Hey guys I have just recently got done installing an sfr turbo kit on my rx8 and I am having issues with it idleing. I start it up, it revs up to 3k and the revs drop down then it dies. I have tried feathering the gas to keep it alive and the response seems very laggy. About a second after i blip the throttle it will respond and the revs will go up but then will drop back down and die if I dont keep bliping the throttle. I only did this for about 7 seconds as I could tell something was obviously worng.

Here is a quick list of everything I have done to better help diagnose the problem.

2005 MT rx8

Air pump delete- I capped the vac line and kept the resistors (unpluged at red harness by fender)

Relocated battery to trunk- I dont see any problems here as all electronics function properly.

SFR turbo kit- The tune I am useing was ran for a good amount of time on bayjs car so I don't see how the tune could be so far off that my car can't idle with it.

Other relevent mods: Sohn adapter, Turbo xs mid pipe and axle back, cobb accesport and tune, P2 injectores upgraded to 800cc.

I am sure I am leaving out some other information that could be usefull so if you have any questions just let me know. I have a few photos of my setup and a video of my first startup.





and here is a picture of how my airpump delete is setup.





In the video you can see some smoke. I think this might be the exhaust wrap? not sure though as I was in the car watching the accesport and gauges.

 

What is you g/sec airflow at idle?

What is your vacuum reading?

It sounds like your flooding rich on the car. So it is either fuel, air or spark. (Fuel - inj stuck open, too much fuel, or no fuel, smell the plugs to find out). (Air, maf reading too high or low, vacuum leak). (Spark, ignition not wired correctly, unlikely since it runs somewhat).

 

I havent gotten a chance to check, but I will tomorrow morning. I don't think that I have a vaccume leak but it is possible. And the ignition has not been changed since last summer when it was running properly NA.

I'm not sure if you watched the video or not but the car dies within a few seconds of start up. If I log the data for g/s and vac will it be usefull even though it dies right after?

 

Yeah. If it is stalling that means the compensation of the EMS cannot keep the car alive, it would be useful to know if it fuel trims, or airflow numbers are drastically different than normal.

 

Any chance you screwed up the wiring when you extended the MAF sensor wiring?

 

as in nicked or cut wires? I'm pretty sure nothing went wrong there. I just cut open the tubing and electrical tape and pulled the wires out, when I checked over the wires I didn't see any of them damaged.

Anyways I tried to start it up again. First try it fired up to 3k and died again. second attempt I feathered the throttle, this time the response was not lagging. I could blip the throttle and it would respond very quickly. I tried logging on both of these start ups but the car died while I was logging so the logs show nothing when I open them up. I tried a third time and didn't start logging until I could keep it running for a few seconds. I got a log thats about 5 seconds long that I will attach below.

During my first two attempts I saw Afr's between 12-16. In the log you see (third attempt) it shows Afr's mostly in the 20's. I don't know what was going on but seeing that made me not want to start it any further until I can figure this out.

I also took pictures of the plugs from rotor 2, leading and trailing.

Here is the leading plug after the three attempts to start it up.




I wiped some of it off. This plug is brand new.


Here is the trailing. this has about 2k miles on it.


Datalog should be an attachment that you can open up as a pdf.

Also my boost/ vac gauge is broken currently (needle moves with gravity when you tap the gauge) so I will order one this week and test it out next weekend.

 

So Kane to answer part of your question my g/sec is any where from 4g/sec to 21.9g/sec during my 750-2700 rpm "idle".

 

I don't think you're going to crater with no load ... it'll just lean out and die.

 

Yeah way over rich..... so vacuum leak is most likely culprit. Those plugs are pretty well fouled out.

 

do you have an air filter on it during these starting times?
The maf may be getting crazy signals if it is like what is pictured in the first picture?

This could be a lot of different things---injectors wiring mistake---easy to do!
maf signal is wack
stuck injector
etc etc
I hope you have good luck in this troubleshooting. meanwhile you will be learning a lot.

 

Thanks for all the responses guys. When I get home from school on friday I will check over everything to see where any vacuum leaks might be.

olddragger. I didn't have an air filter on, the one that came with the kit is trashed so I am getting a new. I'll add that to the list to get for next weekend.

I only messed with the P2 injectors which don't come in to play until higher rpm ( correct me if i am wrong) so this should not mess with the idle correct?

Thanks for the help guys.

 

So this weekend I installed my new boost/vac gauge and got a new airfilter. I also used a compressor to pump air in to my intake to try and find any vac leaks with soapy watter. I didn't find an exact spot but I have it narrowed down to this area.



The air is flowing up and out in the direction of the arrow out of the circle that I drew. There werent any leaks on the UIM. I could just feel the air rushing up out of this area so I pulled the UIM off to investigate. I couldn't see any loose hoses or obviouses areas that would be leaking. the only stuff I took apart in this area during my turbo install was the UIM fuel rail and p2 injectors. I instpected the injectors while I had the UIM off and they were fine. So I put everything back togeather and tried the compressor again. Air was still flowing up and out of the same area.

Any ideas on where my leak might be?

 

Where the secondary UIM meets the primary UIM???? That o-ring is in the vicinity.

 

I checked all the UIM o-ring/ sealing points and didn't see any bubbles or feel any air escaping there. It felt like it was coming up from under the UIM.

 

read this
https://www.rx8club.com/major-horsep...uff-up-211884/

 

I have read a bit of that thread already but I just went through it again. Are you thinking i might have the omp and jet air hoses setup incorrectly? As i Have it now both are plumped back in to the intake between the maf and turbo with a check valve in the jet air hose letting air flow in to the hose towards the engine.

 

sounds like you have it sussed - just thought it would be worth checking .

 

You can't just shove a tune from another setup in and expect it to work . That said it is unlikely the tune is the reason for the idle issue.

 

So I fixed part of my problem tonight. One of my injectors wasn't seated correctly and thats where my major vacuum leak was. So i fired it up again and still it will not idle on its own. It revs up to 2k and as it settles down it sputters then picks itself back up. its cycles from about 1,000 rpm to 500 rpm back and forth for about 5 seconds before it finally dies.

Skip 28 seconds in to get to the point.

So I think I might have vacuum leaks else where. any other ideas on what might be causing this?

by the way the smoke is an exhaust leak at the v-band clamp from turbo to down pipe.

 

I understand that the tune will not be optimal but I figured it should be close enough to idle. Also I loaded the stock map and tried that tonight. It resulted with the same symptoms as the turbo specific tune as i described in my previous post.

 

have you tried driving it around till fully warmed up and see if it improves enough to stay running ?

 

You might wanna perform the de-flood procedure first. IE. crank with plugs removed and e-shaft sensor disconnected.

So even with the factory stock non-turbo rx8 tune it won't idle?

It should at least idle with this tune. Don't rev it into boost though.

 

I will try the de-flood procedure and then try to keep it running untill its fully warmed up and see if that will help any with the idle issues.

correct. with the stock tune it has the same symptoms as the turbo tune and dies just as quickly.

will report back after I try this.

 

I would have to look at other SFR setups but to me it seems like the maf is too close to the air inlet. All the turbulence would cause these types of issues.

 

9k- from the other turbo setups i have seen and read about I also thought the maf was close. I read that the minimum distance from filter to maf should be 6" of straigt piping. maybe this is part of my issue. I did send some pictures of my setup to Tim at SFR and he said that the piping was setup correctly.

Anyways today I fixed all the vac leaks I could find (only one other minor one). I then took the plugs out and cleaned them up with carb cleaner and a toothbrush. I also did the deflood procedcure. I installed the stock rx8 plugs and the stock rx8 tune. I started it up and it was exactly the same. I held the idle as constant as I could around 2k rpm and got the coolant temp up to 180. idle didn't improve at all. I took a few datalogs while I was warming it up, the first one is when the engine was still cold and the last one is when the engine was up to temp.

I took another video after I shut it down (had to get phone). second start up (after it was up to temp) was a lot harder to keep the idle at a constant rpm.

sfr turbo idle issues - YouTube

I also took pics of the L and T plugs from rotor 2 after the two start ups to see how they looked after I cleaned them.

The residue on this plug (trailing) was a little bit gritty feeling.