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Crank no start.

Dieseldude69

Dieseldude69

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92 Sierra 3500

I replaced the passenger side injectors on my truck then when I went to turn it on to check that I had completed the job it started and ran rough for about 5-10 seconds then died. I filled the fuel filter bowl with fuel and tried again. Same result. Occasionally the truck will suck in air on a cold start but it only started doing that recently. I heard it could be a seal or valve in the injection pump, a bad valve in the pump under the cab letting the fuel flow back to the tank or a cracked line letting air in. The fuel in the bowl will run out if I crank the engine even if it doesn’t try to start and there’s no sign of leaking fuel that I can see. When I jump the in-line pump to power while the truck is off to fill the bowl bubbles come out of the fuel feed and once the fuel level is above the top of the fuel feed it will drain down to where it will no longer spill over into the fuel feed. It ran nicely before and I’m trying to get in running again so I can trade it for a 6.2 suburban.
 

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Replace the 1/4” fuel line coming out the front of the ip with clear tubing. When you see bubbles flowing that tells you there is air intrusion.

When changing injectors it is normal to require bleeding the air out by having the line nut loose at the injector until it starts spitting out fuel, then snug them up. Same procedure for air trapped in the system and it won’t start.

If you run a jumper wire to the lift pump you can use it to feed the fuel to help fight the hard start while bleeding. Also you can leave it on for a while (with engine off) while you search for a possible leak. I suggest doing this because many people assume they have a working lift pump because of the noise when the flap seals that move the fuel are actually worn out- so it makes noise but no fuel being pushed
 
Is the fuel tank full?
I have to ask because there were a lot of instances that people have run out of fuel or only have 1/4 of a tank which is not enough for this truck.

Next, what kind of LP is there? If it is electrical, you need to put 12V direct to the LP and keep it running while you are cranking.
It will take a rather long crank time so make sure you pause to cool down the starter.
 
JMJNet said:
Is the fuel tank full?
I have to ask because there were a lot of instances that people have run out of fuel or only have 1/4 of a tank which is not enough for this truck.
Click to expand...
Yeah, when the fuel gauge gets close to the red marks at the bottom of the gauge on My truck, it is out of fuel.
 
JMJNet said:
Is the fuel tank full?
I have to ask because there were a lot of instances that people have run out of fuel or only have 1/4 of a tank which is not enough for this truck.

Next, what kind of LP is there? If it is electrical, you need to put 12V direct to the LP and keep it running while you are cranking.
It will take a rather long crank time so make sure you pause to cool down the starter.
Click to expand...
So I would need to have someone hold the Lp fuse to power while cranking to get it to keep pushing the air out of the system?
 
Will L. said:
Replace the 1/4” fuel line coming out the front of the ip with clear tubing. When you see bubbles flowing that tells you there is air intrusion.

When changing injectors it is normal to require bleeding the air out by having the line nut loose at the injector until it starts spitting out fuel, then snug them up. Same procedure for air trapped in the system and it won’t start.

If you run a jumper wire to the lift pump you can use it to feed the fuel to help fight the hard start while bleeding. Also you can leave it on for a while (with engine off) while you search for a possible leak. I suggest doing this because many people assume they have a working lift pump because of the noise when the flap seals that move the fuel are actually worn out- so it makes noise but no fuel being pushed
Click to expand...
I jumper the Lp and fill the fuel filter bowl so I know the pump is operational but idk if it’s running while cranking
 
pull the hose off the ip with the LP running and then when you feel like the air is out push it back on and turn off LP. Messy but effective.
 
You can do that with the return line but shouldn’t have to. The return line nan handle a descent amount of air in it
This video shows a tremendous amount of air in the system. It was so bad the driver had his foot to the floor just to keep iit running. Once he installed ew fuel line pre lift pump, it ran perfect. This was the worst I’ve ever seen ans still ran.
 
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