missing and tach jumping with the miss

[meuhus]

would the ecm cause a miss and the tach to jump with the miss?
i had some injector problems
put in recon. injectors
the car ran sweet
for about a month
had an injector fail
wasn't clicking
it seems that all injectors have pulse
i can not get to middle injectors
to listen to them
replaced failed injector with another recon.
still haveing a miss
i also replace icm
plug wires are new
but they are still arcing to the block and or engine
im going to start there
then i hope to rember to borrow the fluke meter from work
to check injector resitance
i changed fuel filter when i changed injectors
no check engine light
no codes
just wondering if ecm could be bad or in part
the miss is noticable mostly at idle and at a steady speed
and if the car is running about 1500 or lower rpms
when excelerating all seems well
just at idle and steady speeds

what would cause the tach to jump with the engine miss
sounds electrical to me
does the computer get rpm signal from crank sensor/ignition control
mod then send it to the tach
or does the tach connect to icm for its rpm referance signal
the wire diagram in my haynes man. isn't that clear
it shows a white wire that says tach coming from icm
but then it says not used
doesn't show were the tach gets it rpm signal from

i need to pull the plugs and see with one is missing
i connected a plug wire and a plug to each one of the coil terminals
and started car the plug sparked on every terminal
so all coils are working
and it didn't matter with one i had disconnected and hooked up to the test wire and plug
the miss was still there
i have disconected the two injectors i can get to
and the rpms dropped off each time
so i guess i can say its not number 5 or 2
missing
i checked 2 and 4 plugs and they looked good
but for some reson i didn't check 6

i haven't checked front bank and need to

just wondering if anyone has had similar problems
and what they did to fix them
i may just have another bad injector
seems to be worse after the car is in closed loop
thats why i have the ecm thing in my head

but i don't know

91 w/3.1 4 spd auto

[Schurkey]

Missing and tach jumping? First guess: Ignition problem, not fuel problem.

What do you mean "plug wires are new
but they are still arcing to the block and or engine"?

[meuhus]

Originally Posted by Schurkey

Missing and tach jumping? First guess: Ignition problem, not fuel problem.

What do you mean "plug wires are new
but they are still arcing to the block and or engine"?

i had some old plug wires on there
my guess is they were the originals

i replaced them
with double silicon ones from auto zone
and they are still arcing to the engine
from the wire it self
and through the boot to the area around the head were the spark plug goes
if you pop the hood
at night you can see spark (an arc) coming from the plug wires
looks similar to lightning
coming from the wire and going to the engine
in different spots

i will be returning these to az and be getting bosch wire set
hopefully it will be better

and thanks for the dumbass award
if your meaning me

the ignition mod
is new
two new coils
and have had them tested (the coils)
all were good

wires look good that go to icm

i realize that i'm not the dumb ass
sorry

after looking at the other postings

[richtazz]

DO NOT buy the Bosch wires at A-Zone, they are crappier than the ones you bought. Do yourself a favor and buy a set of Delco wires, and make sure when you run them, you don't run them parallel. Try to cross them at some point to keep them from cross-firing. If you ran the wires you have parallel all the way from the coil packs to the rear bank, try crossing them between the front and rear retainers and see if your arcing problem goes away. IF not, take the wires back, get your money, and buy Delco's.

[meuhus]

Originally Posted by richtazz

DO NOT buy the Bosch wires at A-Zone, they are crappier than the ones you bought. Do yourself a favor and buy a set of Delco wires, and make sure when you run them, you don't run them parallel. Try to cross them at some point to keep them from cross-firing. If you ran the wires you have parallel all the way from the coil packs to the rear bank, try crossing them between the front and rear retainers and see if your arcing problem goes away. IF not, take the wires back, get your money, and buy Delco's.

the bosch suck too
great

will they give me my money back

the fronts are more noticable
than the rears

i put that plastic wire loom conduit stuff around the rears
so they wouldn't rub against the engine

[richtazz]

If you bitch, they will. Try being nice first of course, but if you raise enough of a fuss, they'll cave.

[Schurkey]

A guy has to wonder how much voltage it takes to punch through new plug wires.

When was the last time you installed spark plugs?

[richtazz]

A DIS ignition puts out approximately 50,000 volts, so it's not surprizing that cheap wires leak spark. When you run your wires nice and neat in straight parrallel lines, cheap wires are more likely to form a magnetic field between each other. Crossing them breaks this field.

[meuhus]

Originally Posted by Schurkey

A guy has to wonder how much voltage it takes to punch through new plug wires.

When was the last time you installed spark plugs?

there are new ones in now

about 3000 miles on them
regular ac delcos for that car

[Schurkey]

[quote=richtazz]A DIS ignition puts out approximately 50,000 volts, so it's not surprizing that cheap wires leak spark. When you run your wires nice and neat in straight parrallel lines, cheap wires are more likely to form a magnetic field between each other. Crossing them breaks this field.[/QUOTE

A DIS ignition puts out exactly as much voltage as any other coil-fired ignition. And that is "whatever voltage it takes to complete the circuit". (up to the maximum the coil is capable of.)

IF the plugs fire at 12,000 volts, that's all the coil is going to generate.

IF the plugs WON'T fire at 49,000 volts, SOMETHING is wrong. And that's what I'm trying to get to. WHY is this ignition system required to generate enough voltage to punch through new plug wires? My first guess was ancient spark plugs--but that's been taken care of we're told.

GM made claims for 50K volts from the '75 HEI. I'm not buying into the "cheap plug wires" excuse. It's not that hard to make plug wires that hold that much voltage--at least for a little while. Now if the insulation is dirty, or the insulation and/or boots are torn, that's another thing--but it isn't the fault of the plug wire manufacturer. That'd be an installation problem.

Without seeing the vehicle, I'm out of ideas. Sorry.

[edit] Are these FACTORY TERMINATED plug wires, or did you install one terminal on each wire?

[meuhus]

[quote=Schurkey]

Originally Posted by richtazz

A DIS ignition puts out approximately 50,000 volts, so it's not surprizing that cheap wires leak spark. When you run your wires nice and neat in straight parrallel lines, cheap wires are more likely to form a magnetic field between each other. Crossing them breaks this field.[/QUOTE

A DIS ignition puts out exactly as much voltage as any other coil-fired ignition. And that is "whatever voltage it takes to complete the circuit". (up to the maximum the coil is capable of.)

IF the plugs fire at 12,000 volts, that's all the coil is going to generate.

IF the plugs WON'T fire at 49,000 volts, SOMETHING is wrong. And that's what I'm trying to get to. WHY is this ignition system required to generate enough voltage to punch through new plug wires? My first guess was ancient spark plugs--but that's been taken care of we're told.

GM made claims for 50K volts from the '75 HEI. I'm not buying into the "cheap plug wires" excuse. It's not that hard to make plug wires that hold that much voltage--at least for a little while. Now if the insulation is dirty, or the insulation and/or boots are torn, that's another thing--but it isn't the fault of the plug wire manufacturer. That'd be an installation problem.

Without seeing the vehicle, I'm out of ideas. Sorry.

[edit] Are these FACTORY TERMINATED plug wires, or did you install one terminal on each wire?

the wire i got didn't have the numbers for the cylinders on them
i ran the wires like the old ones
i moved them around last night
and it kind seem to help

so if i understand correctly

i shouldn't run the wire to the back
parrell to each other the whole way back
i should cross them when i run them through the
wire retainer clips

[meuhus]

[quote=Schurkey]

Originally Posted by richtazz

A DIS ignition puts out approximately 50,000 volts, so it's not surprizing that cheap wires leak spark. When you run your wires nice and neat in straight parrallel lines, cheap wires are more likely to form a magnetic field between each other. Crossing them breaks this field.[/QUOTE

A DIS ignition puts out exactly as much voltage as any other coil-fired ignition. And that is "whatever voltage it takes to complete the circuit". (up to the maximum the coil is capable of.)

IF the plugs fire at 12,000 volts, that's all the coil is going to generate.

IF the plugs WON'T fire at 49,000 volts, SOMETHING is wrong. And that's what I'm trying to get to. WHY is this ignition system required to generate enough voltage to punch through new plug wires? My first guess was ancient spark plugs--but that's been taken care of we're told.

GM made claims for 50K volts from the '75 HEI. I'm not buying into the "cheap plug wires" excuse. It's not that hard to make plug wires that hold that much voltage--at least for a little while. Now if the insulation is dirty, or the insulation and/or boots are torn, that's another thing--but it isn't the fault of the plug wire manufacturer. That'd be an installation problem.

Without seeing the vehicle, I'm out of ideas. Sorry.

[edit] Are these FACTORY TERMINATED plug wires, or did you install one terminal on each wire?

the wire i got didn't have the numbers for the cylinders on them
i ran the wires like the old ones
i moved them around last night
and it kind of helped

so if i understand correctly

i shouldn't run the wires to the back
parrell to each other the whole way back
i should cross them when i run them through the
wire retainer clips

all the plug wires came assembled
all terminals installed

the only dirt or grease that could be on the wires
is off my hands
from being sort of dirty from changing out the old ones
and i used dielectric grease on the inside of the boots

[tblake]

I am assuming you put new spark plugs in. Did you remember to gap the spark plugs correctly? If they arent gapped, they will require more voltege to jump the gap, and intern that voltage could just be acrhing through your wires onto the block. You used dielectric grease. Did you reall slob it onto the boots? or just put a light dab? You want to smother those boots with that stuff, so it gushes out when you go to pop it on the plug. Is you miss a distince miss every time? Or a random miss? If its distinct, you should be able to narrow it down to a certain cylinder, and that being the case. If you can, try a compression test on it. You may have low compression in one cylinder. If you miss is random, get some ac-delco plugs and some ac-delco wires in there fast.

[ocjmakaveli]

just for laughs pull the egr connector to check if it fixes the tach jumpingall over the place and also did u do the idle relearn
?

[meuhus]

Originally Posted by ocjmakaveli

just for laughs pull the egr connector to check if it fixes the tach jumpingall over the place and also did u do the idle relearn
?

well

thanks again to all

i was hoping that plug wires would change things (fix it)
but they didn't

just for the hell of it i pulled the upper manifold again
and i finally remebered to borrow the fluke meter
from work

check the injectors resitance found one at around four ohms
so i switched it with one of my old ones that measured aroud 12.5
like the rest of them

it fixed every thing
the miss
the tach jumping

car runs great again

91 lumina 3.1 200,000 + mile

later