Dartanian

I got my car dynoed today and I guess there were problems with the ignition pickup, so there are big holes in my graph around vtec engagement range. The guy doing the dyno said that my ICM was on its way out and giving it problems. The car doesn't feel like it is having problems, so I was unaware of this until today. What is the problem here? Spark plugs, wires, distributor cap/rotor, or ICM?

ImportMotorSpec

I have seen that often with cars with MSD ignitions.

Don't know if that is your case, but very common. Especially on dynojet's.

Dartanian

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ImportMotorSpec &raquo;</TD></TR><TR><TD CLASS="quote">I have seen that often with cars with MSD ignitions.

Don't know if that is your case, but very common. Especially on dynojet's.</TD></TR></TABLE>

It was on a dynojet, but I am running stock ignition.

Is it something to be concerned about since it is my daily driver, or does it only really matter when it gets dynoed?

B18C1CYA

spark blow out ????

Dartanian

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C1CYA &raquo;</TD></TR><TR><TD CLASS="quote">spark blow out ????</TD></TR></TABLE>

That is what I was thinking, but wouldn't it be blown out a little farther up in the powerband? I am running a .035" gap, so maybe I should step down to .030"?

Like I said, I can't notice this problem when just driving it around because it feels really smooth and I know what a misfire from incorrect plug gap feels like.

BIGDADDY-R

try changing out the ICM some times they send a bad signal and you have random missfire

evilone

very good chance it is the pickups on the dynojet, if you were blowing out the spark there would be a dip in power, see if the dyno shop can give you a graph based on wheel speed rather than rpm.

RTW DC2R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prostock &raquo;</TD></TR><TR><TD CLASS="quote">very good chance it is the pickups on the dynojet, if you were blowing out the spark there would be a dip in power, see if the dyno shop can give you a graph based on wheel speed rather than rpm. </TD></TR></TABLE>

this is the first thing I thought of.

Toda Party

iTrader: (2)

it happened to alot of cars we did on a local dyno jet...

i think its just the pickup, its not used to the vtecnique xover, i had a couple cars that had missing mid-range values..

shrug.

vadersi

if you are running thick plug wires the pick up will not get a good signal.

vadersi

next time use the tach signal blue wire and have the operater chang e the dynojet to i believe 180 degree firing

Dartanian

Yeah, my car was the only one that had ignition pick up problems and he told me it was the ICM. I will see if I can change that out along with the spark plug wires and a new cap and rotor and get it redynoed a little later. Thanks for the help guys.

onefstek

it defenetlly looks like spark blow out. what is you spark plug gap? I seen an imporvement by droping the plug gap down into the .020's.

Dartanian

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by onefstek &raquo;</TD></TR><TR><TD CLASS="quote">it defenetlly looks like spark blow out. what is you spark plug gap? I seen an imporvement by droping the plug gap down into the .020's. </TD></TR></TABLE>

It is .035". I will try regapping them.

The thing is that I can tell when the spark is being blown out because it will misfire and hesitate under boost, but it wasn't doing that...so I assumed the gap was just fine.

USDM 4G VTEC

thats not spark blow out
dang people, stop posting stupid ****

if spark blowout was a concern here, it wont do that in the dyno
the problem they encounter is that the dynojet pickup is not receiving a full and steady signal from the vehicle thru the pickup clamp on the spark plug wire

if the spark gets blown is due to high cylinder pressures and or big gap, means the electric signal will go thru the cable to the spark plug , but wont be able to jump into from the electrode to the ground due to the phenomena

my friend who has a Dynojet, sees this problem often and its usually, dirty or bad grounds, bad igniters, and or a bad or worn out cable, cables too thick and or aftermarket ignitions

also make sure that the dynojet ground cable is on a good spot, and its not moving around or vibrating while the engine is being dynoed

Dartanian

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDM 4G VTEC &raquo;</TD></TR><TR><TD CLASS="quote">thats not spark blow out
dang people, stop posting stupid ****

if spark blowout was a concern here, it wont do that in the dyno
the problem they encounter is that the dynojet pickup is not receiving a full and steady signal from the vehicle thru the pickup clamp on the spark plug wire

if the spark gets blown is due to high cylinder pressures and or big gap, means the electric signal will go thru the cable to the spark plug , but wont be able to jump into from the electrode to the ground due to the phenomena

my friend who has a Dynojet, sees this problem often and its usually, dirty or bad grounds, bad igniters, and or a bad or worn out cable, cables too thick and or aftermarket ignitions

also make sure that the dynojet ground cable is on a good spot, and its not moving around or vibrating while the engine is being dynoed</TD></TR></TABLE>

Thanks for clearing that up for me.

Everything from the wires to the distributor needs to be replaced anyway, so I will get that taken care of and hopefully it won't show up again when I get it dynoed. I am going to not blame it on the dynojet equipment since no one else had that problem and just fix my problems.