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-   -   s5 intakes on s4 engine help (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-intakes-s4-engine-help-985502/)

Redline420 01-28-12 10:44 AM

s5 intakes on s4 engine help
 
thats what my engine came with, and when i got it, wouldnt idle below 3k
i have however been chasing other kremlins, vacuum leaks, dirty injectors, plugs, wires.

could this be keeping my car from idling? just met the only other rotorhead in my town and he said yes! hes also got a couple parts engines, plus lots of the knowledge about these that i am lacking.

i think im going to have my car running soon, there cant be much more to it.

or maybe this s5 fuel pump is pumping too much fuel.

both in conjunction with my dual streight pipe exhaust keeping me from running?

im not sure which gaskets to order, s4 or s5 until i get a definitive answer on this s5 intake deal.

cheers

Redline420 01-28-12 11:33 AM

sure would be nice to use these s5's as ive put alot of time and effort into them alone.
used some pretty expensive cleaner and got the internals as smooth as i could without a polish. but tbh if i have to put s4s on il do the same but i will probly polish the internals, logo wont look as nice though.

http://a4.sphotos.ak.fbcdn.net/hphot...66205447_n.jpg

Derekcat 01-28-12 02:25 PM

http://homepage.mac.com/carldavis/intake.html

Something else isn't right, simply having the S5 intake on wont cause any problems that way.
Check out the perfect idle thread in the archives, it goes through everything you can do to make it awesome.

satch 01-28-12 03:03 PM

The S4 has the Air Bypass solenoid for the 3000 rpm cold start up while the S5 has the Accelerated Warm Up Solenoid. Whichever one you have is likely activated on a continous basis. Tell us which one you have. If you have the S4 component then there are two wires running to it where one wire is Black/White while the other wire is Brown/Yellow. The B/W wire has battery voltage w/key to on or engine running and the Br/Y wire should only have a ground for 17 seconds after the cold start and then thereafter there is no ground. If you had a continous ground on this wire the idle speed would be elevated.

Redline420 01-28-12 06:05 PM

Il elaborate on the idle issue, id have to hold my foot until 3k rpm for it to run, added fuel system cleaner and managed to get it to run at 2222 rpm, decided to clean injectors one primary was stuck open, cleaned intakes, put it back togather with old gaskets no rtv, wouldn't run.

waiting to decide which gaskets and intakes to use before ordering from Mazda or mazdatrix.
I think all the s4/s5 na intake gaskets are the same not 100% yet.

Can a second person assure me I can run these intakes?

Derekcat thanks for that DIY its very informative nice pics good reference for my first build.

Brb gonna grab pics before edit lock

RotaryRocket88 01-28-12 07:06 PM

2 Attachment(s)
Your symptoms suggest a vacuum leak. When I converted my S4 NA engine to use the S5 manifolds, I initially did not grind enough metal off of the rear iron. This kept the UIM from sealing against the LIM, which made a large leak.

The S4 and S5 UIM/LIM gaskets are different in one way: the hole for the rear stud. The ports line up the same, but you have to modify an S5 UIM to bolt down to an S4 LIM. This is mine. Notice that I had to grind down the side of the rear intake runner to make room for a 2nd hole in the flange.

https://www.rx7club.com/attachment.p...1&d=1327798867

Since your UIM looks untouched, I'm assuming you have an S5 LIM bolted onto the engine. This will work fine, but the passages to the exhaust ports will be blocked off, which means you will not pass any smog tests (if needed). There are pictures showing this in the writeup linked to above.

Something else that may be helpful is the S4/S5 hybrid vacuum diagram I made when I was doing this conversion. The EGR solenoid has to come off the rack, but you can't use an EGR with this manifold anyway.

https://www.rx7club.com/attachment.p...1&d=1327798867

Redline420 01-28-12 07:42 PM

the solenoid has been moved` its now unmounted just kickin it.
http://a4.sphotos.ak.fbcdn.net/hphot...11394190_n.jpg
dynamic chamber was shaven to fit?
http://a4.sphotos.ak.fbcdn.net/hphot...91899462_n.jpg
more pics of the "block"
http://a6.sphotos.ak.fbcdn.net/hphot...07469625_n.jpg
http://a4.sphotos.ak.fbcdn.net/hphot...35427609_n.jpg
cant find wire for this on THIS side of engine, got one on driver side though hmm
http://a2.sphotos.ak.fbcdn.net/hphot...97509279_n.jpg
thanks for looking.

i think il just assume its gonna run with new gaskets, not sure what stage of de-emissions control this car is at, some of this stuff is sinking in though, thanks guys.

Redline420 01-28-12 08:40 PM

in my first picture i show two parts of the upper? intake manifold, i have one hose outlet plugged on the left section, the outlet that meets part of the fuel injector inlet. the one on the left is plugged and the one on the right doesnt flow like the others.
is there any more dissasembly i can do with this fuel injector inlet thingy to clean it up in there?

RotaryRocket88 01-28-12 10:48 PM

That is not an S4 engine. It's S5. Notice the flat spot on the top of the center iron? That's where the EGR valve would be on an S4, which is why you have to remove it when using an S5 manifold on an S4 (it would not fit underneath). S5s did not have EGR valves, so the passageway is missing from the casting.

For your last question, I think you mean the injector air bleeds? These just need a metered air source (air from before the throttle plates), and in my setup I just tee'd into a line coming off of the back of the TB, and ran a split line down to both secondary injector bleeds. It's in my diagram. The air helps atomize fuel as it exits the injectors.

Redline420 01-28-12 11:23 PM

s5 now? lol it changes daily, i have metering oil rod up front maybe cause s4 ecu couldnt provide the electronic meter? man im lost with this engine, should i get more and more pics, how certain are we this is s5?

injector air bleeds hmm sounds like the part im describing yes, i must get mine flowing better :)

tyvm in advance

13bpower 01-29-12 12:20 AM


Originally Posted by Redline420 (Post 10956811)
s5 now? lol it changes daily, i have metering oil rod up front maybe cause s4 ecu couldnt provide the electronic meter? man im lost with this engine, should i get more and more pics, how certain are we this is s5?

injector air bleeds hmm sounds like the part im describing yes, i must get mine flowing better :)

tyvm in advance

It is very easy to build a frankenstien engine for these cars. It is actually very common. You can swap s4,5,6 rotors, housings, plates in most builds. Your sounds like it might have just been someone dropping a s5 engine into an s4 chassis and what had to be modified to get it to work was..... or wasen't and is/was causing your 3k idle.

Redline420 01-29-12 10:32 AM

Word from the selling is this engine ran mint for about 15,000km
When I bought it the fuel system was contaminated, thick sludge in fuel tank, that's why I took intakes off in the first place, chased the gross all the way to the injectors, they were gross too.
Looks like these intake gaskets are all the same, I think Il order some from the group buy section, cheaper than mazdatrix it looks like.

Redline420 01-29-12 12:50 PM

btw rocket, your aluminum intakes look rad painted up, red vac lines damn nice too

im pretty sure the plugged primary is what was keeping it from idling, it was stuck open until i cleaned it.

thanks everyone for the insight as to what the heck setup ive got going on.
im super new to rotary, all the advice helps, most of it sinks in, and some of what i retain i can even apply :)
going to wait on gaskets before i button her up, and get those air injector bleeds flowing better, without damaging plastic insert deal.(advice? aok :)

SpikeDerailed 01-29-12 06:05 PM

http://a4.sphotos.ak.fbcdn.net/hphot...91899462_n.jpg

I didnt look that intently at all the pictures. But on my throttle body there is a vac nipple where the hold is on yours between the two lower tb bolts. May want to make sure that is not a vac leak.

hiroichi1515 01-30-12 09:35 AM


Originally Posted by RotaryRocket88 (Post 10956526)
Your symptoms suggest a vacuum leak. When I converted my S4 NA engine to use the S5 manifolds, I initially did not grind enough metal off of the rear iron. This kept the UIM from sealing against the LIM, which made a large leak.

The S4 and S5 UIM/LIM gaskets are different in one way: the hole for the rear stud. The ports line up the same, but you have to modify an S5 UIM to bolt down to an S4 LIM. This is mine. Notice that I had to grind down the side of the rear intake runner to make room for a 2nd hole in the flange.

https://www.rx7club.com/attachment.p...1&d=1327798867

Since your UIM looks untouched, I'm assuming you have an S5 LIM bolted onto the engine. This will work fine, but the passages to the exhaust ports will be blocked off, which means you will not pass any smog tests (if needed). There are pictures showing this in the writeup linked to above.

Something else that may be helpful is the S4/S5 hybrid vacuum diagram I made when I was doing this conversion. The EGR solenoid has to come off the rack, but you can't use an EGR with this manifold anyway.

https://www.rx7club.com/attachment.p...1&d=1327798867



Hate to thread jack but what part has to be grinded down on the iron. I spent the entire day trying to track my vacuum leak but couldn't. I dont see anything obvious that could be causing problems. Although if I spray starter fluid under the intake manifold it starts to rev. The egr spot has a block off plate. The oil injector holes are blocked. Fuel injectors seated using fuel hose rather than the rubber grommets. The only thing that makes sense is the intake not fully sealing. I can't hear air being sucked in because I dont have a cat back so the car is insanely loud. Anyway, thanks in advance for the help.

sbrmechanic 01-30-12 09:23 PM

would there be much of a power gain by just adding an s5 intake on an s4?

RotaryRocket88 01-30-12 11:28 PM


Originally Posted by Redline420 (Post 10956811)
s5 now? lol it changes daily, i have metering oil rod up front maybe cause s4 ecu couldnt provide the electronic meter? man im lost with this engine, should i get more and more pics, how certain are we this is s5?

It could just be an S5 engine adapted to be run on S4 electronics. Swapping the front cover and TB to use the mechanical MOP is common practice. The alternative is premixing 2-stroke oil and blocking the MOP off.

Or it could be a franken-engine, as suggested above. Some pieces could be S5, such as the center iron.


Originally Posted by hiroichi1515 (Post 10958411)
Hate to thread jack but what part has to be grinded down on the iron. I spent the entire day trying to track my vacuum leak but couldn't. I dont see anything obvious that could be causing problems. Although if I spray starter fluid under the intake manifold it starts to rev. The egr spot has a block off plate. The oil injector holes are blocked. Fuel injectors seated using fuel hose rather than the rubber grommets. The only thing that makes sense is the intake not fully sealing. I can't hear air being sucked in because I dont have a cat back so the car is insanely loud. Anyway, thanks in advance for the help.

There's a picture in the writeup above. A small piece of the clutch inspection plate has been cut off, and the top/middle of the iron has been ground. It's silver in color since the oxidation has been removed.


Originally Posted by sbrmechanic (Post 10959341)
would there be much of a power gain by just adding an s5 intake on an s4?

Yes, click the writeup link above. It describes the VDI system, which extends the torque curve above 5200 RPM.

hiroichi1515 02-03-12 06:36 PM

After grinding that spot for 30 mins, no more vacuum leak and steady 1k idle. I am now one happy camper!!!!

SpikeDerailed 02-08-12 11:11 PM


Originally Posted by RotaryRocket88 (Post 10956526)

So the top vac. nipple on the firewall side of the plenum is metered air for the air bleed sockets?

RotaryRocket88 02-09-12 02:01 PM

Yes, the top nipple is a metered air source. Just be sure you're using the S5 TB spacer to properly direct flow. I tee'd into the line going to the PCV, and then tee'd it again for each of the secondary injector bleeds.

The bottom two nipples are vacuum IIRC.

mmendenhall 03-12-15 07:36 PM

Where to grind
 
I think i must be blind cause im in the process of switching to an s5 intake where is the spot your have to grind out?


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