View Full Version : Switched over to gen3 electronics but boost gauge is dead now

08-23-2017, 03:57 AM
So I installed the gen3 efi on my gen3 engine and it fires up and drives great but my stock boost gauge isn't reading at all now????
I'm using a berk gen2 to gen3 patch harness.
While I'm cruising the AFR's jump from 14.7 down to 14 back and forth and when I build boost, my afr's go down to 12.5 with roughly 80% of my gas pedal down and 10.0 - 10.5 at WOT
It runs great besides the afr's bouncing around a little.
Any ideas on how to get my stock boost gauge to read properly?

I tried my gen2 map sensor and it also doesn't make the gauge work.
The PO had the CEL bulb removed because it doesn't light up so I can't check for codes. I need to figure out (again) how to open it up so i can fix that bulb so I can check for codes

08-23-2017, 06:38 PM
Why not just run an aftermarket boost gauge? The stock one doesn't tell you anything anyway.

08-23-2017, 08:10 PM
The PO took out the bulb and bulb holder for the CEL light. I just pulled the bulb/holder from the cruise control since the P.O. also removed that system.....
I'm getting code 52 and the usual code 54 since im using a st205 ecu. I know code 52 is for the knock sensor but I've been up to 7psi and 5000 rpm since I got the car on my little test drives around where I live and I haven't had any driving issues so I don't think it's in limp mode.
Any ideas?

08-23-2017, 09:25 PM
Why not just run an aftermarket boost gauge? The stock one doesn't tell you anything anyway.

I have one already but I'm worried the ecu isn't reading the turbo pressure. I like everything working. I get picky with sh** like this ;)

08-23-2017, 09:32 PM
I just looked and my knock sensor isn't plugged in. To make things worse, I don t see the damn wire/plug for it!
I see a plug/wire for what I think was the tvis but that's it in that area. I'm tempted to connect my antilag vacuum thingy since it has a similar plug but something would probably go wrong ;) (yes, I gotz that homo engine :) )
Anyone anyone know where the knock sensor wire comes out of the main harness? I'll look for now

08-24-2017, 04:32 PM
Found the (cut) wire..... It only comes out of the harness a few inches and now i need a pigtail and connector

08-26-2017, 07:06 PM
If the MAP sensor isn't sending a signal to the ECU, you're going to know. It will run like@#$!. I know from when I did my conversion. I built an adapter harness to start with and got some of the resistors hooked up backwards. The ECU was getting massive back signal and it just dumped fuel. Your car sounds like it is running good so I would say that the MAP sensor is reading the boost pressure fine.

I'd say that the stock boost gauge isn't working because the of the differences in the MAP sensor voltages and the way the ECU reads them. I would hook up the aftermarket gauge so you can see what kind of boost you're actually getting. That will tell you a lot.