Fuel gage/interesting setup/need advice.

[Astro]

Hey all,

So some similar threads have been posted about this, but mine is a little more specific and I want to see if anyone out there has messed with this.

I have a 1996.
1998 fuel pump/sending unit/tank.
2001 express van 0411 PCM.

Stock setup with sending unit wired to gage didn't work. gage read way past full.

Ran sending unit wire through Red pin 54 and ran output to gage from Red pin 38. Still reading all screwed up, but definitely different lol. Different in that it was a little less than with the gage directly connected.

I've read that this may have something to do with Ohms being different on the sending units based on years, but I'm not exactly sure what I have to adjust in the volume tables in HPTuners.

Have any of you done this successfully with my setup? Does anyone know how each parameter affects output on the gage?

Attached are the parameters you can adjust in HpTuners.

 

[Schurkey]

Perhaps a moderator will move this thread to the 96+ Vortec Performance + Computer Swaps sub-forum.

 

[Astro]

Oh dang, I used the wrong section!

Perhaps a moderator will move this thread to the 96+ Vortec Performance + Computer Swaps sub-forum.

 

[BeXtreme]

Hey all,

So some similar threads have been posted about this, but mine is a little more specific and I want to see if anyone out there has messed with this.

I have a 1996.
1998 fuel pump/sending unit/tank.
2001 express van 0411 PCM.

Stock setup with sending unit wired to gage didn't work. gage read way past full.

Ran sending unit wire through Red pin 54 and ran output to gage from Red pin 38. Still reading all screwed up, but definitely different lol. Different in that it was a little less than with the gage directly connected.

I've read that this may have something to do with Ohms being different on the sending units based on years, but I'm not exactly sure what I have to adjust in the volume tables in HPTuners.

Have any of you done this successfully with my setup? Does anyone know how each parameter affects output on the gage?

Attached are the parameters you can adjust in HpTuners.

From what I know, your factory 1996 sending unit would have had the 0-90ohm sending unit. The 98 has a 40-240 ohm sending unit. The express van values should be right for the 40-240 ohm one. You will need to enable PWM and set the output frequency to ~140hz to get a smooth value going out. Then see what the gauge does. If it is still maxed out, you probably have the values backwards in the fuel gauge output vs level table. Heres a thread with posted values that seemed to work for someone else with a similar setup.
https://www.gmt400.com/threads/hooking-up-97-fuel-gauge-to-12200411-pcm.36855/

 

[Astro]

From what I know, your factory 1996 sending unit would have had the 0-90ohm sending unit. The 98 has a 40-240 ohm sending unit. The express van values should be right for the 40-240 ohm one. You will need to enable PWM and set the output frequency to ~140hz to get a smooth value going out. Then see what the gauge does. If it is still maxed out, you probably have the values backwards in the fuel gauge output vs level table. Heres a thread with posted values that seemed to work for someone else with a similar setup.
https://www.gmt400.com/threads/hooking-up-97-fuel-gauge-to-12200411-pcm.36855/

Thanks for the reply!

You're exactly right lol. I ended up doing just that. I had to invert the fuel gage values and take the primary volume table from a 98 silverado and that made it work perfectly.

 

[BeXtreme]

Thanks for the reply!

You're exactly right lol. I ended up doing just that. I had to invert the fuel gage values and take the primary volume table from a 98 silverado and that made it work perfectly.

Great news. I'm hoping to do this on older swap too. I'm putting an L29 with an 0411 swap into my 1980 K25 pickup and was hoping I can wire the sender into the ECU and then drive the OEM gauge. I hadn't seen much about this on the 97-earlier analog gauges, so I wasn't sure if it would work right(still might not).

 

[Astro]

After driving it around a bit, I still get a little erroneous movement on the needle. I had then pwm set to 240hz at som point and it was dead still, but lowered it to 140 because I wasn't sure what the circuit could handle.

You should be able to do it. The whole thing will be trying to figure out the tables and I know someone out there knows the math on it, but I'm not sure where to find it dang it. It would be nice to know to really dial everything in.

I would love an L29!