I just got back from Tuning Technologies to dyno the car after installing
a new optispark. I don't have the dyno graphs yet, but they look pretty
much the same as the one in my sig. It's time to change the plugs, check
out the coil, and give it another go. The problem does not appear to be the
optispark. The Rapidfire #14s may be the problem so TR-55s are going in
as a replacement.

The best numbers today were a slight increase over the last pulls. Had
323 rwhp and 331 rwtq on the last pull, and 334 rwtq was the best torque
on the second pull. An interesting note is that the A/F was about a solid
point lower across the graph for all three pulls, even though the program
is the same and no other mods besides the opti were made.

If anyone has any ideas please post them.

 

I was having similar problems:

http://www.jonaadland.com/NewPics3/Dyno2.JPG

Replaced the coil, ICM and PCM:

http://www.jonaadland.com/NewPics3/Baseline.JPG

I don't know which of the three fixed it.

 

Thanks Jon A,

I'm not sure how the PCM would cause that, but you never know. I'll have
to look into the ICM, and will probably replace the coil just to eliminate it
as a possibility.

 

I'm not sure either, but the Helms lists it as a last resort for lots of different ignition problems. That's not why I replaced it though, I was switching to OBDI anyway. The coil and ICM are relatively cheap and easy to replace, I'd definately do that first.

 

I updated my sig with the dyno graph from the last pull today. It may be
worth the experiment to replace the coil since it's easily done. I don't need
the dyno to feel the car lay down. The SOTP meter works just fine for that.

Also, the A/F ratio on the three pulls today was about a half point lower than
the last pull before the optispark replacement. I'm not sure what's going on
there.

 

The AFR thing could just be their O2 begining to go or maybe it was a new one, at least ask them about those possibilities.

 

Same thing I was thinking. I wouldn't be too worried about it.

Mike: get those crappy plugs out of there. For whatever reason, my car ate those things up and I ended up getting about 1k miles out of them before they fouled so bad it was pathetic. Also, send your new graphs to Jeff for comment and possible tune adjustment.

 

It doesn't look like quite like ignition to me. Whatever it is its pretty funky.

Have the guys give you a dynojet file then look at it with the correction set at 5 (the standard most dynos use).

 

I'll definately change the plugs, and I already sent Jeff the files.

Here is the graph with a smoothing of 5:

Dyno Graph

 

how does it feel on the street?

 

Damn that graph is choppy. Does it feel as bad as it looks??

My guess is you lost a cylindar or 2 or 3.

 

It just feels like a minor lay down at around 5,200 then picks up and is
even more minor up to 6,000. Most people riding in the car would not
even notice it. There is nothing in the exhaust note that indicates what
is in the graph. It's all a feel thing. The engine does not miss a beat
based on sound. I hate the Eenie Meenie Miny Moe approach to auto
repair but this is one of those that's hard to nail down.

On the 2nd pull last week the graph was close to normal and then it was
jag central after that. It should not be knock, float, or the opti, everything
else is a possibility.

 

I've seen auto cars do something simular to that.. When they try to centrifically lock the next clutch pack or somethign simular to that.

To me it looks like it may be retard, which would explain why the car got richer.. let us know when you figure it out