, started oil change, did some other stuff, got back in this one, started and died. Nothing on second crank. Shot of ether got it going.

Went for a drive, ran an errand, some 15 miles. Ran fine. Shut it down at destination. Started then died on first attempt to start. Started and stayed running as I socked the gas once hard on the second crank.

Drove home fine. Put it outside. Did what I needed to do for a few hours in the garage, moved daily driver out, went to start this one and booted the gas right when it caught so it stayed running.

Analysis seems to be a fuel delivery problem. Going to go after fuel filter first, but it seems like what a weak fuel pump would do, run fine, just not start well.

Railguy

Check if your accelerater pump is working if it is it's something else. Easy on the starting fluid that very bad for the rings.
Railguy

jcdynamic88

accelerator pump?? with any fuel injected diagnosis fuel pressure and injector signal along with spark should be checked before throwing parts at it. i had a gmc truck come to me that would only start with a shot of ether but then run all day,turn it off and no restart.the ignition module was bad and not giving an injector signal while cranking.does this have a distributor?

bluecab

Check to see if there is an accumulator in the system that is supposed to hold fuel pressure.
Mine always starts great from cold, but sometimes takes a few cranks when warm and I remember on other cars this was a sign of a failing accumulator or pump.

oldstata

Could be a weak pump, but I would think that your loosing pressure and not a weak pump.this set up has one injector and a spider line to each cylinder, I would say either the regulator is bad in that set up or the injector is leaking I have seen both.

I think your on the right track change fuel filter and go from their

lemoldsnut

Do the easy part first. Change the fuel filter. They clog with only a tablespoon of water. They will also cause a shifting issue with a trans. This is because you don't realize you are using more throttle pedal to get more fuel past a clogged filter so the throttle position sensor tells the system you are accelerating at a higher rate so stay in gear longer.

The fuel regulator can be an issue as well as the control module. But a fuel filter is just routine anyway and cheap so change it first. Then I recommend the fuel pressure tests.

Koda

Great advice from all. Will do and report back.

Also ran the 72 Chevy last night, which of course started fine. /roll

Railguy

Sorry didn't realize we were talking about that new a vehicle.
Railguy

oldolds88

1. check fuel pressure

Koda

Replaced fuel filter. Had gunky brown stuff and was harder to blow through than the new one. I doubt it's been replaced in years, the flare nuts were ON THERE.

It is closer to firing. Ran fine with a shot of ether. Hooked up a fuel pressure gage. Holds 40 when off, holds 55 when ign on, cranking, and running. That's on the low end of acceptable, I read, but the behavior of starting with ether and keeping running fine, as well as some other things is pointing me at the fuel pump. It does not dive to zero when off, so I believe the injector system is ok.

Time for fuel pump, woo.

nj67

I had a '96 Suburban and I had to change the fuel pump twice, both times having same exact symptoms you are having.

bluecab

X1,
Usually they get pretty loud before they expire

oldstata

Same problem with me, except mine ended up being a sending unit ground problem. I did 3 pumps before I did the sending unit and haven't had a issue since

Koda

Thanks, gentlemen, the advice is appreciated.

Blue, it is now louder than it was, I noticed last night, and qualifies as "what the heck is that whine?" loud at the rear of the car.

Now to source the best quality for an affordable price, hah.

crzyjef

What year and which engine is it.
I had a 1996 Suburban with the vortec 350 I found that there are 2 "spider" assembly in the intake manifold.. the original or the updated it changes the fuel injection sprayers
Search for it in the "fullsizechevy.com" website..
I had to replace it .. and I found that summit.com had the best price for it. .. and be sitting down it isn't cheap.. but it did make a difference on the way it runs

Koda

98, 350, the later Vortec with the second system. CSFI. It runs like the hammers of hell, provided you get it started.

Mike77

Fuel pressure seems low. The pump for the Vortec can go bad about every 100K . The pump is cooled by the gas in the tank. If you tend to drive with low fuel a lot they fail sooner. The pressure reg go out too. There is an entire fuel pump test procedure to determine the cause of no start. Can be either the reg, injector spider leak, or the pump. Go to the recommend web site follow the test procedures.

Mike

tru-blue 442

Koda, went to start mine yesterday morning and it wouldn't. The fuel pressure sensor
on top of the intake had gone bad. Looking at the engine, it's a small black plug with a
3 wire connector that just plugs into the intake, left of the throttle body. May try that.
I put a new one in from Carquest, $44, and it fired right up and ran good.

klm57

Also on your coolant leak,check the fittings where heater hoses quick release to intake.They are white metal and disintigrate when you touch them.Very common.Usually break off even with the intake and have to easy out them to remove