blu1985

First up, I would like to appologise if i'm wasting everyones time. Though i would also like to thank anyone that may have some useful advice to offer, you help will be greatly appreciated

I have had absolutely no experience with rotary engines

The problem is with my brothers 1/89 model Aus spec N/A RX7 s4.

Was boiling coolant to start with, found the radiator cap (not filler cap) was not holding pressure. Fixed that problem. But still runs a little hot for my likeing (gets over half when stuck in traffic or pushed, sits just below half at the best of times)
(I'm thinking water pump/radiator might be poor)

Next problem is that it makes no power above 5000 rpm
Its doesn't cut out, its just that the power drops off gradually up until its making nothing near 7.

Put on chassis dyno and here are the results
Peak kW: 58.1@5000........ only 46@6600
Made about 120Nm at 3500 but descends in a steepening curve after that

After a quick look through the manuals i've noticed that the air pump is gone

From all the manuals i have found through this site i have not found actuators that are like the ones in this car........... The actuators on this car have no external connection for air pressure to be applied to but the have ports where they attach to the intake that require vacuum to operate the actuator.

Since i cant find this system in any manuals and i don't know anybody that knows anything about rotarys i'm having a bit o trouble figuring out how the actuators should be operated.

One more thing to throw in the mix.....

My brother came home today after a drive and said car cut out just after 4000 rpm consistantly.
Went out to have a look and noticed that he had run the fuel down to the point of the light coming on........
Does anyone think that the Fuel pump / Running lean could be the cause of both problems??? (The hot running and low power, i'm not even sure what conditions are needed to operate the 6PI actuators)

l4nc3r

The actuators on the S4 are activated by exhaust back pressure. There is a tube that come back up to your engine thats quite noticeable. It usually connects to your pre-silencer/cats. If it's not there, you'll need to fix that. I would also take the 2 actuators off and see if your hand can freely move them. If not, then they need to be replaces(I tried to free mine, it wouldn't for me.) This could most likely be your problem with his car not getting any power at 5000. If the actuators aren't opening, then your not going to get much above 4k.

Your overheating problem now. If your car is missing the airpump, GET A DUAL PULLY for your alternator. With the airpump gone, your water pump only has 1 belt running it then 2 belts, and they do slip if you dont have 2 on it. There $50 on Mazdatrix. I would recommend getting one. But other then that, these cars do run around 1/2 I've noticed(Turbo's mostly though.) Mine runs around 1/3 and sometimes below. Change the hoses, flush the coolant system with some coolant flush. Then refill with coolant. I do 30% Coolant and 70% Water during the summer and 50/50 during the winter.

pfsantos

iTrader: (1)

Careful - Australian and some European spec. cars have some differences in intake setup. The 6PI system is one of them. Please look in my sig. for the link to th training manual (this is not the FSM). It shows what the OP is talking about. I was surprised (to say the least) when I first found out about this. I didn't study the system in detail, and don't remember the exact activation method. I also noticed the Secondary Air Injection system is different (maybe absent - don't remember now). PM me or post if you want me to study it with you.

BTW, I recently posted some info on the North American spec. S4 6PI (6 port induction) and Secondary Air Injection systems. Search advanced with my name under poster. Others have also added good info.

l4nc3r

Huh, thanks for the correction PF, I didn't know there was a difference. I will have to read up on it.

pfsantos

iTrader: (1)

It's cool l4nc3r - I only found out about the training manual about a year ago.
I stumbled about the other info, because the Fuel and Intake Systems intrigue me and I was looking through.

I'd really like to find an FSM from Europe or North America. That would be cool. I'm sure there are other things different (like the bumper mount rear fog light in Europe)

greensix

there are two different type 6pi system...one is for australia and another one is for other countries...and the actuators are in different type...i have the manual talking about that...you can give me your email, i can send it to you if you dont mind..


and i have one question about 6pi system...
the question is that....
if the 6pi system is ON....will the acceleration have a great change just like V-tec of honda?? i am not sure whether the 6pi system of my car works...how to test it???and what rpm it will be ON???

blu1985

Thanks guys, that training manual would be great but i can't see the signature... (only my first post) any other way you can give me the link

RotaryRocket88

iTrader: (7)

greensix, the 6PI gets activated at 3800 RPM, and will be very noticeable above 4500. It has a definite pull up to redline.

Testing on an S4 isn't easy, but can be done by smearing some grease on the actuator rods or even a zip tie. Go out and take it for a spin, and check back to see if the grease/zip tie moved. On an S5, you can just open the throttle and watch the actuators. They wil snap open at 3800, even with no load.

blu1985

Thanks guys, that training manual would be great but i can't see the signature... (only my first post) any other way you can give me the link
blucas@gmail.com

blu1985

Got the Training manual now..... that was heaps of help thanks

Gunna check the exhaust back pressure line today along with a check of fuel filter and pump (don't have a fuel pressure gauge at the moment so will only be able to check flow)

EGO sensor is unpluged also and i cant seem to find the connector anywhere.... probably just going blind........

Will post results...... and thanks again

blu1985

Applied pressure to the actuators and found that the front one works ok and the rear doesn't (though i think the exhaust is not generating enough back pressure to operate the front one due to the exhaust pipe being split in half just after main cat. converter )......

Removed actuator from rear valve and found that the valve is quite hard to turn and tends to stick in certain spots..... anyone got any idea how to free it up without removing entire intake manifold. I've tried CRC and moving it back and forth but it has only freed up a little bit..... still much harder to turn than the front

ramses666

iTrader: (1)

Really only two choices - keep spraying & working it or take the manifold off. It's not that hard to remove it. Just make sure the manifolds are properly sealed & all hoses are correctly attatched when you are done. Probably a good idea to replace all vacuum lines and have injectors cleaned. Might solve some of your troubles, but then again... it's a can of worms you might be opening....

Most of us have a-spec(american specification) vehicles and yours is slightly different than ours. Try the Kiwi-Re website. They might know the exact differences.

Ramses666

blu1985

Thanks ramses, thats about what i thought.
With definitely try the Kiwi-RE website

pfsantos

iTrader: (1)

+1 On removing the LIM. There'll be some deposits on the valves anyway, and it's good to clean them properly. Carb. cleaner works excellent.

greensix

thank you so much...
i dont feel any difference above 3800 rpm even above 4500 rpm....
but i found out something..when my car doesnt start...the throttle of 6pi is opened..when my car starts, it is closed...is it normal???

and will the sounds of engine change if the 6pi gets activated??

Skidtron

iTrader: (1)

Uhmm. You stated your car was a 1/89 meaning jan 89 which means that car is an S5 because it was built on that date not sold on that date. So really you have a 90 rx7 GXL S5.

If your engine is like the USA version you need to have a working air pump and the pressure is used to open the ports via the actuators. One easy way to find out is to look at the ACV the nasty looking thing on the intake manifold just above the exhaust manifold. Is there a nipple protruding directly from the side of it near where the air pump hose attaches? If so it's a S5 and thats where the pressure source is. But it doesn't go from there to the actuators. it goes to the 6pi and vdi solenoids first then comes back to the respective locations.

Note: when the 6pi is activated there is no noticable reduction in torque all the way to redline. The engine doesn't change sound or pitch like vtec. It just sounds super smooth all the way up and the tach doesn't slow like it does on your car now. You'll know its on it's obvious i would guess around 20 hp or so on teh big end

The reason nobody is answering some of your questions is they don't know and damn near every na rotory doesn't have working 6pi that I've come across. I fixed 3 last month.

If indeed you do have a S4 you litterally attach the hose from the exhaust to the ports.


If your intake manifold looks like this then its a S5 if not ignore all I said. Just trying to be helpful

HAILERS

GREENSIX has a 1986 non turbo RX. He mentions "the throttle of 6psi" in his post. That gives us a hint that he has the version of 6PI that is not similar to Aus and USA versions. It instead uses a *shutter valve* (butterfly) rather than the sleeves used on the USA version. He lives in MACAU, a bit east of Tx.

His are operated by intake manifold pressure or lack of pressure. That vacuum is operated by a 6PI Solenoid. The shutter is CLOSED during low and medium speeds. So now greensix knows why the 6PI throttles are open prior to starting the engine and closed once the engine starts up. See Training Manual.

blu1985

Cheers skidtron....

Looks like i'm on the right track then...
Only 20hp i was hoping for 20kw

It definitly was built 1/89 but it is definitly a series 4.... not just the engine the bodywork is series 4 too.

Would also like to thank whoever went to the trouble of scanning the FSM and FTM..... i never would have been able to figure it out without them.

I'm an apprentice motor mechanic but this rotary stuff is all new to me