Notices
Series I Trouble Shooting This is the place to learn more about or discuss any issues you're having with your RX-8

Power loss/hard starting after spark plug replacement - What's wrong?

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 11-09-2010, 07:39 PM
  #1  
Registered User
Thread Starter
 
Cbriggz's Avatar
 
Join Date: Jan 2010
Location: Indiana
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Power loss/hard starting after spark plug replacement - What's wrong?

Hi, all
Recently on a spirited run down a long, straight strip of road, my car took a ****. It was a lot like the limp mode I hear described. Had to idle at 2.5k rpms to keep it from dying and had to have it in like 4th gear at 5k rpms to go 30 mph. When I got it home, the first thing I checked was the spark plugs. I found the insulator on one had cracked, so I assumed it wasn't sparking. I replaced all four (the cheaper ones from advanced auto) and my 8 was back to normal (or seemingly).
Except after that, I noticed that it seemed like I had less power. Also, whereas before it took a .5 seconds to crank, now it took more like 4 or 5. Sometimes I will crank it for 6 or 7 seconds then have to do it again because it won't start. Also, it seems like it is vibrating more than it used to; maybe I'm just being paranoid about that, but it seems that way. It also idles a few hundred rpm lower than it used to (now 800ish used to be 1000). I thought it was just me, but today I took it for another spirited run and whereas before I could chirp second and third (Please no flaming on why this isn't the best straight-away method, how I suck at shifting, etc.) now I can't even get a sound out of second. Also, before I was at around 40 at the beep on first, now its a little lower. Another thing I've noticed is that going from a stop, I have to give it more throttle to stop the launch then bog type of thing thats going on. I never had that problem before. Now it seems I have to almost spin my tires or take 2-3 seconds to let off the clutch so I don't bog down after the initial thrust.

Any ideas what could be wrong? My initial thought was that I detonated, which caused the spark plug to crack and now I somehow messed up the apex seal. I can still get it to high rpms without a problem, so I know I didn't blow it. I'm really just speculating, though. I'm no mechanic or rotary expert for that matter, so I don't really know much about this stuff. I have a full warranty from the dealer that I bought when I got the car. The problem is I'm a student, so I really can't afford to take it to the dealer, pay 200 bucks to have them look at it, then tell me 8 different things to change and pay for all of them before they finally fix what's really wrong. I mean, obviously I will if I have to, I would just prefer not to. Anybody have this happen to them? Any thoughts?

(BTW '04 24k miles)

Last edited by Cbriggz; 11-09-2010 at 07:44 PM.
Old 11-09-2010, 07:50 PM
  #2  
Registered
iTrader: (2)
 
Easy_E1's Avatar
 
Join Date: Sep 2005
Location: Bellevue WA
Posts: 7,675
Likes: 0
Received 5 Likes on 3 Posts
Take another look at the plugs. And while you have them out, throw them away and get NGK. (Assuming that the cheap ones from Advanced Auto are not NGK)
Recheck your plug wires and make sure they are in the correct order and pushed completely on the plug.

Do an ECU reset. Turn Ignition on and step on the brake pedal rapidly as many times as it takes for the "Oil Pressure" gauge to sweep left to right and back. Turn off the Ignition and then restart the car. Give it a bout three drive cycles to see if that helped.

If not clean your MAF sensor with CRC MAF Cleaner. Put a little lube around the o-ring when you reinstall it.

Take two aspirin and call me in the morning.

Oh and by the way,, you might just have a bad coil.
Old 11-09-2010, 08:18 PM
  #3  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
Originally Posted by easy_e1
recheck your plug wires and make sure they are in the correct order and pushed completely on the plug.

.
+1000
Old 11-09-2010, 08:21 PM
  #4  
Registered User
Thread Starter
 
Cbriggz's Avatar
 
Join Date: Jan 2010
Location: Indiana
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Plugs were NGK, and I'll check to make sure they're on right etc tomorrow (although I've changed spark plugs enough I don't think this is an issue, definitely worth checking tho) I'll do the reset tom too. I'll clean the MAF sensor too, but my problem with that theory (and bad coil) is that it was running fine before this whole debacle. Although I'm sure running half an hour in limp mode like that I was getting some crazy fuel/air mixture, so maybe that dirtied the sensor or something, or engine gremlins. Either way, I'll clean that out assuming I find no problems with the other stuff and see how it goes. Hopefully one of em will work. Any other ideas?

Late breaking news:
checked the spark plugs, all was good there, but I decided to take them all out and retighten them. When I took them out, found the base ring was pretty white despite me only recently changing the plugs. Decided it wasnt that big of a deal, so I reset the ECU and took it for a test drive. I went for three ~5 minute drives, shutting the car off each time. It seemed to gain power on each run and by the third, the back end was breaking loose a bit from first to second, which it wasnt before. I'm wondering if the misfiring for 30-40 minutes really did a number on the ECU and it still hadn't recovered from getting waaay to much fuel, so was givin me a lean mixture which accounted for the loss of power. It seems odd that it wouldnt recalibrate after these weeks of driving, so I'm not too hopeful yet, but at this point, I'll take whatever hope I can get. Either way, thanks for the ideas, Easy.

Last edited by Cbriggz; 11-09-2010 at 10:30 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jaco Greyling
New Member Forum
3
01-06-2019 08:39 AM
rotorocks
Series I Tech Garage
47
05-11-2016 03:23 PM
Obivious
New Member Forum
0
07-29-2015 05:57 PM
thedragonrotar
New Member Forum
1
07-22-2015 08:46 PM
Belalnabi
New Member Forum
9
07-17-2015 07:48 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Power loss/hard starting after spark plug replacement - What's wrong?



All times are GMT -5. The time now is 09:25 AM.