Profec B solenoid replacement

[Heat]

Hi all,

Having some issue with my profec B after I replaced the solenoid.

Story:

1st generation profec B (not spec II). Used for 8+ years, worked perfectly. A few months back, it started to not hold boost. I'd get just wastegate spring pressure. On occasion, it would work correctly and I'd hit 20psi, but most of the time just wastegate pressure. Did some research, figured it was the solenoid, so I bought a new one:

15900535 Part # from alamo. Their website says "This is a replacement to the original Profec B Solenoid Valve".

The old solenoid is the "black box" with only 2 ports, IN and OUT.

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The new one I got is the type used with the Spec II, with COM, NC and NO ports.

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Harness is the same.

Hooked up the new one, boost source into NC, COM goes out to wastegate (tial 40mm). NO port has nothing plugged into it.

Now, there is no boost control. Wastegate never opens so boost climbs until I let off the throttle. Even with the Profec B turned off. Obviously, all the air going in through NC is being bled off from the NO port, even with the unit turned off. This doesn't make sense? When it's turned off, shouldn't it just act as if it's a straight pipe?

For the record I tried plugging the NO port (air has nowhere to bleed off then) and it hits wastegate pressure like it should.

Has anyone replaced the solenoid from a 1st gen profec b with something other than another 1st gen solenoid? Scoured the net for answers to that with little information either way.

Any help would be appreciated.

 

[turboglenn]

open th4e old profect solenoid box (3 allen screws) and you'll see there's 2 small solenoids inside, which each one also has a port that is left open.. blow through them in the way you would route the hoses and do the same on the new one and you can figure it out... I've replaced the old ones with pneumatic air vlaves called "310 valves" and used that same process to figure it out, but don't ask me to remember that off the top of my head

 

[mheidemanjr]

Well if u can figure it out I got a prefec box with all the wireing ill sell you for a great price

 

[Heat]

open th4e old profect solenoid box (3 allen screws) and you'll see there's 2 small solenoids inside, which each one also has a port that is left open..

Yeah I did that. I can tell which is the primary solenoid and which is the high boost one by how they are wired. Everything looks fine, but it's just a visual inspection. Air travels freely through IN -> OUT. Nothing comes out of the small solenoid ports inside (wouldn't expect it to).

blow through them in the way you would route the hoses and do the same on the new one and you can figure it out...

Can you elaborate a little on this? I'm not sure what you mean. I think what you're saying is that the two solenoid valves inside the box are essentially the "NO" port on the new style solenoid. What does that have to do with hoses? I'm sure the hoses are hooked up the same way on the new solenoid, that's not what my question was about.

I think it has more to do with the circuitry being different, things like resistance, voltage etc that doesn't match up from the old solenoid to the new one.

 

[Heat]

Since I've found numerous similar threads on the net with no conclusion as to whether or not this solenoid replacement is compatibile, I'm hoping to help out anyone who finds this thread in the future with the same problem.

My conclusion is that the solenoid from the spec II DOES NOT work with the original profec b.

Tried a bunch of different things, can't get it to work. Found no conclusive evidence on the web that it works, or at least doesn't plug and play.

Emailed Greddy asking for an answer, no reply.

The boost controller has performed well for me, but due to lack of a straight forward solenoid replacement, I'd recommend not getting an original profec b.

 

[turboglenn]

the twe inside are not a low and high boost set of solenoids,,they operarte together at all times to allow a large enough anmount of air to be bled off.. i don't want to sounds short about it, but you have to be able to look at the system as a whole and see how it's working and just duplicate it with the one large solenoid instead of two.. blow throufgh the holes..the one that's open and free on the old one.. make sure to hook the new open and fre one to the same place..just picture the old box as if it only had one small solenoid, ignore the other and it's plain as day to see.

EDIT: okay i'll do the work for you... the port left OPEN (or where the air is clead to atmosphere or back into pre-turbo piping)on the new solenoid.. is the same as the 2 ports from the top of the small solenoids inside the box..easy enough..i did that from loking at pics of both setups which you can download both PDF's at greddy.com

 

[Heat]

I think what you're saying is that the two solenoid valves inside the box are essentially the "NO" port on the new style solenoid.

IN == NC
OUT == COM
interior solenoids on the black box == NO

If you read what I said earlier, I tested everything, even plugging up the NO port to make sure the air traveled through the solenoid.

Which ports are for what isn't exactly what I'm asking here. I THINK the signals/resistances of the two different profec b styles are not directly compatible without some circuitry manipulation, which is why I can't get it to work. Also, there are a ton of threads like this floating around:

Greddy Profec B-spec 1 solenoid replacement - NASIOC

with no conclusion as to whether or not it works. I was just wondering if anyone has used this since the harness is the same and it's sold as an "original replacement" at a few places I checked. Then the additional baffling part of it not letting air through even when it was turned off (I'd have to attribute that to the valve locking in the closed position when I power off the control unit).

Either way, appreciate the help.

 

[turboglenn]

hmm. i'm using an industrial valve (just 1) in place of the two iside the box.. it works fine.. but i'v ealso taken old mitsu solenoids and put them in the greedy box, i can try it out anytime and i'm sure it would work...the solenoids only take the same juice to fire as a relay does, lesss than one amp.. it shouldn't know the difference between one or 2 to be honest

 

[Heat]

That's interesting. I had read some other threads that mentioned things like that too but didn't pay a lot of attention as to whether it was about the spec I or spec II.

The spec I uses a stepper motor in conjunction with the solenoids and the spec II is just a solenoid. Originally I had thought because of this the signal would vary but I guess the solenoids are the important part here and those are either open or closed so I guess it should work.

 

[turboglenn]

I've had many shorts show up in the green and white wires on the greddy box, it may be you have it correctly and that one of the wires is bad.. one should show a 12v signal IIRC and the other shoudl be continuity to ground when the box is on

one way i've found to test the wires is hook up a mitsubishi fuel pressure or boost solenoid to the output wires of the greddy..the hook a small hand pump ( i use the one like you strap to a 10 speeds frame for filing tires) and I have a fitting from a 1g manifold fuel vac line (one to regulator from mani) stuck in it like a schrader vlve and use that to put pressure to the boost controller..when you pump a little pressure into it you should hear your solenoids click.. I ddin't mean to come off dickish in my earlier posts, and i have sen how frustrating this can be when there's a bad wire.. but the main control box can be shorted to ground and tossing sparks and the signal isn't powerfull enough to fry the box at all (i've done all the above) you realy can't hurt the controller with bad wiring at the solenoid or even dead shorting them to test for spark (if it's a sparkin it's a workin i have come to conclude)

let me know and keep the progress coming, I have the profect B with 3 knobs and 4 dipswitches on the back to set internal or external gate, and it has power/ground in, vac/boost in, and 2 wires to solenoid out (if that helps at all )

 

[dkalfop]

HELP! I hope someone can see this, I'm really having a hard time trying to replace my new universal spec 2 solenoid with only in and out vacuum ports. This new solenoid has three ports, COM, no, on. Do I leave the third open to atmosphere or cap it? It was covered and started making that clipping sound only after a week driving around the neighbourhood and kind of worked, anyways. My question is when I connect to COM and NO to there it's perspective hoses, what do I do with the third port for ON? It was capped I'm going to check it free to atmosphere? Help please my car is running amazing after 12 years of rebuild and want the boost at 20 psi on a 20g rocks!