Problem, Symptom: Boost constantly builds while under load and under throttle. The boost builds very quickly and does not stabilize. I have to release the throttle to prevent disaster. The same behaivor can be seen regardless of the settings on the Profec. The Profec can be on or off, Balance can be mild or sharp, boost settings can be high or low with no effect.

Profec Installation: The Profec is installed using the Version 1 method. The big black Greddy motor is installed on the line from the primary turbo to the wastegate actuator. The other line on the wastegate acuator (going to the turbo control solenoid) is capped off.

The Car: 93 R1 with the following relevant Mods: PowerFC, Greddy Profec B spec 1, Pettit Intake, 99 Y-pipe & crossover, pettit underdrive pulley, RB catback (the main cat is still installed)

Other Notes:

1. I wouldn't describe the problem I am having as Creep, because my understanding with creep is that the boost will stabilize and then start "creeping" up in the higher RPMs. My boost basically never stops building.
2. I was always under the impression that if the Profec was installed correctly (which I think it is), and turned off, I should see no more than 7 to 8lbs of boost.
3. I bought the Profec used over a year ago, and have only recently got around to installing it. Could it be faulty? If so, I would still think that turning it off would leave me with 7-ish lbs of boost max.

I have tried to be pretty detailed but don't hesitate to ask questions if I have left something out. Any helpful comments would really be appreciated. Thank you for your time,

richard

 

temporarily remove the Profec from the plumbing by running a pressure source straight to the actuator. keep that other nipple capped. Does the boost stabilize?

 

Just finished trying that... the boost does hold steady at about .5 - .6 BAR... so 7lbs. This would indicate that the profec is bad correct?

 

Do you have it hooked up to the Normally Open (NO) port on the solenoid?

 

Older stepper motor... so I have an Out and an IN port. The hose from the turbo goes to the IN port... and the OUT port goes to the wastegate.

 

isn't there a dip switch on the back? is it set for internal wastegates?

 

The dip switch is set to Actuator Type... the other option is External Wastegate. I beleive it is set correctly as I bought the unit from another FD owner using it with a stock sequential setup. I know that doesn't mean much, but when I look at the Profec manual it appears to be in what I would believe to be in the correct position.

I guess prior to replacing the boost controller... I should play with those switches a bit huh? There is an over boost option for actuator type wastegates so perhaps I should try that. (duh).

I can't play with the car anymore for the night (mom's birthday) but I will try tomorrow and return with results.

Thank you so much for you help so far!

 

Okay, Monday Update

so I took a second look at the dip switches and they were definately not set correctly. Huge mistake on my part. Unfortunately, now with the Profec connected and the dip switches in the correct position, the car won't boost past 7lbs.

Taking the car back into the garage and connecting a mity pump directly to the Profec control Unit I beleive I have discovered the problem. With the engine off but the key set to On, I applied pressure to the control unit. I could hear the stepper. leaving pressure applied to the profec for about 5 seconds though, and the motor stopped. With presure applied I spun the *****... no response from the motor. Release pressure, turn everything off, turn it back on and apply pressure nothing. The power appears to be on in the control unit but there is no noise from the stepper motor. I lightly tap the control unit... and the noise returns only to stop again.

Long story short... something is wrong with the control unit. If I squeeze or tap the box gently it will power the motor.

At this point. I am pretty sure that the motor isn't getting power all of the time. When I had the dip switches set wrong, the motor would reset to the "normally closed" or external wastegate type which would cause me to almost always over boost. When I had the dip switches set correctly the motor would return to the normally open or actuator type which would cause the car not to boost past 7lbs. except on the rare ocassion when the control unit was working properly.

 

It just sounds like a connection inside is loose. Should be a decently easy fix if you know how to solder.