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Messages - softtouch

3
Electrical Tech / Re: 22k ohm resistor Ignition wiring dark green / yellow wire from the ign coil
The TFI doesn't need any external resistor to protect it from voltage spikes generated by the coil windings. It is designed to deal with them.

Posted: Some points ignition systems. The negative ends of both windings are tied together internally, the same as the TFI coils.
I believe this was design change from the original Charles Kettering/Delco version. It makes the spark last longer for a cleaner burn.
I believe the original had the high winding grounded to the metal coil casing.
The TFI replaces the points and capacitor.
Posted: Scope pics of the negative side of the coil in a points ignition system.

The voltage developed  by the high voltage winding depends on gap width. When the voltage gets high enough to ionize the air in the gap it arcs across the gap. The ionizing of the air gap causes the gap "resistance" to drop and the voltage to drop.
Posted: 84 Shop Manual pics of spark plug voltage.
5
Electrical Tech / Re: 22k ohm resistor Ignition wiring dark green / yellow wire from the ign coil
Quote from: jcassity – on
y.  there is no reference as to its location as well.   the fella that i was helping told me he found his just a couple feet up the coil harness headed towards the firewall.  His was 100% open.
And there you have it!!! CROSSTALK
The IDM wire and the other TFI wires are bundled together for a couple of feet in the harness before you get to the resistor.
The broke resistor is no longer doing its ignition suppression job.
The high voltage flyback voltage spike is being picked up by the other wires in the harness by what is called crosstalk.
This would explain the erratic PIP pulse error code.
6
Electrical Tech / Re: 22k ohm resistor Ignition wiring dark green / yellow wire from the ign coil
Let me start by saying that the IDM has nothing to do with how the engine runs.
It is one of the things that the Continuous Self Test can look at to see if there is a problem with the pulses between the TFI and the coil. The Continuous Self Test runs while driving the car. If it detects a problem with the IDM, it sets a memory code 18. These are typically intermittent things that the KOEO and KOER tests don't find.
Why the program coders did not include this in the 3.8 continuous self test ? I have no idea.
The 1988 T-Bird EVTM shows the 3.8 has the IDM. I guess they redid the program when they got rid of the CFI and changed the EGR senser and the idle speed control.

If your Mustang guys IDM resister was open, then he probably didn't really have an ignition problem. He had a false code 18 because the monitor circuit was open.
Are you saying IDM is needed for push starting to work?
9
Engine Tech / Re: Misfire - '88 TC
When I did this job I put the distributer shaft in the freezer the night before and heated the gear.
I still had to tap it on, but it may have helped a little.
10
Lounge / Re: AC Power grimlin
Kitchen counter experiment.
6 position power strip with a  three pr0ng cord to a 2 pr0ng receptacle adapter.
The power strip ground is isolated from the receptacle ground.

Pwr strip ground:  to neutral 35.6v, to hot 48.2v,  to a screw on the oven door 36.6v
Pwr strip ground:  thru a toaster and ammeter on 20ma scale to screw on oven door 0 ma.
Pwr strip ground:  thru ammeter on 20ma scale to oven door screw 0 ma
Pwr strip ground: thru my wet finger to oven door screw, no shock

Removed the 2 pr0ng adapter, outlet ground connected to pwr strip ground.
0v between pwr strip ground and oven door screw.

Don't know whats making the o in pr0ng come to up capital or zero?
11
Lounge / Re: AC Power grimlin
You should insure there is no possibility of a difference in electrical potential between any of the metal parts of this bench.
They should all be "bonded" together, with bolts that make a good electrical connection. or ground wires if necessary.
This should include the freezer chest that is close to the bench.

The earth ground is always going to be on your concrete floor, with varying degrees of conductivity based on moisture.
You must be aware of this. As Chuck W pointed out. You might want to consider putting a rubber floor mat in front of the bench.
12
Lounge / Re: AC Power grimlin
I did not mean to imply that you needed the power cord attached to the power strip to create the crosstalk condition.
Your experiments and the, fact that you did not have the power strip cord attached when you got shocked, shows just the ground wire floating in the strip is enough to have the induced voltage in the ground wire.
I believe the reason the induced voltage increases with the UPS is because you have current flowing through the hot and neutral wires.
With no current flow you only have sinewave activity on the hot wire. With current flow there is sinewave activity on both hot and neutral wires.
13
Lounge / Re: AC Power grimlin
The power strip  power cord is unplugged from the wall socket. Your "back feeding" of the power strip is also back feeding the unplugged power strip cord..  The floating ground/bonding wire in the power strip and power cord is picking crosstalk from the other wires. It's acting like the secondary winding of a transformer.
If that power strip case is metal, it should also be connected to the ground wire.
15
Lounge / Re: Blank Boards
There was a similar problem with one of the early web browsers. Maybe Netscape? After an update, every thing went blank.
Turned out it was defaulting to white text on a white background. It was all there, you just couldn't read it.