BobinAlaska

Base Silverado 4.3 Auto, 2 wheel drive. All stock, no aftermarket stereo or remote start, nothing, totally unmolested, 90,000 miles.
Power nothing crank windows, manual locks, manual seat, no cruise
The truck sat for 7 months while I was south for the winter.
The battery was not dead when I tried to start it. The battery has been fully charged after first start attempts.
It cranks fires and dies, all about that fast. And will do the exact same thing right away, time after time. Gas pedal location is irrelevant.
The passlock light acts normal. It acts the same as our 2006 Colorado. The light goes out after 20 seconds or so.
I started to do a passlock relearn but the light went out right away, not after 10 minutes like the instructions said.
any ideas?
question: If the passlock light goes out, like it should, does that totally rule out a passlock problem? In other words if the passlock light is NOT on steady then it is not a passlock problem?

I can hear the fuel pump run when I first turn the key on.
What is shutting the engine down so fast?

Thanks for reading!

cleveland63b

if it sat for 7 months untreated the first thing i'd do is drain the tank and try fresh fuel

BobinAlaska

Worth a try I guess.
Our trucks sit this long every year.
Our 2006 Colorado was parked right beside it, no problems.
I do put Stabil in the gas .

cleveland63b

I would be checking fuel delivery first either way, pressure and volume. Maybe just get a sample and see what its like

BobinAlaska

HMMMMMMMM, I just plugged in a OBD 2 code reader and NOTHING. OBD2 port is dead.
I plugged the code reader into our 06 Colorado and it works fine.
All dash lights work .

Edit: This dead OBD2 was just a fuse. Code reader now works and NO CODES.
Still has original problem, cranks, fires, dies that fast.

cleveland63b

Most OBD monitors won't even run to throw a code if its just stalling right away.

BobinAlaska

At this point I am thinking fuel pump.
I removed the fuel pump relay and put a jumper wire to make the fuel pump run all the time and it didn't make any difference.
I'm in a small town, there is one fuel pump pressure test gauge for sale for $75 or a mechanic who will come use his test gauge on monday for $60.
I used my finger and pushed the schraeder test valve on the fuel line and some gas came out but it wasn't under much pressure.
I just want to make sure it's the fuel pump, it is a $200 part and it is located in the fuel tank, not a fun job.
So Monday one way or another I will get a fuel pressure reading and go from there.

I was hoping to get more info on the passlock system, make sure that isn't a possibility but nobody here seems to know much about it .

hicksvilleshick

Mice get the wiring?

BobinAlaska

Always a possibility, porcupines are known to do that around here also.
But one of the first things I did was look over all the wiring,, I read on the internet about
wiring harness's chafing and rubbing through. But everything looks good.

cleveland63b

if the passlock light goes out and theres no code then I wouldn't be worried about it, most GM vehicles the security system disables the fuel system and some of them spark also. I'm not sure if your code reader will access the TDM though.


Any no start I touch gets fuel pressure, volume and spark tested before I even bother thinking about anything else. If you have good spark to every spark plug and the plugs are fine then in theory the distributor and crank sensor are fine also.