Quick question, I don't trust the stock GT gauges on my Fiero so I bought 4 aftermarket gauges to replace them.
Oil pressure
Trans temp
Water Temp
Boost

For the oil pressure sensor I removed the stock 3800 one, and put in a T that goes to the turbo oil feed and the new sensor. Do I have to have the stock 3800 sensor too? If so what do I do with it? Does the pcm need it?

Also is that test port a good spot for the trans temp sensor? I hear it's an iffy spot.
Last question... Do I need any of the new sensors or can I splice the new gauges into the stock wiring? If so, I need a pinout. Thanks!

------------------
1987 Fiero GTX 3800 Turbo... My Build, ST3 Cam, Lowered, Wheels, and pics enjoy!//www.fiero.nl/forum/Forum1/HTML/089483.html

I too am doing a 3800 swap I have an oil cooler with a oil pressure and temp sensor and wondering if I can tee off the OEM oil pressure hole to plug in my two sensors. Do I need that OEM oil pressure sensor there? Sorry bout the hijack but no one is helping me with my build

Of those sensors the water temp is the only one the PCM looks at. You only need the Fiero sender to run the Fiero gauge. I have heard of people using T's for multiple senders, not sure it would be accurate on certain senders though. On my 4T45E i have hat the trans temp gauge where you can see the sender in this pic just to the left of the dipstick and it has seemed to work well.

Thanks mike! That's what I needed to know, and to the other poster I put a T in the stock oil port, one end for the turbo oil feed, other for the oil pressure gauge. It works great!

------------------
1987 Fiero GTX 3800 Turbo... My Build, ST3 Cam, Lowered, Wheels, and pics enjoy!//www.fiero.nl/forum/Forum1/HTML/089483.html

I like oil pressure gauges with the hollow plastic or copper tube. Im not a fan of electrical gauges. Same with temp...I like the solid core type.