99 Tahoe 4x4 5.7 Vortec-Crank but wont start.

Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#1
I have a used Tahoe, 1999, with a 5.7 Vortex engine. About two weeks ago, it died on me. I assumed that it was because I ran out of fuel. Put a gal in it, still wouldn't start. Got it towed back to my house and have been trying to figure out the problem. I can hear the fuel pump kick in with the key in the On setting, as well as the fuel pump relay. I have hooked it up to a Actron OBD II PocketScan Code Reader, came back with 0 codes. Have checked fuel pressure, steady at 60psi with key on. I've already changed out the fuel pump relay, and prepairing to change out the fuel filter, even though I'm fairly sure its not a fuel system problem due to fuel pressure. I put about a 1/4 cup of gas directly into the throttlebody, still wont even try to start. It cranks, but just wont start.

I've about exhausted my limited knowledge of this, thus reaching out for help.
 
Joined
Mar 1, 2002
Messages
3,401
Likes
43
Points
48
Location
Kentucky
#2
Do you know how to check for spark? Does your vehicle have an external coil and coil wire?


After multiple attempts to start, is there a fuel odor at the tail pipe? Wind matters.
 
Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#3
I'll be checking the plugs in the morning, have a light up tester for it.

I've noticed a fuel odor, after a couple times trying to start it, but couldnt say if it was from the tailpipe or not, will confirm in the AM.

It is coil, sits on the back top area of the engine, so I assume its external?
 
Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#5
Ok, pulled the plugs, all but cylinder 4 and 5 were wet, not damp, but SOAKED. The plugs looked to be original plugs from when the truck was first built, so even if it isnt the problem, they needed to be changed.

as to the coil, I think it might be internal, as I do not see that part in the picture that you indicate, but I also dont see a distributor. All my plug wires run into a plastic flat box, 4 per side, that sits just under the plastic air housing, on the top/back side of the engine.
 
Joined
Mar 1, 2002
Messages
3,401
Likes
43
Points
48
Location
Kentucky
#6
Have you tested for spark? Or, to be even more direct; is your ignition system producing high voltage to spark plugs when cranking? Got spark?

Are you sure the flat plastic box doesn't look like this, with places for 5 wires on one side?
 
Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#7
I replaced all the spark plugs. Turned the key and same as before, cranks but wont fire. Pulled the plug out of #3 and its wet now too. Tried cranking it with the plug in the wire, but out of the cylinder, not getting spark, but that may be because its wet?
 
Joined
Mar 1, 2002
Messages
3,401
Likes
43
Points
48
Location
Kentucky
#8
You said, "I'll be checking the plugs in the morning, have a light up tester for it." Tell me more about that tester. Does it look like one of the testers in the pic I posted? A spark tester would probably be more reliable than a wet spark plug.
 
Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#9
yeah, its a light up tester, plug into the plug with a cap to go on the spark plug. Kinda looks like the one in the bottom of that picture, but older.Not sure if the tester is good, its someone else's so dont want to tinker with it too much. I did test the old plugs with it, #1, #3, and #5, light did not come on, didnt test the others but after the amount of build-up I found on the old plugs, I figured it wasnt going to make a difference and just figured on changing them all out. As I said, they appear to be the original plugs. Have not tried it yet with the new plugs. Should I try it with wet plugs or some I let em dry out first and then test with it?

Your last picture is what I've got in my truck. Is that the distributor? I'm used to ones that look like a cylinder with a cap on the top of it.
 
Joined
Mar 1, 2002
Messages
3,401
Likes
43
Points
48
Location
Kentucky
#10
That is a pic of the distributor cap. If there are five wires on one side you must have an external coil and we need to test to see if the coil is working and sending "spark" to the distributor cap.
 
Joined
Mar 1, 2002
Messages
3,401
Likes
43
Points
48
Location
Kentucky
#12
If we put a clockface on your pic, the coil would be at 9 oclock. Coil wire comes out the top, bent over and going down to the rear of the distributor cap.

These posts may soon show up on a "page 2". Don't be fooled by the transition.
 
Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#13
Ok, so I traced the C cable coming off the distributor, it runs into that plug, from my picture, that is at the 9oclock position. Its the same unit that the yellow plastic plug is going into as well.
 
Joined
Mar 1, 2002
Messages
3,401
Likes
43
Points
48
Location
Kentucky
#14
Do you have another vehicle that you could test your spark tester with? Our first goal would be to test to see if the coil is working and sending "spark" to the distributor cap. Since coil wire failure is common on these vehicles, it would be best to remove coil wire from coil and test at that point.

And I gotta ask...do you have a helper? because it makes testing WAY easier.
 
Joined
Oct 26, 2013
Messages
21
Likes
0
Points
0
#15
Spark tester works. Hooked it up to my 04 Grand am between the distributor and the plug wires, flashed in time to cylinder.

Wife turned the key for me. :)

This spark tester does not connect to coil plug though, just tried it.