I just finished my two month project of rebuilding my RX-7 that I bought in March non-running. We rebuilt the motor, street ported it, rebuilt both turbos, did the vacuum hoses, and some miscellaneous stuff (clutch, waterpump, spark plugs, etc.).

Anyways, almost everything is working properly. The odometer doesn't work for some reason even though the tachometer works. The low coolant light stays on all the time (I did the linear temp gauge but didn't jumper the back of the gauge), is that a problem?

And finally, the biggest problem for me...I don't think the secondary turbos are boosting. I did throw out both pills...I'm waiting for my boost gauge and two manual boost controllers to get here. Could this problem be because the primary turbo is not creating 8 psi or higher? I hear a loud woosh at ~4500 rpm and no boost.

Any advice? I just waited 2 months to get this thing running and I'm so anxious to get this thing running properly. Please help, thanks!

 

Yes, in order for the secondary turbo to even work, the primary must see 8 psi. With both pills out, its not going to work properly. However, that loud woosh worries me. Does your boost go 10 till 4500 rpms then hit 0? if so , it could be somthing else.

Id say throw those pills in, see what uget, and work from there if theres still a problem

 

I don't have the pills...I didn't know about them until after I did the vacuum hose job. I checked the nipples on the turbo housing but there's no restrictor in them either so I'm pretty sure I threw them out.

Yeah, it's a really loud woosh...but no wooshing under 4500 rpm. Actually no wooshing in first gear, but when I shift to second and it's around 4-5000 rpm just continuous wooshing.

 

and 0 psi?

 

Dunno about psi until tomorrow when I install the boost gauge.

Another question, since I'm going to replace the pills with two manual boost controllers. What sequence should I follow when installing them?

Should I install the wastegate one first, adjust it to 10 psi. Then install the pre-control one and hopefully dial out the spike? I know to start wide open with the wastegate controller. How should I start with the pre-control one? Some other people said to just have it barely cracked open.

 

This will help with the manual boost control:

http://www.rx7turboturbo.com/robrobi...controller.htm

...and about the linearized temp gauge: if you didn't solder the jumper to the back of the gauge then it isn't linear.

Good luck

 

The coolant buzzer circuit is simply one wire, but it goes from the sensor on the front of the T-stat housing, then there's the connector & the wire joins the MOP portion of the main harness. Then it pops out by the oil filler neck, & there is another connector (black with yellow innards) on the main starter/battery harness. This is the one that is easily overlooked as the connector is on the back side of the harness & is very short. You're better off looking for it with your fingers then wtih your eyes...

Low secondary boost could be caused by the lack of pills. If you place a restriction in the PC line & still have 0 on the #2 turbo check the 1-3/4" hose that runs from the rear of the Y-pipe up to the rear turbos brown blow off valve (this is the Charge Relief Valve I think). If that hose is split then it'll vent the majority of the rear turbos pressure to the engine bay.

 

Okay, just started up the car this morning and I know the temp gauge is not working properly. It just goes right up to where I calibrated it with the potentiometer. That means I have to complete the mod by jumping the back of the gauge itself.

As for the boost problem, I will install the boost gauge today and record my boost pattern. Then I'll install the manual boost controllers this weekend to see if it solves the problem. But what's the wooshing sound at 4500 rpm? Besides the pills, is there a leak? Or would the sound also be affected by the lack of restriction in the pre-control hose?

And as for the coolant buzzer. Your suggesting I check for a connector on the battery harness? I'll take a look in a little bit and let you know.

Thanks everyone for their suggestions. And thanks ES for your support as usual. Wish you were in So Cal.

 

"But what's the wooshing sound at 4500 rpm? Besides the pills, is there a leak? Or would the sound also be affected by the lack of restriction in the pre-control hose?"

You're description of the whoosh at 4500 is the reason why I suggested a possible split hose to the Charge Relief Valve. That valve shuts at ~4K RPM. If it's open (meaning you routed the small vac hose to the wrong solenoid) or if the larger hose is split you will get the whooshing noise & very low if any at all boost from 4500 up as all of the #2 turbos boost is being dumped to the engine bay.

"Or would the sound also be affected by the lack of restriction in the pre-control hose?"

Doubtful.

"And as for the coolant buzzer. Your suggesting I check for a connector on the battery harness?"

Yes. if you look at the FSM you'll see two connectors on that wire as it makes it's way up to the dash circuit. It joins the MOP & CAS portion of the main engine harness, then pops out & joins the battery/starter & dash harness. The location of the connector on that battery/starter harness makes it VERY easy to overlook upon re-installation of the engine.

"And thanks ES for your support as usual. Wish you were in So Cal."

Your welcome. Good luck getting the little things ironed out. I know how long those little things can stick around & bug you from personal experience. I'd offer to come by & help, but that's one hellava long tripl

 

Low coolant light/buzzer and odometer now working. One wire as ES said. Oops!

Odometer is very dim, not even red, like a white color. Really really dim but it's working. Anyone see similar problem?

No boost gauge today...tomorrow probably. I'll let you guys know my boost pattern then.

 

Got the boost gauge installed. In 3rd from 35 mph I go WOT and boost goes up to 7 psi then at 4500 rpm it starts decreasing along with the wooshing sound.

 

Found the boost leak. My secondary turbo outlet to the Y-Pipe was not tightened down so the gasket was the wizzing noise.

Now I have the turbos working but I have major boost creep. My pattern was 10, spike to 11, down to like 6, and immediately back to 10...then close to redline it went like 11-12-13-14 and I let off the gas immediately.

I also installed my downpipe yesterday when I found the leak. I only used 3 studs because one broke. It makes funny noises.

I am using manual boost controllers to control the boost. They are ball/spring type. Maybe that's causing the boost creep? I just need to buy my AVC-R.

My idle is pretty high too, 1200 rpm. I'll try the ISC.