seen4ever

For the past month or longer, I've had a random breakup/misfire. First started when my MSD distributor had the pin backout. Managed to fix the MSD distributor, put OEM honda pin and key on it. Went to the dyno to attempt to tune out the top end, and around 8500ish, the car would mis-fire stop making any power.

I came home, did a compression/leakdown to validate the engine was healthly (180 on all four, 7% leakdown).

Bought a cheap new OEM distributor (turned out to be distributor King) and car misfired at 7k. Went back to a known good OEM distributor, put on a new MSD cap/rotor, new plug wires, new plugs gapped to .024. Same mis-fire around 7400ish.

I've even switched between the Hondata Rom4 to the old Romeditor, just to make sure there wasn't any random hondata bugs.

Setup:
ERL superdeck 2 b16
CP 9:1/Manley rods
Built head
CTR cams
gt3567r
direct port nitrous
FR topmount
4in downpipe/4in exhaust
Before MSD Distributor with coil/ignitor, MSD wires
Now OEM distributor, MSD cap with external coil, NGK wires
Hondata s200

Basicly, I'm stumped on where to go. The only thing I can think is maybe my battery voltage is a bit low, seeing how its at 12.9v at WOT with headlights on. The charging system is all new with a red top battery.

Only thing else I can thing of is some ICM wiring from the ECU to the distributor, maybe picking up some interference or something.

Any help is welcomed.

mrbsponge

what plugs and what power level are we talking about

seen4ever

started with the MSD distributor with the 8s at .024, put in a new set gapped to .020.

swapped over the stock distributors, with the 8s and last night i put in a set of 9s gapped to .022.

NGK plugs of course.

at the track and dyno, I would have to boost up to 25psi, no spray. as it misfired i backed down boost all the way to 10psi, trying to get a clean pass.

The dyno pull is 14psi, so whatever that translates to on a 3567r...in and around 400ish. Not alot of power, so this stuff should be going.

I'm just completely stumped, as 3 distributors, no change, it has to be something outside of the distributor, but really its a misfire, or spark related...

A/Fs are holding in the mid 11s to right around 12ish.

mrbsponge

might wanna go to a set of NGK 7s, they are more than likely the plug you need to run, 8s and 9s are way too cold for the 400hp range, i am in the 6xx hp range and am running 8s but i think i need 9s

FaceTuned

iTrader: (4)

at what deg*in timing does this breakup accure?
and have you tried running a tighter gap in the plug?

JrCRXHF

I talked to a guy in Michigan at a drift even about 2 weeks ago with the same problem.

I had a problem with mine that i chased for a while and then felt really dumb when i found it. It was antiseeze got in the boot and was killing the spark.

But i think your problem is a little different.

tepid1

I HAD THE SAME EXACT PROBLEM!!!!

7400rpm misfire. It trashed my pistons and sleeves actually.

Anyway It was because of some interferance in the wiring. I had built a custom engine harness and the distributor wires we too close to sensor wires or my injector driver wires.

tepid1

Also Sean....

Does your wideband log anything lower that 12.0AFR? It looks like it flattened right out just before the misfire. I'm thinking that you might be running much richer and that's just as low as it goes....

darrinbrewer

iTrader: (1)

i'm having almost thesame problem!

my setup was drivin all motor for months, everything OK.

add a turbo and everything, now i miss around 72-7500 rpm

here's what i did(other than obvious turbo items), put in new ngk 7s, gapped at .030, new msd cap and rotor, used blaster3 coil.

air/fuels are 11.3 to 11.6 during missfire (9psi on pump, 9.7:1 pistons)

i'm going to try out a new msd coil and see what happens.

seen4ever

1. This isn't a 400whp build, going for 700+whp. 80 shot of spray plus 30psi on a 3567r... so my goal isn't 400whp, hence why i run the 8s, i just threw in the 9s, as they were laying around and i thought i would try.

2. The wideband is the PLX M250, it reads down to 10.0, I just have managed to get the fuel curve flattened out :-)

One strange thing, moving from the 8s to the 9s, dropped my coolant temp 9 degrees and raised my a/f by .5. I found that a bit strange. The 9s are far too cold for 14psi, but at 30psi with the spray, I'm sure they could work out. Again, i run 8s normally.

When I went to the MSD distributor/ignitor/coil, i was able to open the gap up to .025 just due to the improved performance. With the now OEM distributor, MSD cap, external coil, i've tightened it back down to .020.

I'm thinking its a wire interface somewhere too though, maybe the non-resistor plugs found problems in the 10+yr old wiring harness or something.


Any other suggestions are welcomed, but its just the strangest feeling I've had. Normally a car will pop pretty good on a misfire, never had it just pop constantly and not continue to pull.

On the dyno it was pretty nasty, even made some smoke pop through the twin catchcans, but I checked out the engine to ensure it was still good.

voltage seem low to anyone? I've considered re-doing my cutoff switch, to change where the alternator sends the charged power to.

tepid1

I was running 7's when my problem origionally happened.... so I can't blame my problem on non-resistor plugs. I would bet that you are in the same boat as me too.

Has the harness been modified? Running anything near the ignition/dizzy wires that can cause interferance? Voltage from the Alt is known to cause interferance sometimes....

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by seen4ever &raquo;</TD></TR><TR><TD CLASS="quote"> Normally a car will pop pretty good on a misfire, never had it just pop constantly and not continue to pull.

On the dyno it was pretty nasty, even made some smoke pop through the twin catchcans, but I checked out the engine to ensure it was still good.
</TD></TR></TABLE>

Same here. The MSD dizzy pulled through it better than the OEM dizzy did, but it was still all f'ed up.

In all honesty I would take a flashlight and take a peek down into your cylinders. There could be more to this story.... better yet take the head off and inspect for damage. Seriously....

tepid1

Here is mine.... look familiar?

1


2


3


4

CivicVX94

in for answers....

Turbo-LS

iTrader: (4)

Looks very familiar

seen4ever

Well i did have a J&S on the car, which I removed, that of course ties into the ICM wire, so could be something.

my engine harness is near some of the power wires. I think i may just change all the big power wires around. I've got 0 gauge wire running here and there for the cutoff and a 6 gauge for the ecu cutoff, so I'll set up my switch as everyone else in SFWD. Then try to check out the ecu wiring.

its just strange though.

for you guys with the piston problems, was your leakdown/compression as good as mine?

I just grabbed my blueprint sheet from ERL, .019/.024 rings, .020 ring gap. .0048 skirt clearance on 1, 2 and 4 with .0046 on #3.

any suggestions welcome.

Wait, is everyone having these problems with CP pistons? tepid yours were 84mm I believe, what about everyone else?

seen4ever

maybe the pretty pictures will help

Turbo-LS

iTrader: (4)

my first set was Arias second set was cps. the arias seemed to last longer then the cp's did but i also had a fucccked up sleeve job. i think most peopel are running cp with this issue. im thinkin its a piston issue possibly?

Jared

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo-LS &raquo;</TD></TR><TR><TD CLASS="quote"> i think most peopel are running cp with this issue. im thinkin its a piston issue possibly?</TD></TR></TABLE>

lol, doubt it

seen4ever

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

lol, doubt it</TD></TR></TABLE>

i seriously can't see anything being a piston issue. I also don't see how a expanding skirt would be anything othre than too tight of a tolerance. Plus how the hell does that effect an engine at upper RPMs rather than in the entire range?

just excess heat or osmething?

hell my EGTs are pretty low.

mike93eh2

ive had the same problem, but breaking up and misfiring at 8,300 rpms. most of the time it will shoot out a huge backfire. revlimit in s300 is 8,600.

tried all sorts of things and nothing works so ive learned to deal with it.

Turbo-LS

iTrader: (4)

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

lol, doubt it</TD></TR></TABLE>


Just seems lots of people with black death happen to be running CP pistons. Just because something is new doesnt mean its GOOD. Granted it can be a million different things but dont leave out a piston issue just because you dont think so. ANYTHING and EVERYTHING is possible. thats all i was pointing out

tepid1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by seen4ever &raquo;</TD></TR><TR><TD CLASS="quote">
hell my EGTs are pretty low.</TD></TR></TABLE>

Low EGT's are a sign of detonation. There are a few typs of detonation too. Some are heard.... others are not.

seen4ever

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">

Low EGT's are a sign of detonation. There are a few typs of detonation too. Some are heard.... others are not.</TD></TR></TABLE>

1250 at WOT, i wouldn't say overly low, but nothing overly hot as well.

tepid1

What I ment by that was you would see a dip or spike in temps. That would indicate detonation.

seen4ever

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">What I ment by that was you would see a dip or spike in temps. That would indicate detonation.</TD></TR></TABLE>

got ya

I need to get to the garage to work on it, but I've been lazy. I don't mind wiring, but I hate attempting trouble shooting this type of stuff.