I have a 2004 A/T Grand Touring Rx8 with 98xxx miles. I bought my car back in march of '13. Ever since I bought the car ive never really had any low end torque (which i expected) and I had a decent power band from 3500rpms to about 6rpms. Occasionally my car will run flawlessly and the power band goes from 3500rpms to 7500rpms flawlessly. It feels FAST when it runs like that, but the majority of the time it doesnt.

SO....

Over the summer I gutted out the cat and put new plugs, wires, and coils. Car was running pretty solid for a while.

Lately, my cars acceleration really dies out around 6,000rpms and the rpm gauge really struggles to make it to 7rpms, and sounds like its gasping for air and throws misfiring codes (back fuel/air ratio??) hence the SSV issue.

When I bought the car in March the check engine light was on because the dealer said that they replaced the blown engine with a used one. Well I used carfax the other day (I should of done it before buying the car) and although there was no report of the dealership every replacing the engine, it was reported that the engine was replaced back in '07 with only 40k miles on it. However, the dealer did report that the car failed emissions report the day before I bought the car (3/14/1994), so why wouldnt the dealership also report the engine was changed? Because it probably wasnt changed out and they had a reason to charge me an extra $1500 because it had a "new, used engine". Does that mean my engine has 98,xxx - 40,xxx miles = ~58,xxx miles on it? But my car has "seen" 98,xxx miles? It seems like at this time in '07, the engine must of been pulled and upgraded to the newer series/generation.

Anyways, back to the real problem at hand, the SSV. So the actuating arm (that thing that you can manually move with your fingers), is easily movable and it has a full range of motion, so my SSV isn't gummed up. BUT, it works sometimes and sometimes it doesnt, but when it DOESNT work, I can still move the actuating arm by hand. Because it doesn't ALWAYS work, it seems to be an electrical problem. And I do recall my CEL came on and read something along the lines of bank "x" circuit high (or maybe it was low). Ive read that this could indicated an electrical problem. If the problem is electrical, where do I go from here (aka what do I replace?)

Before anyone says anything about compression, my car runs fine SOMETIMES, so I doubt a compression problem would come and go, like my problems has been. Just to be safe, im going to test the vacuum line today that goes into the SSV.


Ive been doing a lot of research about this and Im hoping its electrical!

Thanks!

 

intermittent problems are usually caused by the solenoids on the back of the UIM which have an average lifespan of about 80k miles before they become problematic.

if the engine runs fine when lukewarm but falls flat when fully warm or better in winter versus summer this is a better indication of the above.

 

Perfect explanation! So how do i replace just solenoid?

 

It's not that hard, you'll need to remove the UIM (Upper Intake Manifold)

I suspect however by the fact that you even had to ask means it's likely a job you're not capable of doing yourself.

But none-the-less here is the Series 1 work shop manual.
You'll find directions inside.

It's best viewed with IE .. and don't use anything past IE7 .. you can hit F12 and switch to an earlier browser version of IE to view the content ... in this case select browser version 7
M A Z D A

 

I actually consider myself to be mechanically inclined. Im simple when it comes to vocab, but the actual mechanic part im good at, or so I tell myself that.

Regardless, thanks for the link, Ill be sure to use it and try it out!

 

You are welcome.

Let me know if you have browser issues ... it can be a PITA to make that workshop manual resolve correctly in the browser