Hey Guys
I've recently purchased an FD with lots of mods. I've recently noticed that the Profec B that's installed isn't doing anything to regulate boost. My car boosts to about 10-12psi no matter what I do to the dials on the controller. It's got a Pettit ECU in it, but I believe the Greddy should override correct?

Am I simply seeing waste gate pressure? Where should I start my troubleshooting? Does anyone have a similar thread saved they can direct me to?

Thank You Very Much

 

might need the wastegate ported. it also depends how the boost controller was hooked up plumbing-wise

 

Are you trying to run more boost or less

 

It helps to list all mods your aware of.

 

It shouldn't be a wastegate pressure because then it should only boost 7-8psi.

I would call the previous owner and ask if he had any problems with it or if he was able to change the settings. Like Sgtblue said, I'd list mods done and take some pics of the install setup so people can help you identify the problem.

 

i have the old style profec b and mine boosts 10psi if i have it on or off. shouldnt it boost 8 psi when off?

are they any flaws with the old style controller?(if thats the same controller the op has)

 

Assuming it is installed correctly and assuming you do not have boost creep issues, with the Profec B Spec 1 turned off and the dip switches correctly configured for a wastegate with an actuator, you should see 7-8psi with the profec OFF.

If you are seeing ~10PSI regardless.. it kind of sounds like you have the factory boost control solenoid still hooked up to the wastegate actuator. There are two nipples on the wastegate actuator, one connects to the primary turbo and the other connects to the factory boost control solenoid. You want to connect your stepper motor in between the turbo and wastegate actuator and you need to disconnect and cap off the other nipple on the actuator.

The first time I installed my Profec B spec 1 I left the second nipple connected to the stock boost control solenoid and experienced the same thing. You should also double check that the dip switches on the back of the control unit are set appropriately. The manual explains how they should be set. You can download the manual from Greddy's website.

 

Thanks for the responses. The car has been over-hauled by Pettit. Rebuilt motor, balanced twins, upgraded smic, ecu, etc. upgraded radiator, and a greddy profec b.

I moved the dials for high and low around and no difference. I will be tearing some parts out this weekend to get to all of the necessary things to look at and get back to this post with what I find.

 

anyone know how the pin setting on the back of the controller should be set up for the FD with stock twins? Thanks.

 

According to page 5 of the manual (http://www.greddy.com/img/PHP/products/pdf/687.pdf) you want to set up the dip switches as the "Actuator Type".

So set them up like this (the formatting is lost when I post to the board, pay attention to the numbers or see the pic in the manual):

up down up down
4 3 2 1

 

thanks man, my low setting works fine but the high setting seems to make no difference no matter what I dial it to so one of the guys mentioned maybe one of the switches may be in the wrong position.

 

how exactly is it hooked up? Take a picture and mark it up with MS paint

 

well, if the low setting is actually working fine, then the high setting should work too. These Profec Spec 1's are getting old though. I ended up having to replace my Profec with another boost controller because mine would short out after a while and then I would only boost to 7 - 8lbs... and then it would magically work again... which made for rather unpredictable driving. Maybe your high setting is bad?

but I agree with arghx, take a picture or at the very least descirbe your setup and we'll be able to provide more help.

 

thanks for all of the input, diving into this tomorrow afternoon. I will check my pin settings as well as the hose connections.

 

well, finally got some things removed to get a closer look. on the primary turbo, there is a small piece of tubing that comes off of the compressor housing that has two hoses attached to it. I noticed this piece has broken off of the compressor housing. Not good. I am going to try to use jb weld to reattach it.

any thoughts?

 

.

 

Is this what you are referring to?

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/help-identify-part-im-looking-852331/

If so, those two connections are for:

* oil injection nozzles
* oil crankcase ventilation

 

nope, it's a small line that has a hose connected to it that runs to what I believe is the profec b stepper motor, and another hose that runs from it over to the primary turbo's actuator

 

sorry, the other hose runs to the actuator of the second turbo, not the first

 

Yeah man, I know which line you are talking about. I have no idea what to do when that line breaks...

He is referring to the two nipples that come off the primary turbo that in a stock setup would run to the WasteGate Control Actuator and the PreControl Actuator.

Honestly, without those two lines I don't believe you will be able to control boost or transistion. I guess if you are unable to repair it you could figure out some way of blocking it off and then find another true unmolested boost source from the primary to run those lines from.... but this is way out of my pay grade. \

You are correct though, the Profec stepper motor should be attached from the primary turbo housing and then to the wastegate actuator. The other line between the primary turbo and the precontrol actuator should be left alone.

 

well, after further inspection, the line didn't break off of the primary turbo. It simply is inserted into a hole. Must have worked loose over time. I thought of simply sticking it back in, but decided to put a little jb weld on it so it doesn't wiggle loose again.

hopefully this cures my boost issues.

 

cool. Assuming you have everything else connected correctly you should be set. Without that line connected correctly it is clear why you where having boost issues. Good luck and let us know how it goes!