99 Tahoe No Start Flooded?

[Bobby99]

Hi Guys new to the forum and need a little help.

I have a 99 tahoe 5.7. Truck was sitting for a few days because I needed to change the starter. The starter drive was sticking after the truck started. My wife started the truck and moved it about 20 feet and shut it off to sweep up the leaves. When she tried to start it to move it back into the spot the starter wouldn't engage, just kept making that grinding noise. I came home from work got it start and it seemed like it had loaded up with gas . Blew smoke for a few minutes until it cleared up. I drove it around for about 10 minutes and parked it. Started up fine but with the starter noise. Told her to leave it until I could change the starter.
A few days later, I tried to start it to get it on the driveway so I could change the starter.Couldn't get it to crank very well even with a battery charger on 250 amp boost. It would almost turn over then puffr white smoke back through the air cleaner housing. Smelled alot of gas so I pulled the plugs. They were soaked with gas. Cleaned them and gapped them. They are platinum plugs BTW and only about 1 year old. Checked spark and it has a good storng spark. Tried again to start it and still wouldn't turn over. It sat for about another week until today. I replaced the starter, brand new not rebuilt. Changed the battery, brand new die-hard. Tried starting it and it cranks strong sounds like it wants to start but won't. Strong smell of gas again and plugs soaked. Still has good strong spark.
I remember years back when I worked in a body shop we sometimes had problems with cars flooding from starting them and turning them off w/o them ever warming up or being driven. Changing the plugs was always the cure.
So I'm thinking I need to throw a set of plugs in anyway. But I wanted some other opinions. Am I missing something? DIs it a common problem with these tahoes? It now has 98,000 miles and I have it from new with few problems other than a fuel pump and harness a few years back.
Sorry for the long post. I wanted to give as much infoas possible. Thanks for helping.

 

[lookout]

hi my 99 tahoe is doing the same thing i think it is the ignition module in the distributor or the pick ups in the dist. try that it is about 80 $$

 

[Bobby99]

thanks

Well I tried a new set of platinum plugs today and it still won't start. Stumbled a few times like it was almost going to start but not quite. Anyway hooked up my scan tool and got a code P0338 crank sensor voltage high. So I guess next step is to replace crank sensor. Sounds like that could be the problem, I guess. I have spark but maybe not at the right time. That could be why it stumbles and kinda feels like it might almost start.

To add insult to injury....we had a few inches of snow laast night and when I went out this morning I found parts of a Lincoln Town Car stuck on my rear bumper pad and more parts of its grille, lights, and header panel all around the back of the truck. So now I have a small bend on the lower left 1/4 panel and a small gash in my bumper impact strip. At least it looks like my tahoe won that fight!:smilielol:

 

[lookout]

so a code came up that it was the crank sensor? not the module? mine is doing the same thing, it cranks good trys to start but wont then when you cut the key off it blows back thru the throttle body. guess i need a code check on mine too. thanks for the info and merry christmas

 

[Bobby99]

Hi Lookout
Yeah funny thing is I used a memory saver before disconnecting the battery to replace the starter. After swapping out the starter and battery, I tried the scan tool when it still wouldn't start but it showed no active or pending DTC's. I assumed the plugs were too soaked with gas for it to start. So I changed the plugs too. After it still wouldn't start, I tried the scan tool again and got 1 DTC, P0338. It also said MIL Not Requested. So that's why no check engine light. So then I wondered why I didn't have that code before and looked at I/M Readiness and that said 5 Incompletes. So that means either my first battery was run down so much from trying to start the truck that I lost stored memory or that my memory saver didn't work.
Anyway its raining pretty steadily out right now so the sensor will have to wait. Hopefully that solves the problem. I'll let you know.
Thanks for the help and Have A Merry Christmas!

 

[Bobby99]

Changed the crank sensor today and still have the same problem and symptoms. Engine is still flooded. Don't have a fuel pressure gauge, but when I depress the schraeder valve fuel squirts up. I'm starting to think that from the truck sitting the fuel system lost pressure and I'm not getting enough pressure for it to start only enough to flood the engine. Took off the distributor cap. Cap and rotor looked OK and were dry, no moisture. Plugs have spark.
Anybody? Any ideas?

 

[peterey2]

i can get u a trouble tree (a list of things to diagnose to solve yer problem VIA yer trouble code) i'll send u the link thru a PM.

 

[lookout]

Changed the crank sensor today and still have the same problem and symptoms. Engine is still flooded. Don't have a fuel pressure gauge, but when I depress the schraeder valve fuel squirts up. I'm starting to think that from the truck sitting the fuel system lost pressure and I'm not getting enough pressure for it to start only enough to flood the engine. Took off the distributor cap. Cap and rotor looked OK and were dry, no moisture. Plugs have spark.
Anybody? Any ideas?

hey bobby how about the ignition module in the distributor? thats all thats left youve changed everything else

 

[Bobby99]

Hi Lookout
I think the module is OK since I have spark. Right?
Someone else suggested it could be low fuel pressure, a bad pressure regulator, or leaking injectors.
The whole thing is just strange. Yeah I know things break. But the truck ran good until I let it sit for about a week waiting to put a starter in it.

 

[mckinlyjoe]

I have a 99 tahoe and have been having the same issues....replaced cap/rotor, fuel pump...problem comes and goes...one second runnign fine next doesn't start just cranks and cranks but then will misre or ht like 2 seprate cylanders ar going at the same tim....i just replaced cap and rotor today....it started up but was still running rough not so much at higher rpm but at lower idle..turned on and off like ten times still bad idle...drove with bad idle to friends aroundcorner...turned off truck went inside and complained cae out ran like new.....so it wasnt fuel pump or cap and rotor..hope that helps you.

 

[Bobby99]

Took a fuel pressure reading. 62 psi while cranking. Release key to run position drops to 58 psi. Repeat theses steps a few times cranking always 62 psi and lowest reading when left in run position is about 55/56 psi and it holds steady. Turn the ignition off, pressure goes back to 62 psi and holds steady.
So pressure looks good, right? Have spark and good fuel pressure but still won't fire and plugs soaked with fuel. Now what?

 

[bsamoul]

Are the cylinders full of gas now too?

 

[Bobby99]

I wouldn't say "full" of gas but the plugs are wet with fuel and if I remove them and tap them into my palm for example I get a small wet spot on my hand.

 

[brodg]

if you have spark compression and the timing is ok the only thing left is a clogged exhaust. try unbolting the y pipe and see if it starts. converter is probobly clogged.

 

[brodg]

also put some fuel in a bottle see if it is contaminated. it will seperate

 

[Bobby99]

I can feel the exhaust coming out of the pipe when someone else is cranking it.
I also disconnected the fuel pump, dried the plugs and tried spraying carb cleaner into the throttle body still won't fire. In the past when the fuel pump went bad I was able to get the truck into my driveway by laying under the hood spraying carb cleaner into the throttle body while my wife drove.

 

[lookout]

hey bobby i think we have spark in our tahoes but it is misfire (not in order)due to the m the module. i think i am gonna change the module in mine. i am out of town working so i wont get back to mine for about 3 weeks. le me know how yours works out

 

[brodg]

heres a real stupid thought you didnt happen to get a faulty starter motor and the engine is cranking in the wrong direction? something easy to check

 

[Bobby99]

Well speaking of "stupid thoughts", I thought about it for awhile .....it has fuel and it has spark....like someone mentioned above what about timing? It wasn't cranking real easy like a jumped chain so I kinda ignored that idea. Then I figured just for giggles let me try a new cap and rotor. Sounds too simple, right? Well I changed the cap/rotor, touched the key and started right up! Smoked like hell and the converter smelled like burning cotton candy for a little while and then it cleared out, but it's alive!

Thanks for all your help guys!

 

[lookout]

thanks bobby i guess i wil change mine also and see if it starts. how much was the cap and rotor??