Im new to this Rx7 game...
Just bought a non turbo Mk2 one... 13B it says on the intake manifiold
My Problems are the following...

When the car hits 4K rpm It Just doesnt want to pull on any more... Revs on But has no power...

Somethimes the car is very Jumpy...

It uses enourmous amounts of fuel...

Here is a list of the things that i have done to the car so far..........
The exhaust on the car was totally rotten when i got it So I made my own System form the start of the manifold to the back...It std bore But of a free flow design with no cat... I took off all the air pipes (which i now realise was prob a abd idea)

Was reading about the 5th and 6th ports hoe they can be dirty so have the entire entake system sittin in pieces in my garage now...It is pretty dirty But Can still move freely...
(going to clean it all now...)

A few questions... How are the 5th and 6th ports activated???
How are the 2 aux injectors opperated???
Is there any way of Taking off the 5th and 6th Flaps and all that air injection stuff???
What are the benifits of doing any of the above...???
any Other sugestions very welcome Cuz i dont know alot about theses engines at all...
thanks
Richard.........

 

exhaust backpressure activates the 5th and 6th ports. The secondary injectors are activated after 3800 rpm iirc. A lot of people wire their 5th and 6th ports permanently open to save the hassle of them sticking at the cost of low end torque.

rotaries are gas guzzlers period. the only way i have seen them get better milage is with a good tune up, grandma driving, or getting a standalone ecu with precise fuel maps and whatnot to make ultimate cruise efficiency.

 

Does the "check" engine light come on during the test cycle when you first turn on the key?

Does it come on (even briefly) while driving?

I have a mirror set of the factory service manuals on-line at the link in my sig below..

 

Will there be sufficient Back pressure in A free flow exhaust to opperate the 5th and 6th ports???
Its std bore but has 2 staright through back boxes instead of the huge std ones...And no Cat...

Are those ports Ultimately vacuum opperated??? How do i keep them open???
Engine light does not come on at all..

 

On the 5th 6th ports, there is a little tube with a banjo bolt at each end that feeds the air to the actuators. The tube from the split air pipe attaches to it. It runs between the exhaust manifold and the lower intake manifold. Make sure it doesn't have any holes in it. On my GXL it was rusted through, thus the actuators didn't work. Replaced it with one from the junk yard that was in good condition and the ports worked great. Only cost me $5, but it's a little hard to get off and on.

 

No, there is technically not enough back pressure to open the ports. There is a "presilencer" that racing beat sells that has a split air pipe built in that will make enough power to open those ports. It's pretty much straight through.

Now, there are other ways to activate them. Most are using a small electric air pump, like a fish tank pump to creat about 5PSI on an RPM switch that will kick those ports open at 3800 rpm. You need to search on this forum. There are several detailed write ups on how to do this. Get a new fuel filter, that always helps a ton.

 

What year is the car?

 

It'd be s4 since he said it says 13b on the dynamic chamber.

 

sounds like the cats to me

 

not its not an S4 jsut becasue it says 13b
it could an S5 also or a 1st gen GSL-SE but since you are in the 2nd ggen forum we will discount the last one
if you know your year it would be a lok better for us to help you out
the more infor you provide about your car and what is going wrong the easierr it is for members to help you and when all else fails use the SEARCH function
you can find just about anything in that

 

its 1989...
I am assuming the ports which you are refering to are the 2 flaps in the lower intake manifold???
Do the ports stay open when the car is turned off??? I have the manifold off and they r open... it takes suction to close them???

 

Well ****. I own an s5 and never noticed that. *meh* He said he's in ireland. The S5 n/a was never released in europe. So, that works too.

 

Really... are you in the states? or did this car come from the states? According to higgi, there were no european Series 5 n/a cars.

 

its a Uk car as far as I know...
Normall aspirated 1989...

 

Does it have a distributor or a CAS?

 

well the S5 models 5th and 6th ports open differntly thean the S4 does

the S5 dont use backpressure to open the ports like the S4'd do
im not sure what the S5 uses cuz i dont own one i own an S4
but i think its just a valve like the fishtank motor thing people are talking about
i think they open at a certain rpm
im not sure so if i am wrongplease dont flame me and please correct me
i hope this helps out some
and i thought only US an Canada got the N/A models
i thought the rest of the worldd got the Turbo models
guess i was wrong

 

They use a split air pipe just like the s4's.

 

It has a distributor...

Just discovered i have a dead injector...
i unpluged the 2 aux injectors and the car litterally woulnt rev over 4K...Then pluged them in 1 at a time... went as well with the one nearest the firewall pluged in as with both pluged in... So im guessin I have a dead injector...
What other jap car has similar injectors??? there are no Rx7s here...

 

Also noticed it takes the car a few seconds to actually stop when u turn the key off... are they suposed to do that???

 

If it has distributor, its regular european S4 (88 model year). If your papers says its 89, it says year of first registration, not model year, as its usuall in europe.

 

No, properly working it just shuts of.

 

You might have faulty resistor pack. It did happen on one of our cars (same setup, european S4 NA), and was doing same way. Primaries working ok, secondaries not.

 

These are a starnge complicated car... Every time I think i understand something about it I dont... :p

There is a signal going to the secondaries... Tested it with a spare injector...It pulsates after 3800rpm...
Im guessin a dead injector would leave it somewhat dead up top...

Also i thinK I may have an oil keak around the oil injectors... I can smell oil when engine running...