I installed the PLX gauge a lil bit ago. When I start the truck and give it a little throttle, the gauge is reading 18-21. that is obviously wayyyy off! I'm not sure if I got it installed wrong or what the deal is? I have the vac line going from the small barb on the back of the blower manifold directly to the PLX module. When I remove the vac line from the module, i can feel it flowing air out so its definetly getting some sort of reading.

Also, the LEDs that scroll around the gauge (green, yellow, red) aren't lighting up, so I don't know if that matters or what? They light up in a scrolling pattern when I start the truck, but I think that's just a normal sequence.

Just want to make sure I didn't screw something up or miss something that was blatantly obvious.

Anyone with know-how on these specific gauges, please chime in!

Thanks in advance!

 

Robbie, is this the only module your running on the truck?
Do you have a PLX wideband setup?

 

yep, got a PLX wideband too, works perfect.

I should add that I do not have them daisy-chained, they are setup as stand alone.

 

I would make sure the module has a good power supply and ground. And make sure the gauge is connected to the TX slot on the module.

You may have to install the hose elsewhere as well.
I know some of the older trucks tap into the hose running to the FPR, im not sure whats the best place to tap in for your 06.
I would PM BlownChevy and ask him.

 

the +/- is good, made sure of that. I am leading to believe its where the vac line is hooked in to. I don't have any taps handy otherwise I'd explore some other options. Grrrrr!!!

 

anyone else?

 

Heh! You are seeing vacuum when you start up. This is indicated by no LED display.
LED displayed indicated pressure, no LED you have vacuum.

Read page 3 here.

Heh! I don't know who writes PLX technical documents but its the most scattered, covered and smothered stuff I have ever seen. Good thing for them its a good product.

 

Where do you have the boost/vac line plugged in? If it is plugged into the J-tube that will read vac only, you need to plug it into the 1/8 nipple on the back of the manifold UNDER the J-Tube.

 

I had thought about that and I guess I should go take it down the street and hammer the gas to see a reading. Thank you for the input!

On the manifold itself, not the Jtube. Just below the Jtube, near the MAP sensor (I believe?). There is a 1/8" NPT threaded piece coming up and then a small barb right next to it. I was told either one would be sufficient to get the boost psi out of, so I capped the NPT and hooked up the vac line on the barb. It's pretty tight fit, I can yank on it and it doesn't give, so it feels as though its sealed pretty well?

 

18-21 hg-in vacuum is normal, sounds like it's working correctly to me. What do you see when you're in boost?