Just rebuilt my motor at 170k miles. Long story short, both housings were bad(replaced with new housings), rotors were good , e-shaft was good. Ported the motor.Used the Atkins rotary kit B for the build. Buttoned it up yesterday, took 3 sets of plugs to burn off the hylomar.

The Good:Starts up on a dime, starts up when warm or even hot after driving it.

The Bad: Can't hold idle.

This morning it idled for 3 min before giving it gas and it died.Drove the car to work on the highway for an 1 hour commute to work. My 8 drives strong, I don't drive it pass 5500 rpm, although I blipped it to 6500 on the on ramp. No problems, no over heating problems,nothing. Just when coming to a stop light it dies. No check engine light either so that tells me that my electrical hook ups are fine.

Could I have crossed a vacume line somewhere? The RX-8 shop manual doesn't give a clear diagram of where all the vacume lines go. I know it takes a few cycles for the ECU to learn but I would of thought a 1 hour drive on the highway and in town would have caused the ecu to learn by now.

Do i be be patient and wait for the ecu to learn or could it be something else? New coils, wires and plugs are on the car.

I'll post pics tomorrow.

 

Eh, I would give it a few more drive cycles. I dont know the exact length of time that is required for the ECU to adjust the proper trims, but I know some guys have had to go a day or two before their idle came back to normal.

 

Ok will do, thanks.

 

Ok after the third day my CEL finally came on. Its read the random misfire code and a new one I haven't seen before.

code p0506 idle air control system rpm lower than expected

I looked through the manuals for a clear picture of what the IAC may look like, through my searching I found nothing.
Does anybody have a diagram or can take a picture of there own IAC in there car. Im stummped.

I am starting to think my coils may be starting to take a dump since I tried to start the car for about a half of day on Monday to get the hylomar out the motor. I will put some new coils in when I get home. I have about a 1000 miles of breaking in to do. Still the car starts up on the dime , a little hesitation when at the gas pump this morning. But pulls like a bull and drives very smooth. Only taking it to 5500-6000 rpms.

I'll skip the boring pics of taking the motor out of the car.





Sorry for the fussy pic. Bottom apex seal is broken length wise.


Buddy cleaning up the housing to see what were working with.

 

Open and inspecting the motor


Cleaning and doing spec work




My garage


Cleaned and speced out rotors

 

Severe chafing on the rear rotor,we noticed this happen where the fuel enters the top of the housing. Cool spot of the motor,where the temp is considerably different than the rest of the housing.


Outer edge of inner housing is toast


Fresh brand new housings!


The rebuild of the first rotor

 

Lost the pics of building the rotor up with the seals and springs. Here is the after effect and the rotor being fitted in the new housing.


End of one of the rotor builds, installing middle and larger ring with rubber seal


Installing Apex springs and seals

 

Lost the pics of building the rotor up with the seals and springs. Here is the after effect and the rotor being fitted in the new housing.


End of one of the rotor builds, installing middle and larger ring with rubber seal


Installing Apex springs and seals

 

Steady hands and having the patience of GOD installing the Apex seals and springs.






Louie is deep concentration, motor almost done


Trimming side seals

 

I got the same code whenever I disconnect the battery.
Give a few drive cycles and it'll come back.

 

Really? So is there a IAC valve on our car?

 

Closing it back up

 

Going back in


And that is my build after 170k miles. 30 hours of work and a wealth of knowledge gained. Ports I didn't show in respect of the builder's request. But I will say it makes that brap ,brap , brap sound we all come to know and love.

I'll post vid soon once I get my idle straiten out.

 

looks good
thanks for sharing pictures

 

RedDozen? I am not following you?

 

Good luck with the results! now bury yourself in the service manual and have fun discovering what may be wrong with that code.

A few tips for your next rebuild, don't take them the bad way as it's rare to have all the right tools the first time:
Use way less assembly lube.
Don't grind the side seals that way, use a bench grinder. Way better results and your fingers will be thankful.
The paint pot as a working stand is fun to watch but a proper stand or a work table would be a smart alternative.

 

Yeah that engine stand/5 Gallon bucket is scary. But the drilled holes around the port are even more scary.

 

^Yea I peeped that out as well

 

Oh lord, i just noticed them. Jeez... time to rebuild the rebuilt engine with new sideplates!

 

Cant even see 1/2 the pic.

U said u tried to burn hylomar off, i wonder how much did u put, u dont need too much of that stuff.

U grind the side seals with ur hand? Its a nightmare, i am thinkig to setup a drill press thing just for thi spurpose.

 

The porting will affect the idle....mine needed tweeking before it was happy after the porting

The IAC code is related to the throttle body...that is what controls the intake air circuit at idle..might want to swap in another one to try

Not sure about the drilled bridgeport thingy either.....

Neat trick with the apex seals is a very small amount of cyanoacrylate glue ( Krazy Glue)....works wonders with that end piece

Someone must have shares in Vaseline too

 

What did you tweek to regain idle?

Didn't have a alot of time to dig into the idle issue. I changed out the coils which helped smooth out the rev band.

The 5 hole bridgeport may be throwing off my idle as well.

What is crazy is that when removing the TPS sensor the car idles fine. The negative resullt is no throttle response at all. Revs slowly creep, but the car idles at a healthy 900-1000 rpm. Is there a way to fool the computer?

I read a few post about the crank pulley wobbling which could cause loss of idle or worse not even let the car come on at all. I have a little play but no worse or better before the build. The E-shaft sensor is clean as a whistle. My 3 sensors under the intake are in the following order, blue, white black. Which is the correct order. I will need to make sure the vacume lines that are going to them are in the same order, since they are color coded with a small dot.

If everything checks out and the fuel injector connectors are in the right place , the only thing I can think of that will fix my idle issue will be to buy a Cobb Acess Port and reflash the computer to adjust to the new port job.

Other than that my car pulls hard and drives fantastic. And the new sound under WOT is intoxicating!(I took my car to 9,000 rpm one time to make sure everything is ok at the top rpm rev range, 500 miles to go to full break in)

 

You're doing no break-in at all basically.... that's not good.
The shitty bridgeport may be enough to upset your idle. Why did you ruin a decent rebuild with such a crappy port job?

 

Bse50 thank you for the info on the code. Also I downloaded a service manual.

The side seals on the rotor don't interact with those ports,and the side seals by the pac mans goes over the ports quite nicely. The work was put in to make sure there would be no interference at all.

All i can say is this. A real bridgeport won't work on our motors, unless you do some serious cutting and adding materials.You know this and that topic has been beaten to death like a dead horse.

The 5 hole ports work, .... look at it this way, I could be the ginny pig in this porting effort that could be a learning experience for all.

I can honestly say , if the idle issue wasn't a problem , the car would be perfect.No over heating, no gas smells coming into the cabin. It drives great, throttle response is better , and it pulls much harder than stock. I have full function of my A/C. Sounds unbelievable at WOT.And my gas mileasge hasn't improved or gotten worse. So in my book that is a win!

I'll keep updating my progress/ problem history on this thread every 1,000 miles. 800 miles into my build and the idle is my only problem so far.

 

After a tune (go buy an accessport!) we will know more.
However there is more to intake ports design than just "volume". Their shape is just as important (if not more, to an extent), the way the air goes into the chamber is vital, too.
Think about the difference between farting and gently blowing.Intake charges generally like the latter.

Don't get me wrong, I applaud your effort but being a guinea pig requires a lot of money, knowledge and time. Knowledge wise you're still lacking so starting off with an unknown learning base (weird porting) isn't the easiest way to learn.
Think about doing complex equations before learning additions and subtractions
To do this kind of stuff i would have used better tools, too. How did you pick up hole locations? Is there a logic to this? Since there's no way to really individually tune the front and rear rotor in your case even a .5mm difference in the porting can play a role.
That's definitely not the kind of build you want to do on a bucket with free hand grinded seals and way too much assembly lube...

If you read what i wrote in your other thread... picking the right builder is crucial