I have been struggling with this for a few weeks and have no luck yet. I have a v2.2 board running MSnS-E 029n. I have a 36-1 wheel and am using the GT1 honeywell hall sensor to read it. My opto circuit was modified exactly like this:
http://megasquirt.sourceforge.net/extra ... t-neg5.jpg
I am runnign VB921s for the outputs. I have them driven with 690 ohm resistors (in the hope that 330 was just not enough! - no change) They are grounded by a separate wire to the head (star ground point). The outputs are running on a pigtail out of the MS box. The coil pack is a Ford EDIS coilpack (4 cyl). I have the Ford noise cap connected (next to the coils) and am running resistor plugs (these helped - with non resistor plugs, it was so noisy it was resetting all the time at idle and it was undrivable)
Via tooth logger, I get perfect 36-1 waveform. Under boost, I can get nasty RPM spikes. At idle and partial throttle it is smooth as silk. With the same timing map and dwell settings, but only driving a single coil I never had a problem. As soon as I went to wasted spark, the problem started.
This is a sample log:
http://www.wideopenwest.com/~kgrider/sa ... 120848.xls
I am trying to go to COP, but this is with W/S setup, so I cannot go to COP until this is resolved. More info here:
http://www.msefi.com/viewtopic.php?t=17 ... c&start=10
help with RPM spikes
Moderators: jsmcortina, muythaibxr
What kind of spark plug wires are you using ?
What are your Plug Gaps set to ?
If you are using solid wire spark plug wires , throw them away and get some
"Spiral Core" wires , Solid Wires are death to electronics , they put out
tons of electrical noise .
If your plug gaps are too big you could create internal arcing inside
your ignition coils .
I have not experimented with my EDIS to see how large of a plug gap
the coils will support .
Here's the deal on plug gaps :
In open air , the spark plug gap represents a certain amount of resistance ,
lets say just for example , that it takes 1,000 volts to jump a .050 gap
in open air , this is at atmospheric pressure , 14.5 psi absolute pressure ,
now put it in an engine cylinder and compress the air to 150 psi , now
the air is 10 times more dense , so it takes 10 times as much voltage
to jump the same gap or 10,000 volts , this is the same as increasing
the plug gap to one half of an inch !!!
Using the same principle , if you double the plug gap to .10 you would
double the voltage required to jump the gap .
Now on top of all that , with a Turbo , you are increasing your cylinder
pressure before the piston even starts to compress it ,
increasing the voltage requirement even futher .
At some point the insulation inside the coil will start to break down , so
instead of the spark jumping the plug gap it takes the easiest route to ground ,
in this case it could be the primary winding in the coil , this will radiate
electrical trash noise all throughout your electrical system .
Sometimes this can ruin the Coil Pack , you may have to replace it .
Of course you could have a bad coil already .
This is NOT a MS problem .
Start by reducing you plug gaps down to .030 ,
this may clear up some of the problem .
Since you say you want to change to C.O.P. ignition you probably aren't
interested in spending money on your present set-up , but I'll give you
my recomendations on plug wires anyway in case someone else reads this post .
Accel p/n ACC-5041Y the letter on the end is the color ,
Y is yellow , B is Blue , K is Black , R is Red .
This is a "Universal" set for a V-8 , they are 8mm Spiral Core Wires with
no connector installed on the Coil/Dizzy end ,
it comes with 2 different types of distributor boots .
The extra wires allow for the ones you will screw up when assembling them ,
it also means you will have at least 4 really long wires so you
can put your coil pack in a convenient spot .
For EDIS you will also have to have this kit :
Accel p/n 170065 , these are special EDIS Coil Connectors and Boots
to use with any universal wire set .
You can get this stuff from Summit Racing ,
both together cost about $100.oo .
This is the p/n for an Accel EDIS Coil Pack ACC-140018 , about $55.oo .
You may benifit from this coil with a Turbo .
...................Jim
What are your Plug Gaps set to ?
If you are using solid wire spark plug wires , throw them away and get some
"Spiral Core" wires , Solid Wires are death to electronics , they put out
tons of electrical noise .
If your plug gaps are too big you could create internal arcing inside
your ignition coils .
I have not experimented with my EDIS to see how large of a plug gap
the coils will support .
Here's the deal on plug gaps :
In open air , the spark plug gap represents a certain amount of resistance ,
lets say just for example , that it takes 1,000 volts to jump a .050 gap
in open air , this is at atmospheric pressure , 14.5 psi absolute pressure ,
now put it in an engine cylinder and compress the air to 150 psi , now
the air is 10 times more dense , so it takes 10 times as much voltage
to jump the same gap or 10,000 volts , this is the same as increasing
the plug gap to one half of an inch !!!
Using the same principle , if you double the plug gap to .10 you would
double the voltage required to jump the gap .
Now on top of all that , with a Turbo , you are increasing your cylinder
pressure before the piston even starts to compress it ,
increasing the voltage requirement even futher .
At some point the insulation inside the coil will start to break down , so
instead of the spark jumping the plug gap it takes the easiest route to ground ,
in this case it could be the primary winding in the coil , this will radiate
electrical trash noise all throughout your electrical system .
Sometimes this can ruin the Coil Pack , you may have to replace it .
Of course you could have a bad coil already .
This is NOT a MS problem .
Start by reducing you plug gaps down to .030 ,
this may clear up some of the problem .
Since you say you want to change to C.O.P. ignition you probably aren't
interested in spending money on your present set-up , but I'll give you
my recomendations on plug wires anyway in case someone else reads this post .
Accel p/n ACC-5041Y the letter on the end is the color ,
Y is yellow , B is Blue , K is Black , R is Red .
This is a "Universal" set for a V-8 , they are 8mm Spiral Core Wires with
no connector installed on the Coil/Dizzy end ,
it comes with 2 different types of distributor boots .
The extra wires allow for the ones you will screw up when assembling them ,
it also means you will have at least 4 really long wires so you
can put your coil pack in a convenient spot .
For EDIS you will also have to have this kit :
Accel p/n 170065 , these are special EDIS Coil Connectors and Boots
to use with any universal wire set .
You can get this stuff from Summit Racing ,
both together cost about $100.oo .
This is the p/n for an Accel EDIS Coil Pack ACC-140018 , about $55.oo .
You may benifit from this coil with a Turbo .
...................Jim
'95 GM 4.3 Vortec V-6
Single Plane Intake w/ported GM Throttle Body
Ported Heads , stock roller cam retarded 8 degrees
MS-II 2.6 , V-3 board , MT 3.0
EDIS ignition , Innovate WB 02
250hp , 28mpg @60mph in a 2 ton wagon
Single Plane Intake w/ported GM Throttle Body
Ported Heads , stock roller cam retarded 8 degrees
MS-II 2.6 , V-3 board , MT 3.0
EDIS ignition , Innovate WB 02
250hp , 28mpg @60mph in a 2 ton wagon
-
Keithg
- Super MS/Extra'er
- Posts: 2413
- Joined: Sun Mar 06, 2005 9:15 am
- Location: Chicago, IL, USA
- Contact:
help with RPM spikes
Jim,
Thx for the input. I am running NGK BCPR7ES11 plugs . Resistor plugs.
With regular plugs it was noise city. Resets all the time it wouldn't
even idle. I have a set of standard ford EDIS plug wires. I actually
have both types and I get the same deal with both. Start and idle are
fine. Moderate load is fine. WOT is a problem. I have them gapped to
1mm (0.039"). That is spec for the stock ford EDIS I think and as well
for the COP system I will be going to eventually. It has to be
something more than that, though. I am running a bit of boost when the
problem happens (160kpa+) I have a hunch is it the V2.2 board more
than anything specific, but gap may help. If I get a chance, I'll try
0.032 gap ands see what happens. The V3 has better noise immunity and
is better protected. To really see it, I have to scope it while I am
driving and that proves difficult. If I can get a partner in this,
I'll take a look. If it goes away with the COP system I will be
installing shortly, then it will be an unknown. If not, I'll have to
trace it down. The odd thing is that with a single MSD blaster coil it
was never a problem. It only showed up when I went to the EDIS coil
pack. That was the only change. The proof is with the scope and I just
have not had an opportuinity to do that yet.
KeithG
Posted by email.
Thx for the input. I am running NGK BCPR7ES11 plugs . Resistor plugs.
With regular plugs it was noise city. Resets all the time it wouldn't
even idle. I have a set of standard ford EDIS plug wires. I actually
have both types and I get the same deal with both. Start and idle are
fine. Moderate load is fine. WOT is a problem. I have them gapped to
1mm (0.039"). That is spec for the stock ford EDIS I think and as well
for the COP system I will be going to eventually. It has to be
something more than that, though. I am running a bit of boost when the
problem happens (160kpa+) I have a hunch is it the V2.2 board more
than anything specific, but gap may help. If I get a chance, I'll try
0.032 gap ands see what happens. The V3 has better noise immunity and
is better protected. To really see it, I have to scope it while I am
driving and that proves difficult. If I can get a partner in this,
I'll take a look. If it goes away with the COP system I will be
installing shortly, then it will be an unknown. If not, I'll have to
trace it down. The odd thing is that with a single MSD blaster coil it
was never a problem. It only showed up when I went to the EDIS coil
pack. That was the only change. The proof is with the scope and I just
have not had an opportuinity to do that yet.
KeithG
Posted by email.
The only change was from MSD/one coil to EDIS .
In order to run the EDIS Coil Pack you changed from outputing a
"control signal" with very little current flow and NO noise , to running
a hideously noisy ignition coil wire pulling 6 to 8 amps INSIDE your MS .
Running that high current , very noisy stuff ,
INSIDE your MS is very bad practice , those switching transistors need
to be mounted somewhere else , I have read where other people have
successfully run like this , but personally , having tinkered with all sorts
of electronics for 40 years , I wouldn't even consider even having those
wires run within 3 or 4 inches of MS .
On a good note , with COP ,
those wires won't be carrying all that heavy current and electrical Trash .
Also the MSD didn't introduce that curent or trash either .
Do you see a pattern emerging here ?
That MAY be all of it , never the less , continue.....
If just changing the plugs made all that difference , you must also be
broadcasting noise from the pimary of the Coil Pack .
Where is your EDIS Coil Pack powered ?
The stock noise capacitors do go out occasionally .
You should power the coils directly from the battery through
an "Inline Fuse Holder" , not anything associated with MS ,
it doesn't need to be switched .
...................Jim
In order to run the EDIS Coil Pack you changed from outputing a
"control signal" with very little current flow and NO noise , to running
a hideously noisy ignition coil wire pulling 6 to 8 amps INSIDE your MS .
Running that high current , very noisy stuff ,
INSIDE your MS is very bad practice , those switching transistors need
to be mounted somewhere else , I have read where other people have
successfully run like this , but personally , having tinkered with all sorts
of electronics for 40 years , I wouldn't even consider even having those
wires run within 3 or 4 inches of MS .
On a good note , with COP ,
those wires won't be carrying all that heavy current and electrical Trash .
Also the MSD didn't introduce that curent or trash either .
Do you see a pattern emerging here ?
That MAY be all of it , never the less , continue.....
If just changing the plugs made all that difference , you must also be
broadcasting noise from the pimary of the Coil Pack .
Where is your EDIS Coil Pack powered ?
The stock noise capacitors do go out occasionally .
You should power the coils directly from the battery through
an "Inline Fuse Holder" , not anything associated with MS ,
it doesn't need to be switched .
...................Jim
'95 GM 4.3 Vortec V-6
Single Plane Intake w/ported GM Throttle Body
Ported Heads , stock roller cam retarded 8 degrees
MS-II 2.6 , V-3 board , MT 3.0
EDIS ignition , Innovate WB 02
250hp , 28mpg @60mph in a 2 ton wagon
Single Plane Intake w/ported GM Throttle Body
Ported Heads , stock roller cam retarded 8 degrees
MS-II 2.6 , V-3 board , MT 3.0
EDIS ignition , Innovate WB 02
250hp , 28mpg @60mph in a 2 ton wagon
-
Keithg
- Super MS/Extra'er
- Posts: 2413
- Joined: Sun Mar 06, 2005 9:15 am
- Location: Chicago, IL, USA
- Contact:
help with RPM spikes
on mine it is powered by the fuel pump relay.
KeithG
Posted by email.
KeithG
Posted by email.
-
Keithg
- Super MS/Extra'er
- Posts: 2413
- Joined: Sun Mar 06, 2005 9:15 am
- Location: Chicago, IL, USA
- Contact:
help with RPM spikes
Jim,
to be clear, it was a single vb921 mounted in the case driving a MSD
blaster coil (regular coil, not a MSD ignition box). When I switched
the second vb921 on to drive both channels of the EDIS coilpack, is
when the problem surfaced. The change was 1) turning on both outputs
and 2) the coilpack was powered from the fuel pump relay instead of
the OEM wire harness.
The stock EDIS cap is connected, though I have not verified that it is
still good.
I had not thought of that, but the only other difference is that the
single coil was powered by the stock wiring harness and the EDIS is
powered by the fuel pump relay. I can easily enough connect the EDIS
pack to the stock coil power lead and see if that helps.
KeithG
Posted by email.
to be clear, it was a single vb921 mounted in the case driving a MSD
blaster coil (regular coil, not a MSD ignition box). When I switched
the second vb921 on to drive both channels of the EDIS coilpack, is
when the problem surfaced. The change was 1) turning on both outputs
and 2) the coilpack was powered from the fuel pump relay instead of
the OEM wire harness.
The stock EDIS cap is connected, though I have not verified that it is
still good.
I had not thought of that, but the only other difference is that the
single coil was powered by the stock wiring harness and the EDIS is
powered by the fuel pump relay. I can easily enough connect the EDIS
pack to the stock coil power lead and see if that helps.
KeithG
Posted by email.