Digital Boost gauge install help

[agentorange313]

A couple of days ago I posted a thread about how to wire up digital boost gauge to the battery.

I have gotten though all the wiring with the fused and etc. It is a AEM digital boost gauge. Not the Boost controller. It has one port for the pressure sensor, just like any other gauge.

The problem I am having is that on my 91 eagle talon has no fuel pressure solenoid. The fuel pressure regulator vacuum line is connected to the intake manifold.

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After reviewing the Taboo speed racing diagrams I have found that the way you install a boost gauge without a solenoid is to put a T between the vacuum line from the FPR to the intake manifold.

I installed the boost gauge, power all good, but the only reading I am getting from the boost gauge is -20,-18. Am I supposed to install the T from somewhere else? Why is it reading -20,18?


Thanks

 

[EvoRage]

this might sound stupid, but have you tried to get into boost? it will read negative at idle due to it pulling a vacuum.

 

[cds1320]

ya try going into boost or even just tapping the gas it should change. its not gonna read boost untill you can hit boost.

 

[agentorange313]

yea I just took it out for a drive just now. The I even took out my manual boost controller and hooked up the the lien from the boost source to the stock wastegate, to run stock boost. 14b. it is still reading -18/-20

 

[cds1320]

there might be a problem with the solenoid what does it read if you dont have it plugged into anything?

 

[agentorange313]

I unplugged the sensor from the solenoid and the reading was -.-- across the gauge, meaning no reading for boost.

Then I unplugged the nipple form the boost source line and plugged the sensor back into the solenoid and the reading was -18,-20 again.

Update:

I just read on a scion forum thread, that had the same diagnosis as I did, that the AEM sensor could be faulty if it is reading vacuum when there is none.
This is what they wrote:

"I spoke with AEM tech support and they told me that if the gauge is off in vacuum, it's off in boost too. So when I saw 6psi, it was really 8psi, that's flippin' great... Anyway, I got a RMA # and have to ship them the gauge and sensor so they can check them and replace the defective sensor. They told me they had a bad batch of sensors. Apparently the stainless sensors are questionable and the brass ones are okay.

Good thing I paid big bucks for a quality brand name that probably gets their stuff made in China. At least they seem to have good customer support, although they didn't even offer to send me a shipping label.

FYI, AEM emailed me today to let me know that they tested my gauge and found the sensor to be faulty. They're sending my gauge back with a new sensor. If you have an AEM boost gauge and it read anything but zero with the engine off, it is probably off by the same amount throughout it's scale."

I have the brass sensor, so I am going to call AEM on monday to see if I can get this problem resolved.

 

[agentorange313]

NEW UPDATE:

I called aem today about my gauge. This guy Henry Schelley helped me out. Amazing guy and great costumer service. They are sending me a new sensor for the boost gauge. It was a 200 dollar boost gauge, worth ever penny.

I guess the 200 covers the best customer service for performance parts.