I have had my car running great for about 2 mos now, my 1 issue was I needed a boost controller so I bought a Greddy Profec B and had it installed early in Nov. Since it's been great, I could drive it however I wanted while never going above 12 lbs of boost. I was very happy...

well 3 days ago it was very cold and I was driving to work, a new RX8 pulled along side me on the I-10 and wanted to see what I had so we each jumped on it and I noticed my boost going to 15-16 lbs. I got off the gas and turned the Boost controler all the way down. I gave it a test and it held around 10 lbs of boost, I was happy enough with this as I did not want to over boost my new engine.

The RX8 and myself gave it another go and at 10 lbs I left him very quickly, I slowed down and he asked me to pull over to see my car, I did and we talked for a few, nice guy.

The next day I was headed to work and it was just as cold, I went to pass a car on a 2-lane rd and WOT in 3rd gear, I quickly saw the Boost gauge go up to almost 18 lbs. I almost ****. I checked the Boost Controller and it was still turned all the way down. I thought it could just be the cold but hell isn't that what the boost controller is for, after all it's called a "BOOST CONTROLLER".

I was on the way to work today and the temp has gone up at least 15 deg and is in the upper 40's or lower 50's, I thought that this might get me in check again but no, even in lower gears, on primary turbo the car wants to make 16-20 lbs of boost when you just give it anything past half-throttle.

So needless to say I am babying the throttle to save my engine....

Please help, just FYI I have Defi Boost Gauge and don't think it's inaccurate.

P.S. Worst part is I have a famous passenger I need to give a ride in my FD tomorrow and It would break my heart for it not to be running good. (I work for GE Plastics and we are a asscociate sponsor for the NASCAR DeWalt Ford #17 and Matt Kenseth is coming in town tomorrow to do a autograph meet and greet at my site and I was chosen to pick him up from the airport, cool enough a NASCAR Champ riding shotgun in my FD! However I'll be sad if I can't give him a quick show of what our FD's can do...

Please help if you can!

 

Since you are seeing very high boost in both primary and secondary, it shouldn't be boost creep, I am guessing that your boost gauge is screwing up.

Get it calibrated before you panic. However, as you are doing, be gentle until you know that the problem is for sure the gauge.

Another possibility, if the boost reading is accurate, is that the line from the intake manifold to the controller has come loose.

 

Check that the lines from the primary turbo compressor housing to the boost controller, and from the boost controller to the actuators, are intact. Also check the lines leading from the actuators to the top of the engine block. If any of them popped loose, the actuators will not hold pressure, and the wastegate will not operate.

No wastegate = no boost control.

Dave

 

I have checked the line from the UIM to the guage and it's in place

I also checked the 2 lines from the boost controller to the turbos and they are in place.

I'll check the others asap.

Thanks for your suggestions

I also had someone tell me the solenoid in the boost controller could have failed.

Is this common?

 

also check to see that the cap on the wastegate didn't pop off. you did cap it didn't you?

 

Something aint right. Stop boosting the car untill you find the problem, before you blow the motor. I doubt the defi gauge is that much off, but it is possible. What are your mods? And yes you can boost creep on the first turbo. Go in 5th gear at like 50 and floor it and lug the motor and see what happens...

 

Mods are:

Stage 2 Rotor sports racing motor
ACT Clutch
Apexi intake
Bonez DP and Hi-Flo Cat
Racing Beat Dual Tip
Greddy SMIC
Power FC
Fluidyne Rad
Greddy Profec B

 

What are the boost settings on your pfc? Did you disable the factory wastegate control solnoid when you installed the profec?

 

originally .8 and primary set at 72% and secondary set at 50% but yes we disabled the factory control sol when we installed profec B.

So the seetings are null and void now, correct?

All the lines that I can see without taking anything apart are ok. The lines going from the profec B sol, the gauge into the UIM etc. also the wastegate was capped and still is.

I am hoping is simple like a line came off, am at work and will investigate further when I get off in the am.

P.S. Right before I came to work an 8 yr old girl riding her bike slammed into my Fd (she's ok btw) which I happened to have it parked on the street because I was cleaning the garage and driveway.... two fist size chunks of paint out my rear bumper. Ouch, I had the car painted 6 weeks ago.... : ( bad week.

 

I took the intakes off this am and found all lines to be intact and connected...

So I am assuming the solenoid is bad? I bought used on forums and I talked with the seller and he had used for 1 1/2 years prior to me getting it.

Is this common?

Also thinking of going to a manual boost controller after reading some of Damian's posts...

What do you guys think?

would it be any more difficult since greddy profec B is already installed or should I just buy a new solenoid or newer greddy profec B 2?

Opinions appreciated.

 

I ran into a similar problem years ago. Bought a manual BC and it fixed everything.

 

If you have 100% verified that everything is ok with the installation and that the wastegate door is still mechanically connected to the actuator arm, then it is entirely possible that you have a bad Greddy solenoid.

 

Do they come off often?

I didn't go that far in dismantling today... correct me if I am wrong but do I have to take off DP to check that?

 

https://www.rx7club.com/showthread.p...29#post4502283

As you can see, the downpipe is close but not obstructing the wastegate actuator arm. You will need to remove some heat shields though.

Dave

 

port your wastegate if this doesnt solve the problem the fact that its colder out this could be the problem

 

BAD ADVICE! He doesn't have boost creep, per se. His wastegate isn't operating, period.

 

Found the problem! The hose that went to the wastegate actuator was split on the backside... replaced and wa-la!

Thanks for all the help!