Okay-I had this all written up and the "server is too busy" got me.

I changed my plugs, this is what I found. I just bought the car in August and have been doing maintenance on my own. I should have done this sooner.



L2 L1 T2 T1



It looks like the plug face was burnt away.

 

Wow, good thing you decided to go ahead and change those out. I think I'll check mine this coming weekend now.

 

the trailing look alittle on the lean side as well. creamy brown is about what you would like to see, darker means your running rich, white is bad, meaning your running lean.

Tim Benton

 

yeah the 1st time i changed mine...they look just as bad. needless to say i believe it will be something i keep on top of.
brad

 

Group buy on plugs, anyone?

Anyways good pics, Mastacow. Generally tan but definitely worn and due for swap. Looks like a tight motor. How does she run now?

P.S. Keep those pics for future ref on the forum.

 

any idea how many miles you had on those plugs?

 

Looking from left to right, #3(Trailing?) and #4(Leading?) look like they are from the same rotor.
They are VERY white - you are running lean on that rotor my man and should look into it ASAP. Maybe it's just the lighting on the pix but I am concerned.......Pull your new ones again in a couple of hundred miles. You want dark cream color all around. Let me guess - you've had some hot start problems and bucking?

 

It seems most people with 7s don't change their plugs as often as they should. These pics should hopefully motivate some of us to take a look at our plugs. When the carbon is flaking off they have been in there too long. Anyway that one plug indicates some sort of problem. Normally the electrode (the pin in the center) gets worn down from having a flat top like a can to a rounded off top. The one plug pictured alone still has a flat top, which indicates that it might not have been firing. This could be caused by anything from the plug wire being lose to a bad coil.

As always my site has continued research on the various plugs available for the Rx-7 along with pics. Most recently I finished my testing on the HKS Iridium plugs.

 

I'm surprised that so many people have posted comments simply concluding that the condition of these spark plugs mean the plugs should be changed more frequently.

In my opinion, the deterioration shown on the one spark plug where it has partially burnt away, is an indication of a major tuning problem. I believe you are experiencing pre-ignition/detonation that is melting the plugs.

These plugs are telling you to take a very close look at your tuning and to make some changes.

 

No, no hot start problems...I was experiencing some stalling of the motor. The two plugs to the far right are the trailing plugs off both rotors...I guess I left that part out when I had to re-write the post.

From left-right, it was L2, L1, T2, T1. The crud on there is a tan color, I guess my color balance makes it look whiter than it was-maybe my camera's flash..

I haven't experienced any detonation-and as for it not firing....It idles smoothly, so I didn't suspect anything with that.

As for how many miles...no clue. I bought my car with no records from a porsche dealer last August.

It's running smoother now, but my idle is still hunting once in a while at stop signs....I'm having Jeff at Rotary Power change out my fuel filter within the week.

 

Keep us posted on those plugs and your tuning bec. those white ones def. indicate running lean.

 

If you idle is hunting at stop lights/signs with the clutch in...I would change out the clutch switch. It is at the top of the clutch pedal. It is depressed when the clutch is let out, and it extends if the clutch is pressed in.

They wear out...and cause a hunting idle when the clutch is depressed. Mine was bad...now my idle is rock solid.

I am changing my plugs this week...so I will see what mine look like.

Later,
Patrick

 

My buddy had a plugged cat for a while and everytime he started the car.....the plugs would foul out. It was really funny to see him get all pissed off over it.

 

Ouch, that L2 plug is REALLY a problem then - have your guy check it out thoroughly. That's going to be trouble with a capital T if you don't figure it out. New plug wires are cheap and certainly could be the problem or part of the problem. I personally like Jacobs. That's interesting wear on all the plugs - the leading electrodes usually wear much faster than the trailing.

 

Yeah-I'm going to be paying close attention to my L2 plug condition. I will be swapping out my plug wires either today or tomorrow. I have a set of 10mm Magnecors sitting in the box right now (the one under the plugs in the photo).

When I swap the wires, I'll pull the new plugs and take photos of them too.

You guys don't think it's just a result of neglected plug replacement schedule, do you? I didn't change the plugs when I bought the car, and I have no idea how long this set has been in there. The previous owner didn't leave any records and all I had was a clean carfax.

 

Being an old 2 stroke dirt track racer I really enjoyed your foray into the wonderfull world of der sparking plugs. I spent many sleepless nights as a youth reading tea leaves, spark plugs and other ephemeral stuff trying to figure out how to go faster. I can't believe someone would have the ***** to sell a single spark plug for $35.00 though! YIKES. I also had a good laugh at your expense when you said in your conclusions that you did not like the NGK, "that much is cretin". I may be an unlikeable dirty old man though, and that much is..... certain!

 

Darn spell check
cvs

 

I just changed my wires.

Man...you read all these write-ups, but they never quite convey the pain involved.

Knuckles are all busted up, I couldn't even get the throttle body off-was getting dark and hard to see.

I managed to unscrew the *THREE* bolts holding down the oil fill neck (the two obvious ones and the one hiding down below the horizontal part), just loose enough to slip the T1 coil's wire off.

The rest of the wires were relatively easy to pull-I just had to refer to a diagram to get the order right, since I pulled both leading wires to get to the second bolt on the oil fill neck.

I didn't take pics of the plugs-hands were all gummed up and was in a foul mood after wrestling with the coolant line to the TB...never did manage to get that thing off.

Oh well. I do agree with most people on the fit of the Magnecor wires...the boots don't instill a whole heap of confidence when they're seated at either end. I wiggled and shoved and poked the coil boots and the plug boots like crazy.

Started up fine. I'll pull the leading plugs in two weeks and take a look at them then. Just too tired and I still have about an hour's worth of work to do before I can head home.

 

Nope, there is definitely something going on with #2 to cause that kind of erosion, and it may be hard to track down. The first thing I would do is a compression check with the Mazda compression tester. (Only a really good rotary shop would have one of these) Basically it will rule out some problems. From there you may need to work backwards to coil output, injectors, etc. but something specific to that rotor and not a systemic problem. But, let's just hope it was a loose boot or a bad plug wire. Keep a very close eye on it and stay off the boost until you figure it out. Good luck and in your next life wish to born with tiny hands! (And don't forget to put anti-sieze on the plug threads and tighten them gently! - 1/4 turn after seating is more than enough - you'll feel them stop.)

 

This one def. looks like it wasn't getting a spark. The electrode is flat like it is when brand new just like one of the other guys pointed out. How did the wires look?

 

Any update?

 

I've been putting it off. I swapped wires the next day, and my idle has smoothened out. It still stalls once in a while, but for the most part, the problem seems to have disappeared. Im not experiencing, nor have ever experienced any detonation, and my engine revs smoothly. Idle is around 800 rpm, but hunts around once in a while after its warmed up.

I'll pull the L2 plug and take a pic over the weekend if I get a hole in my schedule to do so.

Oh, the wires. Wires were pretty rough looking. My engine bay isn't the cleanest to begin with, I'm still learning my way around in there, and I'm trying to clean whatever I can as I delve deeper into it. I've gotten as far as the coolant line to my TB-refused to budge, so I managed to pull the plug wire lines without removing the TB...just loosened a few things here and there to create enough clearance to get the old ones out and the new ones in.

I noticed my idle getting a bit smoother after I installed the 10mm Magnecors. The boots on the plugs don't instill a whole lot of confidence when they pop on...I had cuts all over my knuckles from trying to seat them.

 

Gee, hard to imagine a few busted knuckles from working on an FD3S........It will be interesting see that #2 plug again.

 

Okay, this is a bit worrisome.

Yanked the plug today before I headed into work.



The good news is, it looks like the electrode tip is rounding off. The edges are not as sharp as the old one was.

The part that worries me is that that circular pattern is forming again. I'm assuming that pattern is not normal.

Any input would be great. Thanks!

 

which plugs are those? platinum electrode or the regular kind?

Tim Benton