2g idle adjust BISS potential danger

[bjones18]

I have read many bits on idle adjustment. The most complete being Terry's Talon Troubleshooting... aka idle surge www.dsm.org/how-tos/tttt/tttt3.html. Most information out there is specific to 1g, and recommends grounding a dash panel connector and connecting a logger/grounding a pin.

This thread is specifically to find out if others have experienced sparks or heated wires when attempting this, avoiding miss-haps, and what is the correct 2g procedure.

My 97 Talon has two "un-connected" connectors on the dash panel by the throttle body including a: 1) blue connector and 2) a black connector with cap.

Both of these wires caused sparking or heated wires when grounded and ignition on. With the engine running the blue was at ~12 volts and the black was at 14volts. V=IR with a straight wire (R<1 Ohms) will produce enough amperage to melt wires.

If this method is applicable to 2g cars, one of the following must be true:
1. a resistor must be used between the ground and the connector.
2. proper grounding the pin under the dash (scan tool or logger) must reduce this voltage.

If anyone understands this, please post to prevent potential damage.

Thanks.

 

[steve]

This thread is specifically to find out if others have experienced sparks or heated wires when attempting this, avoiding miss-haps, and what is the correct 2g procedure.

My 97 Talon has two "un-connected" connectors on the dash panel by the throttle body including a: 1) blue connector and 2) a black connector with cap.

Both of these wires caused sparking or heated wires when grounded and ignition on. With the engine running the blue was at ~12 volts and the black was at 14volts. V=IR with a straight wire (R<1 Ohms) will produce enough amperage to melt wires.

If this method is applicable to 2g cars, one of the following must be true:
1. a resistor must be used between the ground and the connector.
2. proper grounding the pin under the dash (scan tool or logger) must reduce this voltage.

I think you'll find that the answer is:
3. None of these wires are the connector your looking for and shouldn't be grounded.

If you were to tell me what the color of the wire running to the connector was I might beable to tell you what these really were for. I'm guessing one is the check connector for the fuel pump.

Steve

 

[bjones18]

Black connector has a cap, and wire is black with lateral white-dash stripes

Blue connector has two wires (that come together) Blue/red and Black/white longitude stripes

 

[steve]

The blue connector with the two wires is the engine speed detect connector between the PTM and the Coil.

The black connector should be the fuel pump test connector but the wire color doesn't match. The manual says it's a black with blue stripe wire like shown below.

http://members.shaw.ca/dsm.1000q/Engineprimer/2G/fuelpumptestconn.htm

Steve

 

[donmagicjuan]

The blue connector with the two wires is the engine speed detect connector between the PTM and the Coil.

The black connector should be the fuel pump test connector but the wire color doesn't match. The manual says it's a black with blue stripe wire like shown below.

http://members.shaw.ca/dsm.1000q/Engineprimer/2G/fuelpumptestconn.htm

Steve

I believe these are the other way around, but I'm not 100% on the black one. When I did my fuel pump rewire, I used the blue connector (fuel pump test connector) for the relay IAW the instructions that came with the kit.

 

[steve]

I think the color of the connectors are swapped too but I was going by bjones18 and Sean Costall wrote. The wiring diagram and photos would support that the blue one is for the fuel pump and the black for the RPM. In bjones18 picture it look pretty clear the the blue one only has one connector inside.

Since I don't have a 2G and don't know if the OP has a 95/96 car that's the best I can do.

Steve

 

[donmagicjuan]

That's a great point. Hey, original poster, why don't you put a car on your profile? You've been a member since 2004!

 

[1LE]

On a 2g, the blue connector is tach. Don't know what the black connector is, I don't have one. The appropriate one to ground is the brown connector (at least on '95, I hear that it may or may not exist in '96+, and a DSMlink or MUT-II is required instead).

 

[donmagicjuan]

On a 2g, the blue connector is tach. Don't know what the black connector is, I don't have one. The appropriate one to ground is the brown connector (at least on '95, I hear that it may or may not exist in '96+, and a DSMlink or MUT-II is required instead).

It's possible then that the connectors differred from the 2GAs to the 2GBs. I don't think I'd have much success running my fuel pump relay off of a variable voltage source. Furthermore, if it was the tach, I don't think my pump would energize with the ignition in ON and the engine not running, which is definitely the case.

But again, we can't really help the OP without knowing the year of his car.

EDIT: Just saw that in the original post he mentions it's a 97.

 

[1LE]

EDIT: Just saw that in the original post he mentions it's a 97.

Oh, OK, I guess I missed that too! '97+ (technically on '96 as well, but I've heard of '96's with the same connectors as the '95), the ONLY "supported" method of properly setting the BISS involves using a MUT-II. If you don't have the extra $6,000 laying around to buy one and you don't trust the local dealer enough to do it, you can just twiddle the BISS around a little once every few days until you get it "close enough"