Power, No power. Repeat. (video)

[IwantMKIII]

I've had this problem since the rebuild. I thought i figured it out when i found the injectors were miswired, but did not help.

Problem: Rapid, on off power throughout RPM. Most noticeable when engine is cold but still noticeable at any temp. Boost it is noticeable extra as well most likely since im producing all the more power then all the less.

What ive done:

-Replaced plugs
-new wires
-check coil packs - all getting voltage and all proper resistance
-CPS - all proper resistances
-ISC - all proper resistances
-Ignitor - i assume is working since coils are getting voltage?
-Rewired and rechecked injector wiring
-Monitored AFM readings, checked out ok: 34Hz at 1K idle, 1400+hz full throttle
-Boost leak test - none
-Vacuum system - tested with boost test, no leaks
-New feul filter

FYI - injectors are RC injectors, bought new. Have 4K on them along with the engine


Symptoms:

-On off power most noticeable when cold
-High idle, ~1K


System readings:

-20-25 inHg vacuum
-Boost full 12-12.8PSI and holds
-oil pressure 5-40PSI, 60-70+PSI cold start
-AFM - 35Hz idle
-Knock senor - 0
-Idle ~1K
-Fuel pressure - 38PSI idle, 58PSI full boost
- Temps - normal 150-200 depending on conditions
- AFR - KEY Power is syncronous with AFR seen in vid below. This is a narrow band AFR (this is not used to tune), however power issues are in sync with it. Red is lean, green is rich. Counterclockwise = leaning out.


You can see in vid AFR remains steady breifly then dramtically oscillates as does the power. noctice tach in background is steady.

http://www.youtube.com/watch?v=y_sQSQBsobA

EDIT (add on)
Pulled plug 6 and 4 to check what they look like with about 2.5K miles on em:

Pics came out a bit blurry but they seem like they are much more black then they should be.

Spark #6 a


Spark #6 b


Spark #4



Also wondered if anyone could tell me if this wire should be attatched somewhere? if so where?



EDIT 2

Replaced ignitor just in case. No change. Odds of two bad ignitors are very very slim from what i understand.

 

[MDCmotorsports]

Not sure what your problem is, but I can tell you that trying to tune with a narrow band o2 sensor guage is a no no.....

 

[IwantMKIII]

Not sure what your problem is, but I can tell you that trying to tune with a narrow band o2 sensor guage is a no no.....

im not, its just somethings to help identify problems with, such as this.

edit: tuning was done professionally with wideband and dyno

 

[IwantMKIII]

bump for help

 

[jtamulis]

What plugs are you using?

 

[IwantMKIII]

What plugs are you using?

plugs used originally were NGK-R (laser cut)


EDIT: I'm using NGK v-power, which are copper

 

[jtamulis]

replaced with NGK platinums

Likely your problem. 99% of all the 7M's I see coming through won't work well
with platinums. Go get your self a set of COPPER (read cheap $1.98 plugs).

I bet your misfire goes away. It's by FAR the most common MKIII problem I've
run across in my years of MKIII work .

Jeff

 

[hellraiser456]

well if you are having issues with your afr's then i would start looking at what affects that. are you sure you have spark at all six plugs. the power band looks as though you have have a bad coil. because it seems to vary at a steady pace. because there is unburnt fuel (and tons of o2 because combustion didn't occur) you o2 sesor would read very lean...then back to stoich/rich i would look into your spark first.


you can test by pulling your wires and turn the car over and ground out a spare spark plug somewhere.

 

[IwantMKIII]

Likely your problem. 99% of all the 7M's I see coming through won't work well
with platinums. Go get your self a set of COPPER (read cheap $1.98 plugs).

I bet your misfire goes away. It's by FAR the most common MKIII problem I've
run across in my years of MKIII work .

Jeff

any particular reason why? they are recomended and all but i have seen this before. Also, ive had the same problem through two different types of NGK plugs, one expensive one cheap, what are the odds of that?

 

[IwantMKIII]

well if you are having issues with your afr's then i would start looking at what affects that. are you sure you have spark at all six plugs. the power band looks as though you have have a bad coil. because it seems to vary at a steady pace. because there is unburnt fuel (and tons of o2 because combustion didn't occur) you o2 sesor would read very lean...then back to stoich/rich i would look into your spark first.


you can test by pulling your wires and turn the car over and ground out a spare spark plug somewhere.

Ill try this but i figured resistance checking the coil packs would do the job. All coil packs are recieving 12V's as well, but ill try this just in case. Who knows, maybe somehow the wires are bad already?

 

[jtamulis]

something about the platnium plugs disrupts the 7M-GTE's Coil pack signal
or something like that. It's been a while since I knew the technical reason, but
It'll ALWAYS be the first thing I check when a MKIII is missing at all.

Jeff

 

[jetjock]

99% of all the 7M's I see coming through won't work well with platinums.

That must be why they all came from Toyota with them

 

[jtamulis]

I should have said NGK Platniums.

Jeff

 

[IwantMKIII]

something about the platnium plugs disrupts the 7M-GTE's Coil pack signal
or something like that. It's been a while since I knew the technical reason, but
It'll ALWAYS be the first thing I check when a MKIII is missing at all.

Jeff

well i just realized they MAY be copper. I have the V-power's by NGK. I can't find if they are copper or platinum tipped though??

EDIT turns out V-power are copper core plugs.

 

[IwantMKIII]

Pulled plug 6 and 4 to check what they look like with about 2.5K miles on em:

Pics came out a bit blurry but they seem like they are much more black then they should be.

Spark #6 a


Spark #6 b


Spark #4



Also wondered if anyone could tell me if this wire should be attatched somewhere? if so where?

 

[starscream5000]

What gap are you using on your plugs?

What heat range also?

 

[IwantMKIII]

What gap are you using on your plugs?

What heat range also?

.032gap

NGK level 6 heat range plug

 

[marlonvip]

Hi Ivan,

Im pretty sure the plug goes on a pin comming from the termostat housing:.-)

~Marlon~

Pulled plug 6 and 4 to check what they look like with about 2.5K miles on em:

Pics came out a bit blurry but they seem like they are much more black then they should be.

Spark #6 a


Spark #6 b


Spark #4



Also wondered if anyone could tell me if this wire should be attatched somewhere? if so where?

 

[TheNewRed]

Also wondered if anyone could tell me if this wire should be attatched somewhere? if so where?

[/QUOTE]

This connector goes to the top sensor that is screwed into the thermo housing atleast thats what it looks like if not check a wring diagram. on mine there are three sensors, when i was checking the connectors to this one, it poped off into my hand:biglaugh: .

 

[IwantMKIII]

IS it possible this is from a bad tune?