Loss of power at high RPMS, extremely poor fuel economy, no other symptoms
 

Car: 2004 RX8, MT 68K, Stock

Symptom: Suddenly last night when driving up the hill to my house, I noticed the car seemed to not have as much power, but I wasn't on it, so I thought nothing of it. This morning on my way to work it's incredibly obvious that anything above 4k, the car just feels unresponsive and flat and lacking that sudden surge in power above 7k. I've driven the vehicle ~50 miles since this began and have no MIL or stored DTCs. I, honest to God, could physically watch the fuel needle going down on my drive to work this morning. There are no other symptoms accompanying it. Starts fine. Idles fine. No excessive smoke/steam from exhaust. No strange smells. Low end power is still the same. But there is no top end power. I've not had any time this morning to check it out, but I have a feeling that the culprit is the SSV. Within the past 2,000 miles I've installed the following- NGK plugs, NGK wires (ZE81), 4 Ignition coils (BWD), Oil & filter, Coolant, Transmission fluid, Differential fluid, Brake fluid, Cabin microfilters, Front pads and rotors all done as maintenance with the exception of the brakes. I'm an ASE certified technician (A1, A4, A5, A8, C1, P2) and manage an independent shop, so I have the knowledge to test practically any component and have a fully equipped shop at my disposal. A couple of days ago, I removed my converter to inspect it and found that it was clean and clear and looked to have been replaced relatively recently, so that's not the problem. I'll hook up the Solus and see if I can get some live data recordings on my MAF and O2s, but would like if someone could point me in a specific direction to start with. Again, I'm thinking SSV, but am absolutely new to the Renesis (and all rotaries for that matter). Any and all help is appreciated.

Hard Starting?
 

I know you said it has no problems starting, but does that mean cold starts or warms starts as well? I had those symptoms plus problems hard starting and it was the low compression issue common among these cars.

No issues either cold (this morning) or hot start (after driving 25 miles) to work. And again after driving another 10 miles to my other shop, parked for about 20 minutes, then restarted to drive back to my shop.

It's been sitting for about an hour and a half and just went out to start it and no issue. No extended crank. No misfire on start up. No smoke. Nothing.

Good!
 

Well thats a good sign I think, I don't know what the problem is then though :/

Yeah, I operated the SSV manually and it moves with little to no resistance. The switching valve also operates as designed, so I've retracted my theory as to the SSV being the culprit. I would assume engine if there were other symptoms accompanying it, but there are none. I think I'll do a compression check just to do one so I have an idea as to the health of the engine.

Someone recently (couple months back) had a similar problem where when one of the control solenoids got hot, it then would fail to open the valve it controlled.

I can't remember if it was the SSV control solenoid 100%, but I believe that was the one responsible in the thread.

Try swapping your SSV solenoid for one of the other ones, and see if the problem goes away.

BC.

Will do. Another thing that I realized is that since owning the car, the temperatures have been cold here until yesterday when we got up to almost 70 and today when we got up over 70. The solenoids are identical to the VICS/VTCS solenoids on an FS motor and a million other Mazdas and I've got 5-10 of them, so I'll switch one out maybe.

So, I was just spending a few minutes here and there throughout the day and looked for residual oil in the intake tube and/or throttle body and there was none, and from searching it seems that is a common symptom associated with an SSV problem. While looking, I removed my MAF and it was filthy. I've cleaned many, many MAFs but I've never seen one this dirty. I cleaned and reinstalled and the car seems to be doing much better. Fuel economy is back to normal based on the amount of miles I've driven in the past few hours this evening. Though it still doesn't feel completely 100% intermittently, but I think I'm just paying too much attention at this point and letting my imagination gain hold of my thought process. I'll drive for a few days and keep an eye on everything.

Many put catch cans on the crankcase vent line leading back to the air intake tube. This should reduce fouling of the MAF.

So the problem is still there. I'm going to get about 210 miles out of this tank whereas I've been getting ~250 per tank. I've identifed the two areas in the RPM range where it happens- 6,000-6,500RPM and 7,500-8,000rpm. In those two RPM ranges, it feels like you hit a wall. Between 6,500 and 7,500 it comes alive again, only to hit another wall. Still, there are no other symptoms accompanying these. I beginning to think that I may have a prematurely failed ignition component. The plugs/coils/wires were installed almost immediately before this happened. I'm talking ~100 miles at most. The Borg-Warner coils are the component I actually suspect is bad. I have three ignition coils that were removed that looked to be okay, so I believe I'll reinstall them and see if that changes anything.

I shut my shop down early tonight because we didn't have any cars to complete, so I brought the car in and sprayed Windex around the ignition cables, spark plugs, coils to help identify any possible arching and found none. I did, however, find that my front rotor, leading ignition wire was only held on by the boot over the ceramic. I've properly installed the ignition wire and will drive home here in a bit. I'll be very, very glad if this was the problem. It completely makes sense considering how soon this happened AFTER the wire/plug/coil installation.

I really, really hate when somone starts a thread on a forum asking for advice/recommendations when it comes to trouble shooting a problem and NEVER come back to let people know if it was ever fixed and if so, what corrected the issue, so...

The loose ignition wire was the culprit. It was obvious as soon as I left my shop and drove home. Everything is back to normal! Glad to be getting 17mpg again! LOL

On a side note, I also got gas the following morning and did not premix just for the hell of it and the car actually seems to like that better. Maybe I was using too much premix, but not based on the 'Premix Thread', because I only add 6oz. of premix to a full tank- 13-14 gallons on a fill-up.

FWIW, I've never notice any problems premixing at that ratio, no noticed any improvement when I skip it for a tank. And my mpg's are pretty good (for an RX).

So, the power loss came back, and I checked everything else again including, and first, the ignition wires and all seems to be okay.

The power loss started today on my way to work and the car sat all day at my shop. After I started it to go home, it smoked a bit more than normal and I checked the exhaust for any evidence that it might be coolant and/or oil, but it seemed to be nothing but raw, unburned fuel. Today I think the high temperature was 30 degrees. I drive it about 18 miles, park it for 10 minutes, drive another 5-6 miles and still seems to be lacking power. I get on the highway and open it wide open because a Jeep wants to ride my ass. All the sudden at ~7,500 it opens up like normal and just happen to look in my rearview mirror and see a huge plume of smoke and after that ALL the power is back. Let the car sit for another 10-15 minutes, go drive the car and it's fine.

Any ideas? HELP!?!


Okay, well, I stopped premixing after doing 7 tanks of fuel with/without 6oz/13-14gal.(basically empty on fill ups) and my mileage was as follows.
I keep all my fuel receipts, so I'll check them and see exactly how many gallons of fuel I got at each fill-up when I get a chance.

Tank 1- No premix, 229 miles
Tank 2- 6oz premix, 208 miles
Tank 3- No premix, 236 miles
Tank 4- 6oz premix, 209 miles
Tank 5- No premix, 227 miles (which surpised me because I did a lot of high rpm, aggressive driving for 20+ miles)
Tank 6- 6oz premix, 193 miles!!!
Tank 7- No premix, 237 miles.

Obviously there is something up when going with premix. Could it be the brand I'm using perhaps?

I meticulously measure outl 6oz and don't just "pour some in and 'guesstimate' the amount" or anything of that nature. I probably look very strange to those other people at the gas pumps.

Update:
So, the power loss is very intermittent and noticed I've gotten a slight rattle on initial throttle. I pulled up to the side of my shop, gave the accelerator a few kick taps and could hear the unmistakable catalytic converter rattle and accompanying it now is a catalyst death code. Put it in the air, hit on the converter housing, and it rattled to all hell even back to the resonator indicating material from the converter has reached it. I ordered my AP midpipe a few days ago, so that's going to work out well.

I believe the converter has been the culprit this entire time.

THanks for the update

I give updates because I hate when a member logs into a forum, makes a thread asking for a solution to a problem, is given a few different things to try, then is never heard from again. If someone is experiencing the same problems, that information is very useful to them.

? I wasn't flaming

I totally agree with you so I like to Thank the OP for updates

Thanks ... no for really really

Any Updates on this? Seems like I have the exact same issue...I have tried many things, but not sure what else to check.

BTW I have a 2009 RX8 R3.

Hi Preferio! What happened in the end? I have the same problem last 2 weeks. All started after oil change. I drive RX8'04 highpower mt.

No check engine light and like you say loss of power and feels like you hit something when rpm comes to 5000, 6000, 7000.

It ended up being the converter. It started coming apart and restricted the exhaust flow. I replaced it with an Agency Power midpipe and it took care of the issue.

Actually, the converter came apart and at WOT, while I was hitting the proverbial brick wall, suddenly a huge plume of soot/smoke/etc. shot out of the exhaust and all power came back. After that, it rattled like all hell, so I removed the cat and dumped out what was left in the midpipe, but still had pieces in the aft-cat portion of the exhaust.