Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I fell asleep in my Envoy and ran it out of gas. In waking up, i had forgotten running out of gas and started it again. I was able to turn around and totally run out....Upon gas can fill, i made it to a station and put a few more dollars in the tank. At this time check engine light was flashing indicating a misfire on cylinder 4 and it was running rough. So since the truck was running beautifully before running out of gas I figured that I may have picked something up from the bottom of the tank and plugged up an injector.... So the first thing I did was take the intake manifold off and access the fuel rail. After cleaning the injectors and putting it back together, still no start, I then went ahead and replaced the plugs, then the coils, then 5 fuel pumps, fuel filter, cam positioning sensor, then fuel pressure sensor and still no start. Im at my wits end here. WHY WONT THIS DAMN THING START? So in frustration, I decided to install a 2" body lift kit on it and cut a hole in the floor so i dont have to drop the tank anymore...... It will turn over when using starter fluid. That tells me that it isnt getting fuel, however in disconnecting the return line and cranking, im getting fuel shooting out of the FPR. So IDK... Anyone?
 

·
Registered
Joined
·
115 Posts
My oh my! Those old wives tales still run around in this age of enlightenment!

Your fuel pump ALWAYS draws fuel from the bottom of the tank. It does not have a floating pickup that follows the fuel level as it rises and falls.

How can the tank be any dirtier when its empty, than full?

1. Run a pressure AND flow test on the pump at the convenient pressure tap.
2. Do this before you merrily dive into the engine looking for ghosts and goblins.
3. Actually starting and running should be goal #1.....
4. ....... then we carefully diagnose before loading up the parts shotgun.

EDIT... with what you've done.... I'd suspect a missing injector signal.... poss CMP or CPS....but this is a long distance diagnosis... as the vehicle isn't in my shop.

Run a NOID test at least.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #6
Lol, I am having gm specific codes all pointing to the injectors. It's getting fuel but I don't believe the injectors are working... I'm fixing to get out there and pull the intake manifold of and just have a look-see... I have six other injectors, I may as well put them in if I can't find any issues. Ill let ya know
 

·
Registered
Joined
·
115 Posts
K...... can you not run an electrical injector bleed down test with a bidirectional scanner before you go to all that (possibly) unnecessary work?

No NOID tester either?

It's a lot of frustration to just dive in and start whacking parts..... when it may be a bad ground or relay somewhere.
 
1 - 7 of 7 Posts
Top