Ford Powerstroke Diesel Forum banner

4.7 Zener Diode ?

1K views 1 reply 1 participant last post by  Remington08 
#1 ·
Ok, so I am new to the Forum and powerstroke world for that matter but have been reading all the great information this site has to offer. I have been working on my new (new to me) truck doing a few things to it and have ran into a little issue I was hoping to get some info on.

I installed the TS 6 pos over the weekend and man what a difference. Turbo boost makes it to about 28 psi and then SES light comes on with overboost code. I know everybody, as well as myself knows what this is. So I previously read up on the Zener mod and had some ordered off of ebay. I installed it and re-tried. Now boost would go to 22 psi and no higher. So I got to thinking...I took my volt meter and a pressure regulator and my air compressor and set the pressure to 40psi. Ran this to the MAP sensor and it read 3.6 volts with diode in and 4.8 with it unhooked. I then set the pressure to 10 psi and it was like 2.somethin. I ran it up to 22 psi and it was 3.6 exactly where the diode limits it.

So, am I doing something wrong here? Has anybody else ran across this. I'm starting to wonder if the 4.7 diodes I got are really 4.7. I am planning to use a power supply and a resistor to check several of them to see if I can find a true 4.7.

Any info would be appreciated.
 
See less See more
#2 ·
So I checked out the diodes and they measured 4.6; so they're right. Still puzzled on why the MAP sensor is shutting off at 3.6.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top