2017 GMC in tank pump Walbro 525

[HellKnightHicks]

The in tank fuel pump can't keep up with the LT4 injectors and hpfp.

Upgrading to the Walbro 525 wondering if anyone has adjusted there pwm tables for the hellcat pump?

If so please share.

The current beta will not allow me to cycpe threw all of the unit options. Pulse per minute is what I think makes the most senss.

But I'm sure the 525 wont need to run nearly as hard as the stock pump did.

I guess I'll install and log. Then lower the ppm by 25%

Or if it holds the right pressure I'll just leave it alone.

These new fuel systems are non return so it may be interesting.

[HellKnightHicks]

I've taken photos of the wiring and needed bucket modifications and may make a video. Haven't decided yet.

[TheMechanic]

I would be interested in seeing that.

[MORLOK]

I ran the hellcat pump for a while. Seemed to operate fine with stock parameters. But twice, twice!, on startup, it blew the hose connection off the top of the fuel pump leaving me stranded. Part of this was from me using a standard fuel hose and hose clamp, but I also wondered if the new pump overshot the pressure target and blew the hose off. It only happened at startup.
I didn't really need the hellcat pump, so I swapped it out to save the trouble, but I am upgrading fuel system again and will need it this time.

I have the latest beta and don't see the 'pulse per minute' table you are talking about in a 2017 Silverado file I have.
It might be worth it to lower the base DC table by 20% or so to compensate for the larger pump. (under fuel system > fuel pump)

[HellKnightHicks]

2022-01-10 21_22_34-Window.png
The units dont show anymore because I cycled threw the different types and it just stops with no unit type listed.

Good to know about the top hose on the pump blowing off.

How did you mount your pump. Did you totally ditch the bucket?

I currently have my Fuel System Voltage Min bumped up a bit to try and help the stock pump keep up.

That table says minimum. Does it actually control the pumps power input?

[MORLOK]

That is the table I was talking about. I don't know if it will make a difference or not(or if any of the fuel pump minimum tables do anything). Just maybe at startup. But since we can't seem to change any of the PID parameters for the low side pump I think the computer just figures it out. My builder has run these pumps in a few trucks without changing the tune and they seem to run fine.

I still used the bucket. It wont push up to engage the clips, but I drill a small hole through the plastic and run a couple rivets to keep it together. On my latest build I also switched to a plastic style hose (like the stock one) that will hopefully grab the barbs better and stay on. I also twisted a wire around the connection to help hold it better.

[TheMechanic]

I ran the hellcat pump for a while. Seemed to operate fine with stock parameters. But twice, twice!, on startup, it blew the hose connection off the top of the fuel pump leaving me stranded. Part of this was from me using a standard fuel hose and hose clamp, but I also wondered if the new pump overshot the pressure target and blew the hose off. It only happened at startup.
I didn't really need the hellcat pump, so I swapped it out to save the trouble, but I am upgrading fuel system again and will need it this time.

I have the latest beta and don't see the 'pulse per minute' table you are talking about in a 2017 Silverado file I have.
It might be worth it to lower the base DC table by 20% or so to compensate for the larger pump. (under fuel system > fuel pump)

Funny you mention that. GM used to put an inline "Pulse Eliminator" in the fuel system. Don't think it was for the issue of hose blowoff but it was a diaphragm that reduced pump pulsations that was used to reduce injector errors.

[HellKnightHicks]

That is the table I was talking about. I don't know if it will make a difference or not(or if any of the fuel pump minimum tables do anything). Just maybe at startup. But since we can't seem to change any of the PID parameters for the low side pump I think the computer just figures it out. My builder has run these pumps in a few trucks without changing the tune and they seem to run fine.

I still used the bucket. It wont push up to engage the clips, but I drill a small hole through the plastic and run a couple rivets to keep it together. On my latest build I also switched to a plastic style hose (like the stock one) that will hopefully grab the barbs better and stay on. I also twisted a wire around the connection to help hold it better.

Thats what I thought. The FPCM and the ECU Will slow the pump down to get the desired pressure at the rail. I think those tables are base reference then the system figures it out after that. But again these are just assumptions. A good log will show the difference.

I cut the bottom of the bucket out except for the areas for the feet and syphon griddles (cant think of a better term for it).

the hellcat pump sticks our the bottom about 11/16 out the bottom. Im looking for some screw caps that are fuel resistant.
Pump Bucket.jpg

Did you lube the hose before sliding it on or just push it on?
Maybe take some sane paper and grab and twist the mating nipples then spray some air and use some alcohol to clean the surfaces if the hose is blowing off. Did you use hose clamps?

[MORLOK]

Here is my setup.

The barb connection on the bucket is just not very good for grabbing a rubber hose. You can see the rivet for the bucket, I have another on the back.
I think the 'pulse eliminator' might be the diaphragm shaped part built into the assembly.
I warmed up the plastic tube to slide it on and then twisted the wire around it to help hold it on.
I thought about using hair spray last time, it works as a good lube, and then when it dries is acts like glue.

20220109_035942619_iOS2.jpg

[HellKnightHicks]

Hum interesting so you didn't cut the bottom of the bucket out. Were you able to keep the venture syphon system at the bottom of that bucket?

Have you had any issues with fuel level indication? or fuel not able to enter the bucket at lower tank levels? I would assume not given that the bucket will be sitting in the same place.

The hair spray thing is a pretty good idea.

[HellKnightHicks]

DeatWorks makes a pump thats drop in. Im probably going to grab that as I dont want to lose the Emtpy tank syphoning ability. Never finished the job of putting the Hellcat Pump in.

[tfrost92]

Were you able to run a strainer/sock on the bottom of the pump without cutting the bottom of the basket?