B and B

iTrader: (3)

92 Si, stock (sadly) Z6. Anywhere from 4k-7k rpm I experience intermittent misfire and the tach flails wildy. So far replaced plugs, fuel filter. Ignitor replaced last year with aftermarket. I've been reading some searchs, maybe someone can save me some time?

cstay

well if your tach is falling faster than the motor that it is ignition related because the tach reads ignition. dont quote me but u might be losing spark to all of your cylinders or just number one because i beleieve it reads #1 for RPM. how does the car idle?

B and B

iTrader: (3)

Tach bounces to higher rpm. I reset the ecu today and it seemed like it was idling a little rough afterward, but idle speed was <900 so maybe that's why it seemed rough. I'll be checking the ecu for code in a minute.

cstay

i would check your wires for high resistance because it could be sparking to the block. an or your distributor i would bring it to a shop before u just start replacing parts it will end up costing you less in the end.

triple_s1x

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cstay &raquo;</TD></TR><TR><TD CLASS="quote">i would check your wires for high resistance because it could be sparking to the block. an or your distributor i would bring it to a shop before u just start replacing parts it will end up costing you less in the end. </TD></TR></TABLE>


I would check the wiring on the dizzy, also the grounds. I dont think a faulty ignition wire would effect the tach at all. I personally had my number 1 wire get a tiny crack at the boot and it would just misfire, from basically arcing off the head.

_Cyclone_

I had 2 loose wire connections on the terminals of my aftermarket ICM. Mine did the EXACT same thing yours is doing now. It'll get worse if you don't fix it, then you'll melt your converter. (like I did... )

What you should do before anything is take off your distributor cap and rotor (DON'T STRIP THE SCREW.) Pull each plug off the ICM one by one as to not get them confused. Use a pair of needle nose pliars and give each connector a little squeeze so they can clamp firmly on the terminals on the ICM. This won't take you long, and it'll probably fix your problem. Let us all know how this works out.

B and B

iTrader: (3)

I'll do it tomorrow, gotta get up in 5 hours, thanks for the hint, dude.
ECU has no stored trouble codes.

B and B

iTrader: (3)

You were correct!!! Thanks alot, my friend. The lower rear terminal was only contacting because the little plastic boot was capping the male spade of the module, so the spade was touching the back of the female connector inside but not attached. I can't believe I installed it like that, or that it ran well for a year. Revving happily again!!! I thought I'd drop a valve testing, it felt so good.

_Cyclone_

Now, if it matters enough to you, you should pull your converter and visually check it. Mine had a hole in the catalyst about the diameter of a pencil melted from one end to the other, and the rest the catalyst in the middle was all broken up. This was caused by an excess of fuel being dumped into the converter when it got worse on me before I fixed it. When it was running good again, it lit up like a heat lamp...