<p>Hi Guys/Girls, I have been having some idle problems for a while and have exhausted myself and still have no solution. I will try and describe my problem in as much detail as I can and then give you as much information about the car as I know. </p>
<p>In any situation that the car is idling (start up, lights, stop signs,...) it surges from around 800rpm up to around 1600rpm several times before it eventually stalls out. At first start up of the day, or after its been sitting for several hours the car starts up fine and revs fairly high to about 2000rpm and stays there for about 15 seconds before going into the idle surge problem. </p>
<p>Now for the car, and everything I have tried. It is a July of 2003 build with 147,000 miles on the body. I have recently (within the last few months) replaced the engine with a used one I had purchased from a local forum member that only had 7,000 miles on it since it had been replaced by mazda under warranty. The original engine in mine was preforming fine, but with 140,000+ miles and the replacement being a very good deal I thought I would go ahead and do the swap before I had any problems since my RX8 is my only and daily driven vehicle. The swap consisted of the recently refurbed engine, all peripherals (alternator, starter, pulleys, belts, etc...) transmission, headers and cat back, and an AEM intake. I still have everything that was removed from my car and as such I have swapped, cleaned, or replaced several parts in search of an answer. Thinking it might be a vacuum leak, I checked all of the hoses, cleaned and then swapped all upper intake manifold pieces, tried 3 different throttle bodies, tried both OE intake as well as AEM, cleaned and then swapped SSV actuator and switch, swapped 2 different ESP sensors, even removed the air pump and capped the exhaust port for it. I am seeing both a p0661 and p0410 trouble codes hence why I replaced the ssv items, but still getting the surge. I put my BHR ignition and msd wires and new plugs back in it and that didn't help either. </p>
<p>I know it probably doesn't matter but other modification on the car are an aluminum radiator and silicone hoses, a stage 2 clutch that came with the new tranny, and thats pretty much it besides the others already listed ( BHR, intake, exhaust). </p>
<p>I am at my wits end guys. I really want this fixed and any help will be much appreciated. I have been a long time forum member and other posts have been a huge help in expanding my ever growing knowledge. I just have a very unique situation that I haven't been able to take care of. I hope to hear from anyone soon and am more then happy to answer any questions I can. Thanks again everyone.</p>

 

Neutral safety switch.

 

Sorry, forgot to mention that. I checked and it ohmed out fine.

 

I was also assuming everyone would know by the stage 2 clutch comment, but just in case it is a 6 speed manual.

 

When you swapped the upper intake manifolds did you swap over your purge solenoid or use one already on the intake manifolds you tried?

 

Also, did you verify fuel pressure and does your engine consume oil at a normal rate?

 

Used that one that was attached to it. So it would have been two different ones. But just out of curiosity is the the one close to the throttle body?

 

Oh and is your air pump working correctly? That is what the P0410 code is for.

 

Yes the purge valve is right on the "catch can" built into the UIM. It can cause all sorts of issues with idling when malfunctioning. I suggest testing it properly.

 

Completely removed. So could this be caused by it still looking for it?

 

No if your air pump is gone it won't cause any issues unless you failed to cap the vacuum port on the air pump actuator. If that is not capped then there is your issue.

 

Its capped.

 

Okay, I would test the purge valve and if that is good then you may want to consider smoke testing your intake tract.

RX-8 Hymee Supercharger Install - Smoke Tester

 

Thanks for all the info 9k, I'm going to try and swap that purge valve or find a replacement first. I'm hoping that its not anything on the intake manifold seeing as how I just swapped all of those pieces and didn't have this problem before. If anyone else has any comments please feel free. I'll post up if I find the fix.

 

It sounds just like my car with the injectors wired wrong. With the recent engine replacement that would be my first guess. Was it ever working correctly with this engine?

Here is the wiring that I used origionaly posted by ROT8 The color on the exposed wires was really faded when I cut back the tape it was very clear that I had a green and blue wire corssed.

Fuel Rail 1 (two injectors)
Both leads for this fuel rail come off of the main harness together.
Front rotor injector wire color is light-green and red. (Front Primary 1)
Front injector Wire lead has White colored tape

Rear rotor injector wire color is light-green and black. (Rear Primary 1)
Rear injector Wire lead has Tan colored tape.

Fuel Rail 2 (four injectors)
The two center (the middle) injector wires come off the harness together and split.
Front side of the middle split has Yellow colored tape.
Rear side of the middle split has Green colored tape.
The two end (front and rear) injector wires come off the harness separately and have no colored tape.

The front injector wire is Green and Red. (Front Secondary)
The front rotor middle injector wire is Black and Blue. (Front Primary 2)
The rear rotor middle injector wire is White and Green. (Rear Primary 2)
The rear injector wire is Black and Blue. (Rear Secondary)

 

My only experience with idle surge was with the ESS. Cleaning it and brake stomp didn't fix it. Disconnecting the battery after for a few mins did. Sounds like been down that path though...

 

Well, I have a new symptom. Went on a 3 hour trip today and when I got almost there I noticed my high end rpm range was a little sluggish, but when I got to a few lights before my stop I noticed that it was idling completely fine like nothing was ever wrong. As if I wasn't puzzled enough already. P.S. After it sat for a few hours and cooled down, its still surging.

 

You need to check fuel pressure as well, verify it is in spec.