Factory Boost Solenoid Info

[slayer]

Does anyone know if the factory boost solenoid on the R33(GTST) is only that, or does is also serve a role as the MAP sensor?

The reason for asking is I fitted a bleed valve (yes I know its a bit dodgey, but I have an EBC coming next week) and was told to disconnect the vacuum lines connected to the factory solenoid and patch in the bleed valve direct with a fresh piece of hose from the manifold pickup to the wastegate.

The problem is apart from the added boost the car feels more 'doughy' now and I am guessing its running way too rich plus fuel economy has got even worse (like 350-400 out of a tank when driven conservatively).

The bleeder seems to work fine (8 PSI dialled in), but I am concerned that:

- as the boost solenoid is now still connected electrically but only has a piece of hose looped back between its vacuum connectors (to keep it clean) it is probably working its tail off trying to drop boost and will burn out (I plan to use it later when I fit a Wolf3dV4 with built in boost control)

- the solenoid also works as a map sensor, and is screwing up my fuel mixtures.

Does anyone know? Should I disconnect the solenoid wiring, or bypass it or something?? Or does the solenoid have nothing to do with it, and its just the boost increase upsetting things? At the moment I have stock everything except airpod.

Any advice appreciated!

Conrad

[rev210]

mate you probably have left one of those hoses you unplugged from the solenoid 'open'. You need to have one of the hoses plugged with a screw. There should be only one line (in the middle the bleeder) between the intake pipe and actuator. The other hose you block off with a screw. It sounds like there is a vacume leak.

[slayer]

Thanks Rev, but checked that first - all lines are plugged

You riun a bleeder, did you disconnect the solenoid (unplug the wiring harness) when you fitted it? I am assuming its my air fuel mixtures have screwed up as throttle response is shite, but I have also heard the Throttle position sensor can get out of wack and cause the car to constantly overfuel...

Im hoping someone can confirm or deny about the MAP sensor...

Conrad

[Jay95R33]

slayer,

The boost solinoid is just that. It doesn't have any feedback capability. I've had a look at the wiring in the ECU (on a circuit layout) and it's just a switched output.

As rev said, you may have a leak.

I basically got rid of all the factory rubber pipes to the wastgate and ran my own. There is one of the factory pipes that needs to be blocked and that's the one that feeds back into the intake. The one that goes down and under and disappears

I found throttle/boost responce was better, but then again I've got an anti wastgate creep valve on mine which would help heaps.

Cheers

J

[slayer]

Thanks for the info Jay95R33, perhaps I just have a tuning problem. I will check around for leaks again, but I did remove all the OEM piping and replace it, and then blocked off the return line as you suggested so I think its all airtight.

So you have left your solenoid plugged in (electrically)?

I will probably be chucking a HKS Hi-Power exhaust with a custom dump pipe (seperated wastegate and ceramic coated) in the next week or so and when the guys fit it I will get them to check it out.

I have heard that some of the R33's have quite retarted timing, and also the throttle position sensor can be out of wack and cause problems too so I will get it checked over..

hmm, this car feels VERY slow compared to my old WRX (180AwKw) ... need to get its power output up, but money is always a problem

PS - that reminds me, I will pick up an airbag this week for your cupholders, I promise

[DAMQIK GTS-T]

The standard ecu requires that the standard boost solenoid be left pluged (electricly) in or the ecu will go into limp home mode (over rich) defult timing and fuel maps.

I would suggest that you reset the ecu and re test drive the car let us know if you still have any problems. (note the ecu will need a reset to get out of Limp home Mode.

Damqik

[slayer]

Thanks for the info Damqik, I never actually disconnected the solenoid but I have tried an ECU reset twice (I fitted an Apexi airpod at the same time and wanted to make sure the maps took into account the airflow difference).

Ta

Conrad

[Jay95R33]

No problems slayer - there's no rush.

Sorry, I forgot to say that I've disconnected the factory solinoid and it's sitting right here next to me in the study

I heard from a few places that if you unplug it it'll stuff around with the ECU, so I unplugged it and ran the diag's on the ECU and still got the 55 code (everything OK).

I'd suggest that you try unplugging it and run the diag's just to make sure, and keep an eye on how the car runs. If it's disconnected now, re-connect it and see if that helps the feel of the car.

J

[slayer]

Interesting - I might try disconnecting mine (I would prefer to do that anyways, I worry it is destroying itself and I will need it for the Wolf3dV4 fitment) and see how I go..

ok next silly question - got a URL to the ECU diags?

Ta

Conrad

[Jay95R33]

Ummm, try on Meggala's site. Heaps of good stuff there.

http://www.meggala.com/main.htm

[DAMQIK GTS-T]

The solinoid wont show up as a fault code because there isnt a code for it.

Damqik

[Zahos]

Originally posted by DAMQIK GTS-T

The standard ecu requires that the standard boost solenoid be left pluged (electricly) in or the ecu will go into limp home mode (over rich) defult timing and fuel maps.

I would suggest that you reset the ecu and re test drive the car let us know if you still have any problems. (note the ecu will need a reset to get out of Limp home Mode.

Damqik

I dont think this is correct.

I have had mine off for about 9 months now, maybe more. I had left it connected electronically in fear of this, but decided to try it out, and it made absolutely no difference. As Jay95R33 said, there is no feedback, so the ECU wont even know it is unplugged....

Zahos

[DennisRB30]

This is just the thread I was after. I just finished typing a new thread about it but I found this thread before I submitted it.

Anyways, I assume the solenoid you speak of it the one that connects to the wastegate actuator hose via a T piece, and has another hose that connects to the intake prior to the turbo.

To summarise, is this correct procedure to install a bleed valve? Disconnect the solenoid hoses and plug the one up that connects back up to the intake prior to the turbo. The bleed valve can then be installed where the T piece for the solenoid was. A restrictor should then be placed in the line for correct operation of the bleed valve.

Sound right? Also, is the restrictor best placed on the wastegate side or cooler pipe side of the bleed valve?

Cheers

[slayer]

Hi DennisRB30, I am running a straight pipece of vacuum line from the manifold pickup that the factory boost solenoid was patched in to as you suggested, to the solenoid and then onto the wastegate with no restrictor and my boost doest spike and just bleeds off progressively at the top end (probably acceleraterated by the backpressure in my stock exhaust).

I think they recommend against a restrictor as well as you lost adjustment resolution on the bleed valve. I think the restrictor is primarily set up for the factory solenoid only.

[kidd]

what about getting someone else to do it. r u all mechanics or something!!!!

[DennisRB30]

Originally posted by kidd

what about getting someone else to do it. r u all mechanics or something!!!!

Na, just tight arses

What does the sonenoid do anyway? Can't it be left on, or would the system not work with a bleed valve?

[Zahos]

The solenoid is setup to work in the same way as a bleed valve, but under controlled conditions. The ECU decides when and how much to bleed off. You could put a flow control valve in place of the factory solenoid and it will work as a bleeder would. You wouls also pay less than half the price of a bleed valve.

[DennisRB30]

OK. What is a flow control valve and how does it opperate?

[Zahos]

it's like a tap. You adjust how much air/fluid flows through it. So if you put one in place of the solenoid (which is like an electronically controlled flow control valve), you basically have a bleeder setup.

[skyzerr33]

out of interest for slayer if u haven't found the map sensor yet its the little black box on the drivers side of the enginebay near the firewall. IT has a vacuum hose that leads to the boost solenoid.