FF2Skip

*** I locked the thread in Technical. ***

I'm currently running a a fairly modified, supercharged S2000. Went to get on the freeway yesterday morning after meeting up with some car folks that were headed to a show. I couldn't go, but wanted to meet up and decided to roll on the freeway for a few miles.

Went to get on it and it sounded like I hit the rev-limiter at 7k. No, the car was more than warm reading 88* C. Didn't think too much about it as the air was already very warm and muggy. Went home and parked the car. The Mrs. wanted a ride that night since the hardtop had been removed. We drove around a few back roads at a very leisurely pace. Finally, I asked her if she wanted to see how fast the new setup was. She said, "Sure." We headed to the freeway where I went to get on it. Sputter.

I told her something wasn't right and we casually drove back to the house. I just pulled the plugs to check them and sure enough, I broke the #1 cylinder electrode off. Are there any precautions I should take prior to installing another set of plugs and firing her up?

Thanks,
Skip

Billman250

Holy crap....Is that a clean break or did it etch or melt away?

I'd go in with a hanger with something sticky on the end like tape or gum and see if you can fish anything out.

If you are lucky, the piece will be sitting in the front of the cat. converter, if you still have one.

Big question here is why did it break. I'm sure you gapped them, do you remember if one of the plugs had a real small gap when new, and you had to open it up?

John_Z

Could be running lean, detonation, or just a bad plug? Have you ever checked your A/F?

FF2Skip

Bill, it appears to be a clean break. I used a magnetic, antennae-looking pickup to fish for the other piece. No luck.

So then I decided to do a compression check. First go-round yielded 156, 165, 190, 225- #1-4 respectively. No milkiness to the oil, thereby possibly ruling out the head gasket. I decided to try the compression test again starting at #4 and working my way back the #1. #4 was 225 again while #3 was 195. #2 read 150, but the battery was toast at that point. Too many shops(tuning and body) have run down the battery.

This calendar year I did a compression test. All cylinders read over 215 if I remember correctly using the same gauge. Both times were with the engine having sat over night.

Concern is growing.

Billman250

Electrode is non-magnetic

ADAM_ROB_UK

i cant offer anyhelp as im not good in this area, but what are the compression # supposed to be on all 4 cylinders ??

also would it be worth taking the head off to see if it dropped in to the cylinder ?

good luck and hope the car is ok

FF2Skip

No cat.

Yes, I had to gap them. They are NGK 7173's and come at .030". I gapped them to .033". Funny thing is, when I pulled them, they had a silver/aluminum substance similiar in consistency to anti-seize on the threads. I have never added anything to the threads.

I'm thinking the tuning shop pulled the plugs to check them and reinstalled them. The gaps on the 3 readable plugs were .030", .035", and .034". The plugs also got lighter as they progressed to the #4 plug. I'm thinking this was in compensation for the #1 not being able to burn all its fuel. The wideband read a certain condition(rich) and the EMS adjusted accordingly. I run in closed loop when under normal(low-load) conditions. ...

FF2Skip

Okay. I placed the tip on the electrode while still attached to the rest of the plug and it stuck nicely. Obviously then, it is at least conductive of such forces.


Note: I'm trying to laugh to keep from crying!

Billman250

The magnetism is coming from the thread base.

The part that went into the cyl cannot be fished with a magnet (at least the OEM plug)

Break the rest of the electrode off and try it

FF2Skip

I'll try double-sided tape on a hanger, but I fear the compression numbers are telling me a horror story.