aznraver

Here's a tuff one for you guys.
I've talked with a lot of specialist and nothing good came out of this.

My car is a 93 rx7 with 95,000km.

I've been having a really really really weird boost problem and it goes like this.

When I am on first gear, I get good boost patterns all the way.
However when I shift after 6000rpm to second gear I can 0 psi!!!!
on second gear the rpm will go up to the end but at 0psi!
When I let go of the gas I hear a weird high picth whistling sound....
Press on the gas again on second gear and still get 0 psi...
But then When I shift on the third gear , Full boost again but very fierced...

It does this on any gear...for example if I start shifting first and second gear at low rpm and then on third gear at high rpm, it does the same on third gear...

I get no boost problem when i shift at low rpm...it's like there's something that's staying open but it can't be since it comes back to normal only when I change gears....

So it is as if the rpm has to drop really low so the "something" closes....

I need your expertise, thank you guys.

aznraver

Another question i Have is how rich is a rx7 suppose to run because sometimes my a/f is at really rich...

Rated R1

This is an easy one. Replace the turbo control solenoid that sits on top of your air control valve.

aznraver

Are you sure . why is that? pressure side Turbo Control solenoid ? Got any pictures on where it would be located? I am too lazy to search
thanx

aznraver

I am trying to find it out from mitchelle 's manual....which one is it?
Charge control solenoid???

Mahjik

iTrader: (1)

Rated R1 is da man!


aznraver,

Check this site:
http://www.autosportracetech.com/RX-...leshooting.htm

"The Turbo Control Solenoid / Actuator is one of the more complicated actuators as it requires both vacuum and pressure to operate properly. This actuator is controlled by two solenoids, (both are wired together to the one ECU output) one solenoid applies pressure to one side of the actuator and the other applies vacuum to the other side of the actuator. With pressure on one side and a vacuum on the other side of the actuator, the speed of the actuator is improved. A typical problem is loss of Secondary boost in 1st or 2nd gear at 4,500 RPM, but reliable operation in other gears. This points to one side of the Turbo Control Actuator not getting it's pressure/vacuum, so it will still operate but not quickly enough."

If you look at the vacuum diagram:
http://www.scuderiaciriani.com/rx7/v...e_diagram2.jpg

You'll see there are 2 solenoids for the turbo control. One on the solenoid rack, the other is mounted to te ACV.

aznraver

I'll try that out thankx guyS just another one...how much for the solenoid usually?

dgeesaman

iTrader: (7)

$50 US is about Malloy's price. Local dealer price may be higher.

On the diagram, it's the solenoid in the upperleft without a letter label.

Although with the pressure out, and just vacuum pulling on the TCA, I would expect you might still get a little boost. Your mechanic should test the CRV and CR Solenoid as well.

Dave

aznraver

your mechanic lol no i'm doing this myself and the mazda dealers here in montreal are idiots...they don't know what i'm talking about...any web site where i can order the parts and parts numbers please?

dgeesaman

iTrader: (7)

Malloy is the place to buy from. To just get a quick price, I like the mazdapartscheap.com site. You'll find Malloy's contact info in the newbie FAQ thread.

Next, use your boost gauge and tee into the lines between the Turbo control pressure, turbo control vacuum, and charge relief solenoids and their respective actuators. I think I got 1/8" tees and extra rubber hose at the auto parts store. You can do it by just unbolting the pressure chamber and moving it out of the way. Make sure they're producing pressure/vacuum at 4500rpm. The turbo troubleshooting page on www.scuderiaciriani.com as well as the one on autosportracetech.

If you haven't yet done the vacuum hose job, you should probably consider it soon.

Dave

aznraver

thanks alot...
are theses parts correct?


18-7410-N390.....SOLENOID TURBO CONTR..93-95 ON RACK..........$ 74.31
18-7410-N3A1.....SOLENOID TURBO CONTR..93-95 ON ACV...........$ 74.31

dgeesaman

iTrader: (7)

Not quite. Those look like Mazdatrix's numbers, which are rearranged versions of the actual Mazda P/N.

The correct Mazda numbers are N390-18-741 and N3A1-18-741.

Dave

aznraver

thanx got that... 60 us for each...WOW EHEHEH

aznraver

guys guys guys... I just found out that I have a check valve going in the air tank near the manifold cracked...is it me or i can forget the problem about solenoid and i should think it's the check valve....it's cracked!!!! where can i find one?

maxcooper

Here's a cheaper-than-stock alternative that should be durable:
https://www.rx7club.com/showthread.p...on+check+valve

I tried some cheap auto parts store ones once and they only lasted 10K miles or so.

Try replacing the check valve before buying anything else.

-Max

TEDDER1

iTrader: (1)

BEFORE YOU ORDER ONE!

Mine had the little C-clip come off. So the actuator didnt move the arm.

CHECK IT FIRST!

TEDDER1

iTrader: (1)

My local parts store had em...

dgeesaman

iTrader: (7)

Yeah, pretty much any check valve that has similar sized barbs will work for now. The viton seal ones that Dale has are really trick, but their cheif advantage is longevity.

aznraver

thank you guys the car is fully fonctionnal!! thank you!!