stefuel

Sometimes I get misdirected to threads that for one reason or another catch my eye. In doing a search about knock sensors I stumbled upon a thread about why some Z's run like a bag-o-$**** if they run anything but OEM plugs. My first thought is someone is smoking something....BUT I started thinking, what could actually cause all the weird crap that some claim to experience? Surely there is sufficient spark to light the air/fuel mixture so that most likely is not the issue. Then I started thinking about my early days as a auto mechanic (before many of you were born)
EMI. It was really never a problem in the 60's...or was it. C2 Corvettes suffered radio problems with the distributor right up against a fiberglass firewall and the radio only inches away. There was no resistor plugs or resistor wires back then so good ole Yankee thinking GM devised a metal shield to cover all the high voltage stuff. Problem solved. Later came better plugs and wires. OK, back to the C6Z. How many things are digitally controlled in close proximity to the ignition system on the LS7 and what has been the major complaints when not running OEM plugs? Weirdo thing number 1 that I have read about "My alternator only works if I use OEM plugs" How many times has this been said and those that said it have been ridiculed? A digital micro circuit is in charge of controlling the regulator and output of the alternator. Could EMI pulses wreak havoc with that micro circuit. If the EMI pulse is strong enough, you bet your a$$ it could. Complaint number 2 "My car surges on aftermarket plugs. Put OEM back in and it runs fine". How do you adjust the throttle cable in a C6 Vette? Oh, that right. silly me. It's fly by wire. Another micro processor controlled servo motor. Can EMI effect that? Probably more then it effects the alternator. What I don't understand is why some more then others. It has me wondering if there's more then plastic in those red engine covers. Something that blocks or redirects EMI away from the throttle body and alternator. Do those with covers on suffer the problem less then those that run with covers off??? OK time for a beer. Have a nice weekend.

MTPZ06

lbzraptor

My car runs just fine with the covers off. Took them off a week after I got it. If any thing I think it is cooler in the engine bay with the covers off.

rio95

I've run TR6 plugs and no covers for 15k miles and I don't think they've ever been a problem for me. I have gotten low voltage message in stop and go traffic when really hot out but I think that's more of an alternator issue that seems somewhat common. Thinking about going with an aftermarket unit.

rjacobs

I run regular copper TR6 plugs as well, no covers, never had an issue.

meanjoe

ratomicZ06

The covers are plastic, dress up, but EMI can be very intrusive, take my boat for example. (Great timing OP!)

11 years since new and none of the marine mechanics nor myself could figure out why one of the engines would just.... "skip a heartbeat" for lack of any other way to explain it. The electronic tach would dive down, then back up from a ever so slight miss. Most of the time I would never even feel, nor hear the miss, just see it in the gauges. It didnt matter if engines were hot, cold, any rpm, air temp, load, etc...... it would just happen randomly every few minutes or so, or maybe 30 minutes later, just a split second miss. Drove me nuts because the synchronizer display would show a disparity and sometimes I'd hear a quick audible oil pressure alarm.

Changed plugs and wires, no change. Looked at lead dress of plug wires at that time and re-routed wires, best i could and still no change in the cadence of the random miss. So, been going on for 11 years, off and on, got used to it.

This year changed out the manifolds and that gave me the view I'd never seen before..... wires for the fuel pump in the fuel cooler were smashed down under a hose in close proximity to a plug wire. I dressed them up and away and not one hint of it happening again!!! Its been 2 outings, all good. LEAD DRESS from Mercruiser all these years!!! Yes, EMI.



(Note: Paragraphs.... )

Mordeth

I run TR6IX plugs, Firecore 50 wires with Pro-mod boots and no covers. Car is a track car. No issues, problems or drama.

sillycon

Tr6ix here as well. There are definite EMI issues with these vehicles; a buddy of mine and I were working on my c6z a few weeks back and he reinstalled the alternator battery cable. He tucked it in quite nicely down by the #1 coil pack. A few days later, i start getting ramdom "service charging system" messages on the DIC. Finally having enough of this (and not having had the issue prior to the that wire placement) I loosened the B terminal and routed the wire higher away from the #1 coil. "Magically" the SCS messages stopped popping up! Ive seen some bizarre EMI issues before, but nothing as sensitive as that.