zstaheli

I have a 96 12 valve and I got my boost gauges hooked up. It’s a Gloshift 100psi gauge. For some reason it’s reading that I’m only getting 10 pounds of boost! And it will only read in 4th gear. Not sure what’s wrong if that’s how it’s suppose to be. Just want some help or ideas on how to fix it. Thanks!

oliver foster

Have you checked the lower two boost tubes for tears? I have seen many 2nd gens where the inner fender rubs slashes in the lower boot tubes.

It could also be struggling for fuel..when was the last time the fuel filter was changed?

It could also just be a bad gauge.

10 PSI is low for a 12V truck at WOT in 4 th gear. My dead stock '95 makes 23 or 24 PSI.

zstaheli

Lower TWO? I’ve checked the ONE line that I have and it is fine. Also the fuel filter was just recently changed. I think it might be my gauge because I have another glow shift gauge for my pyro and it’s not working at all. Did some research and figured out the hard way that glow shift (****) gauges are horrible.

oliver foster

I have not heard much great about glowshift.

You have a lower boot on the passenger side and drivers side of the intercooler. Both are prone to getting sliced by the inner fender metal.

AlpineRAM

I'd rig up something with a tire fill gauge to test if your boost gauge is in the ballpark or not.

(Either a tee that connects the boost line to the gauge with a tire pressure gauge that you stick onto the windshield and drive a bit, or a tire filler to the boost line.. )

I don't know about glowshift, but I know in my work it pays off to check if the sensor is OK before dismantling expensive machinery..

zstaheli

I tested the gauge with an air hose with 60 psi and worked just fine. I don’t. Even checked the boost line for slack and tears. Nothing to be found. Maybe the diameter of the boost line is too small?? Not sure what’s going on. Still lost.

oliver foster

^have you check this yet?^

zstaheli

need a little more help on what it is I’m checking. Any pictures or something to help?

oliver foster

The inside of the lower fender tends cuts the lower boot.
Pretty straight forward just check that there is no cut. Just follow the boost tubes to the lower boot where in connects to the intercooler. Then check for cuts. Use a flashlight, or use you hands, whatever it takes.

zstaheli

okay sweet. I’ll let you know what I find.

zstaheli

Took a look at my boot and it’s actually metal so no worries about it being punctured. Everything down there looks good. Almost positive it’s the gauge now. Thanks for the help guys!

oliver foster

Yes, the inter cooler boost TUBES are METAL

The inter cooler BOOTS that rip are the rubbery things at both ends that are clamped in place with stainless clamps.

Check again.

AlpineRAM

Yep, the rubber pieces connect the metal pieces- so you have a rubber boot between the turbo and the pipe to the intercooler, another one between pipe and intercooler (all passenger side) and on the drivers side you have one boot from the intercooler to the pipe and one from the pipe to the intake horn. All of them and their hoseclamps need do be checked.
The gauge being verified is nice, the small diameter of the hose goes not influence the reading of the gauge. (It might make the gauge a little lazy and retard the reading of the correct pressure, but if you used the material supplied with the gauge it should be no more than 1/10th of a second of delay)

Another thing to check would be your wastegate- it might be stuck open or the spring might be broken.
An easy check for that would be to use some wire to pull the wastegate shut and go for a careful drive- if you manage to get more boost like that you have found the culprit.
(do not exceed 25 psi of boost while testing like that! )

If you do also suffer from low power, it might well be the boost reference line to the AFC, if this is broken the pump will limit output severely, "thinking" that there is no boost.

HTH