mr_jonboy

I know it seems that not too many of you have the AVc-r but I am having a problem that I am trying to diagnose and I believe that I have it narrowed down but am still making sure. The problem involves the mounting of the solenoid and pressure sensor. I have been noticing that when my car is cooler (engine warmed but hasn't been for long) the boost controller functions perfectly. I get full boost and everything is peachy. But I also notice when my car has been running for some time, it has been heatsoaked in traffic or has been idling that the boost controller seems to malfunction at high rpms. It will not hold the correct boost pressure and it has some very weird fluctuations at the higher rpms. It says in the manual about mounting both the pressure sensor and solenoid away from extreme heat. Well I have mine mounted up in the far front corner by the firewall on the passenger side. It doesn't seem to feel very hot in that area when the hood is up but I am assuming when the hood is closed that there isn't much airflow up there and it might get hot enough to malfunction it. Does anyone have any experience with this or know anything about this happening. I would like to hear some examples before I go ahead and move the pieces to some other area of the car, perhaps up by the intake. That can't be hot, can it?

rxrotary2_7

thats where i have mine mounted. side note...i dont have a stock hood. it is a mazdaspeed knockoff with a vent over the abs system so it cools that way.

here is a pic of my hood from their site.

that is my actual hood, they made it for me, but now offer it to the public.

what do you mean by "malfunction"? can you elaborate for us? what symptoms?

mr_jonboy

Well like I said I am only experiencing the problem when the car seems to be hotter. (e.g. after long idling, driving awhile, traffic, etc.). After I warm the engine up and just leave my house when the engine bay is still not too hot it seems to work perfect. I have tested this many times and it seems to be doing it everytime. I was talking to one guy that said he mounted his solenoid down by the intake and mounted the pressure sensor by the ABS unit and he said he has no problems. What the thing is doing when it is warmer is the boost falls off (only noticing in 1st and 2nd gear) and it also does this crazy fluctuation at higher rpm, say around 6000 and up. The fluctuation seems like the solenoid is opening and closeing really fast back and forth. When this happens my boost will just flutter. I get horrible vibrations b/c of it and my engine just vibrates like crazy b/c of the inconsistent boost. But right at the beginning of the drive when the car isn't as hot, the thing boosts perfect in all gears and all the way to redline.

Not sure how to explain the problem any better than that. I hope you understand what I am talking about.

neevosh

I have my sensor next to the ABS on the fender and the solenoid under the airbox. I've never had any problems. Did this problem occur only after you installed the AVC-R?

rx7speed811

maybe you have a faulty solenoid pack, or the wires are jacked.

maxcooper

I mounted my AVC-R sensor by the stock sensor on a piece of aluminum bar stock that I bent, cut and clamped under the stock MAP sensor bracket and then under the bolt of another bracket on the firewall toward the fender. Dave from fc3s.org gave me a tip that the sensor will malfunction if you put it somewhere hot, so putting it on the driver's side (U.S.) seemed like a good idea.

It seems like the solenoid would be better in a cool spot also, so I mounted it to the frame rail in the "cool air intake" area. However, that probably wouldn't work with an air box. If I had an air box, I think I'd still try to mount it up near the air box to keep it away from the heat of the turbos as much as I could. It is wise to keep the hoses short, but a cool environment seems equally important. I will have hardlines to the wastegate (single turbo) to reduce the "flex" in the signal path.

I suspect that your sensor or even the valve may be malfunctioning from heat. Have you compared the boost reading from the AVC-R against a boost gauge (or ECU reading) to look for any discrepancy during the malfunction?

-Max

mr_jonboy

It works. It's alive. That was the problem boys. I moved the solenoid to a ledge that is where the stock airbox mounts to. I have the Pettit intake so there was plenty of room there. I mounted it pretty much as far forward as I could so it is now seeing has cold of air that the intake it so hopefully that is cool enough. I left the pressure sensor where I had it which was up in the corner by the ABS unit. I put everything back together and took it for a spin yesterday and it ran perfect. I was getting some big spikes but that is just going to have to take some time to properly tune my AVC-r. But I drvoe it for awhile to get the underhood as hot as possible. In traffic, stop and go, etc. and it never once did the problem that it was doing. I believe it is cured. Until the next problem happens. So take it from me, the hotter the solenoid is the less acurate and messed up it will become. So mount it in a good and cool spot. Thanks for all the info, dudes.

widebody2

guess I should move mine that...

mr_jonboy

Where do u have it currently?

RexTech

My car has a Profec-B boost controller, I don´t know if the solenoid box looks like the Profec´s, but if this help, I mounted mine over the 4 fan relays, you know at the passenger side. I fix it there with tie raps. In that way my solenoid box is very near to the turbos, it is not in a too hot place and works great.

mr_jonboy

I had mine there but had to move it when I bought the Apexi BOV b/c that is where it mounts.

level7

iTrader: (3)

mr_jonboy:
good to hear your avc-r is working good. heres where i mounted mine:

solenoid


preasure sensor


everything was working great. i was tuning the avc-r on 9psi to be safe. the first 2 runs went fine, held boost perfectly through the whole rpm band. on the third run at about 5700 rpms i heard a noise like something poped off.

now when the secondary turbo comes online i hear boost preasure escaping and only getting about 3psi on the same avc-r setting i ran before. the preasure release sounds like its coming from the drivers side. the primary holds boost perfectly until it transfers over.

i checked:
intercooler piping
vacuum lines
turned avc-r off
all lines connected to avc-r

everything seems tip top to the eye. anybody got any ideas? turbos are stock and only about 3 months old from brand new. any feedback would be appreciated.

chris

rynberg

Level7, check this website out:

http://home.istar.ca/~dvandit/TurboT...shooting.shtml

hope it helps.

mr_jonboy

Chris,

That is exactly where I have mine mounted now. I did have the solenoid up by the pressure sensor but that is where I was getting the problems. I thinnk b/c up there in that little corner there is no air flow what so ever to keep the solenoid cool. Moving it under my intake like you is cooling it off much better I believe. Well it must be b/c it is working.

I am not for sure where that leak would be coming from but I have some people talk about the pressure sensor hose on the driver side right up on the firewall. Maybe since you heard the noise real well and it sounded like the driver side, maybe it could be that but that probably wouldn't allow you to get pressure in the first turbo. I would just read up as much as I could on turbo troubleshooting and see if any problems sound similar to yours. Troubleshooting the turbo system is a PITA.

Good Luck, let us know how it comes out