2007 Nbs Disable Fuel Or Ignition?

e.p. · December 31, 2010

Hi;

Can anyone tell me which fuse or relay I can pull to disable the fuel pump or ignition on my truck??? I like to be able to crank the engine over until I see oil pressure after an oil change. I've pulled the fuel pump relay and fuse out from the engine compartment fuse block but the truck keeps running. I would pull the relay for the fuel pump on my 99 Silverado while it was running and it would quit after a short time. Anyone know????

Thanks.

Ape0r · January 1, 2011

Why go to all that trouble? If you're concerned about it, just fill the new filter with oil and it'll pick up pressure almost immediately.

What are you worried about? Just double check that you've replaced the plug and filter, and poured in the new oil!

e.p. · January 1, 2011

Hi;

I do fill the filter with oil. Even so, when Its started there is no oil pressure for a short time. Maybe it doesn't hurt anything but I just don't like seeing the oil pressure gauge at zero. I've always primed the oil in every vehicle I've had.

Silverado4x4 · January 1, 2011

Dont worry about it, your not going to hurt anything.

tunseeker1 · January 1, 2011

Cranking the engine over with no oil is the same as running it with no oil.

Ape0r · January 1, 2011

Cranking the engine over with no oil is the same as running it with no oil.

+1. Your practice only changes the kill mechanism if you don't see oil pressure in satisfactory time; instead of just turning the key off, you have the option to kill it by releasing the key.

That said, I put a kill switch on the fuel pump relay in the underhood fuse block on my 2004. The engine will, however, still start before it sputters out.

My advice is to find something more pressing to worry about.. like the chances that a bolt of lightning will kill you on a sunny day.

Silverado4x4 · January 1, 2011

Jezzz whats the differance in cranking the engine to see oil pressure after a oil change or just starting it up and getting oil pressure, its still the same thing the engine is still turning over. As said dont worry about it. Plus I dont think the gauge works in crank mode.

SouthCo · January 1, 2011

Jezzz whats the differance in cranking the engine to see oil pressure after a oil change or just starting it up and getting oil pressure, its still the same thing the engine is still turning over. As said dont worry about it.

I was thinking the same thing. And it's not like the engine is completely void of oil after you drain the old stuff out. Everything is still coated. But if that is your thing, sorry I have no idea on how to disable fuel or ignition.

Ape0r · January 1, 2011

Jezzz whats the differance in cranking the engine to see oil pressure after a oil change or just starting it up and getting oil pressure, its still the same thing the engine is still turning over. As said dont worry about it. Plus I dont think the gauge works in crank mode.

Not sure about my truck, but my 92 corvette shows oil pressure when cranking long enough for it to build pressure (car refuses to start FREQUENTLY).

txab · January 1, 2011

Hi;
Can anyone tell me which fuse or relay I can pull to disable the fuel pump or ignition on my truck??? I like to be able to crank the engine over until I see oil pressure after an oil change. I've pulled the fuel pump relay and fuse out from the engine compartment fuse block but the truck keeps running. I would pull the relay for the fuel pump on my 99 Silverado while it was running and it would quit after a short time. Anyone know????

Thanks.

You can download a copy of your manual here.

Follow the instructions.

Then you'll know which fuse or relay.

IMHO your method is overkill, but to each his own....

LeoS41280 · January 2, 2011

I was wondering will pulling a fuse or relay to disable the fuel pump or ignition set a code?

e.p. · January 2, 2011

Hi;

I had to pull two fuses for the left and right side fuel injectors and ignition coils. The oil pressure gauge does not show pressure when the engine is cranking but it will jump up when you stop cranking the engine. Also, the computer will keep cranking the engine for a couple of seconds even when you leave off the key. Ya, maybe its something that does not need to be done but I prefer to do it.

blacksierra01 · January 2, 2011

shouldnt holding the throttle at WOT (wide open throttle) while cranking not allow the engine to start? I know it did on some of the older fuel injection systems, but havent tried it with the new stuff.

c4cruiser · January 2, 2011

Even after draining the oil out and refilling, then installing a new filter, there will still be oil left in all the crank journals, the cam bearings, lifters and every other bearing surface that gets oil under pressure.

If you pre-fill the filter and install it, it will take about 2-3 seconds for the oil pressure gauge to move. That amount of time will not hurt anything that is pressure lubed by the oiling system. While the gauge is electric, the movement of the needle is still mechanical. By the time the needle has moved, the oil pressure sender signal has reached the PCM and a signal is then sent to the gauge. There is already oil pressure by the time the needle moves.