I am new to the fourms. I have a 1988 Turbo II. the jackass that owned it before was pushing 14psi on a 38,000 mile rebuild. Im trying to set it back but am having some problems with the way he rigged the vacumm lines. Anyone have a diagram or a pic of their engine bay showing the lines? thanks.

 

Try the FSM, im sure it shows a nice diagram in it!

btw, the vacuum hose from the wastegate goes directly to the nipple on the turbo outlet. Thats the only thing that controls the turbo boost. If you got a larger exhaust, open air filter etc you might see 14psi anyway since the s4 wastegate is to small. You need to port the wastegate to prevent boost spikes!

Sindre

 

whats FSM?

 

Factory Service Manual

You can find it, along with lots of other info n the 2nd gen FAQs

 

Factory Service Manual

Here it is...
http://www.wankel.net/~krwright/cars/rx7/88_manual.htm

 

Yeah the FSM tells you everything you need to fix 98% of the stock **** on your 2. gen

 

why are you so quick to call the guy a jackass when you don't know what an FSM is or how to route vacuum lines?

 

you're right, i shouldn't be quick to call him a jackass. His acctual charcter was a jackass. Sorry i don't know too many abreviations or how to route vacuum lines... hope you all on the fourm can still accept and help me.

 

a turbo diagram or vacuum line diagram doesn't seem to be there. am i missing something.

 

You want the Fuel and Emissions--turbo section.

 

The vacuum lines won't cause the boost pressure to be high.

On a series four there is only one vacuum line to the turbo assy. It goes to the twin scroll actuator on the turbo unit. If the vacuum was on that one line 100 percent of the time, THEN the boost pressure would be lower than normal.

IF the vacuum was missing from that line, then the boost would be NORMAL, no more, no less. It would be a touch slower to spool up, but the max boost would be the same as if the vacuum was there and being operated from the twin scroll solenoid in a normal way.

Just find the twin scroll solenoid and it's two vacuum hose. Remove the vacuum line off the twin scroll and blow from one end to the other to confirm the line is indeed routed from the twin scroll to the twin scroll actuator.

 

There is NO definitive picture of the lines themselves showing them going from point to point.

Common sense and some work is required to figure out where they go from end to end.

You need to know what each item does in life to begin.

Like the Relief Solenoid. Has a Blue plug on it. It controls part of the ACV. Find the ACV. From reading you know that the Relief solenoid has two lines going to it from the ACV.

So you remove the lines from the solneoid. You blow thru one line at a time and make sure the lines are going to the ACV. One line is PRESSURE coming out of a nipple on the ACV going TO the solenoid. The other line is leaving the ACV going to the ACV. It is just sending the pressure that arrived at the ACV back to the ACV to control the diaphram at the bottom of the ACV.

Same with the other solenoids.

Anyway, high boost isn't a function of a vacuum line.

 

what is high boost a function of?

 

http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm

They give a description of how the FCD works with the boost sensor.

I might have mispoke just a bit. The line that goes to the boost sensor is both a vacuum and a pressure line. Oh well. Other than that line I don't see any vacuum line causing a boost problem. Maybe I need to work on that a bit and figure out a scenario where a vacuum line effects boost.

Like the article says, the output voltage to the ECU from the boost sensor determines when you hit fuel cut on the back rotor.