Spark Plug Wire Routing

[equalizer]

I'm just curious as to how other people route their aftermarket 8mm spark plug wires on their 3.4L. I've been trying to fix a stubborn intermittent "missfire" style feeling ever since i've had the car. I've posed several times on here about this. just thinking maybe after installing new wires i just fried those too.... :-D I never know. I'll post pictures of how mine are running now if anyone wants to see.

If your curious as to what i've done to try and alleviate the problem, here's my long list.... :-D

Spark Plugs - AcDelco RapidFire's @.045 gap
Accell 8mm Plug wires, Spiral Wound Magnetic Suppression wires

New Coil Packs
New ICM
New Fuel Filter
Disconneced the EGR hose going into the intake manifold.
Fuel Pressure, and Regulator are fine and working properly.
I've ran several different bottles of fuel injector cleaner, including almost 1/2 bottle of Seafoam through the gastank.

I miss almost all the way through the driving range, and its not necessarily a hard miss. Sometimes it just kinda gives a little feeling of a miss. Although at higher RPM's you can really feel the jolt. I'm going to try and hook it up to a comptuer to read the realtime codes, but I have to wait for The guys who make EFI live to get back because of a few questions i have for them. Thanks for any help.


-- Mike

[FunkZ]

I reused the stock wireloom anywhere the wires come in contact with each other or anything metal. Pretty much followed the stock wiring path, although my Taylor SpiroPro wires wouldn't fit in the stock plastic wire clips.

If spark is jumping through the wires you can hear it with the hood up. If you look at night you can also see it.

[strange_trp]

why disconnect the EGR? in both 6bangers used in the f-body, the EGR operation is essential to reducing detonation (spark knock.) your miss may be due to incorrect fuel delivery because the pcm thinks its giving EGR to the intake when really its not (ie there is more O2 in the intake charge than the pcm expects) this would certainly throw a code on an obd-ii vehicle but maybe not the 3.4's. reconnect that bad boy. the pcm will cut egr altogether at WOT anyway.

also on the 3.4 unless you have a tech2 you probably are not going to do a power balance test with any generic scan tool and the codes won't show you misfire data for an obd-i system. misfire monitor did not start until mid-prod 95 models with the 16-pin dlc. i'd do power balance the old fashioned way and kill fuel or plugs one at a time to watch rpm drop. this may isolate a cylinder. really the best way if you don't have a scope with inductive pickup to see firing kv's. also check out your O2 readings compared to ST and LT fuel trim.

good luck

[ November 14, 2003: Message edited by: strange_trp ]</p>

[equalizer]

Just FYI, the Miss was happening way before i disconencted the EGR. I just disconnected that recently, and havent noticed any adverse performance

[strange_trp]

do you feel it worse under a load or just at high rpm's (like is it worse high rpm's climbing a hill or going down a hill. also if you go up a hill without downshifting is it worse then?)

ign miss is worse under load, almost always.

y u disconnect egr anyway? pcm cuts it off at WOT regardless...

hummm also, is .045 right for the gap on the 3.4? i was thinking that all waste spark gm used .60 gap. i know the obdII 3400's do. double check and increase the gap if necessary.

[ November 17, 2003: Message edited by: strange_trp ]</p>

[FunkZ]

.045 is what is recommended for the 3.4

At .060 the car runs like crap.

[MustangEater8251]

I drove his car once, and I felt the miss,its very slight, barely noticeable but I felt it.


As for the plug wires, you going to be at Sonics tommorrow? I'll see how you are running them.

My car ran fine, no missing with generic Accel 8mm plugs for a small block, from autozone, I just routed them under the hood and used the wire looms they gave.


Your plugs are relatively new right?

Also did you check your coils with an multimeter to see if they are within specs? (I just found mine, and I know scott has one) (*edit, noticed you changed them, Did you get used ones?)

*edit you replaced the ICM

[ November 17, 2003: Message edited by: MustangEater8251 ]</p>

[strange_trp]

cant exactly trust a static resistance test of coils. i've seen quite a few test fine but crap out when under driving conditions. if its a slight miss that does not get worse under a load my first thought would maybe be fuel/ emissions control problem.
ignition misfires generally are much worse under a load and usually you don't hear them described as "slight."
if you have access to inductive pickup, check peak firing kv of each coil winding with the engine at idle and when throttle is snapped. this will let you know if you're dealing with one cylinder or a random miss...
ignition sys would not really be my first guess, based on my understanding of the symptoms...