Dr_elusives Swap Question and Progress Thread V 2.0

gio_momma · Apr 13, 2005

Did you read close enough to see that the guy who made the post said EXACTLY the same thing I told you? That the grounds are for the guages, not the motor.

Any time you hook up an electric guage, you need to give the guage a decent ground. Since the engine really has no (nor needs any) reference ground for any of the sensors (besides the O2), if you connect an air/fuel guage to the existing O2 sensor, you need to use the O2 sensor ground (pin 49), so it has the proper reference.

As I said before...adding 1, 10 or 50 extra ground straps won't make any difference in how the car runs, the ECU doesn't ground to the engine in any way.

It can affect the guages, since in many cases they do ground through the engine, but a guage doesn't need a battery cable for a ground, since they barely carry any current at all. If your sender has one wire on it, it grounds through the engine, if it has two, it does not.

Brantley · Apr 13, 2005

gio_momma said:
Did you read close enough to see that the guy who made the post said EXACTLY the same thing I told you? That the grounds are for the guages, not the motor.

Any time you hook up an electric guage, you need to give the guage a decent ground. Since the engine really has no (nor needs any) reference ground for any of the sensors (besides the O2), if you connect an air/fuel guage to the existing O2 sensor, you need to use the O2 sensor ground (pin 49), so it has the proper reference.

As I said before...adding 1, 10 or 50 extra ground straps won't make any difference in how the car runs, the ECU doesn't ground to the engine in any way.

It can affect the guages, since in many cases they do ground through the engine, but a guage doesn't need a battery cable for a ground, since they barely carry any current at all. If your sender has one wire on it, it grounds through the engine, if it has two, it does not.

Hahaha I knew that'd get you all fired up again.

Just thought I'd throw out more reading material for those that wanted to read it.

gio_momma · Apr 13, 2005

I'm not fired up...I'm just glad you finally came around.

evintho · Apr 13, 2005

gio_momma said:
Any time you hook up an electric guage, you need to give the guage a decent ground. Since the engine really has no (nor needs any) reference ground for any of the sensors (besides the O2), if you connect an air/fuel guage to the existing O2 sensor, you need to use the O2 sensor ground (pin 49), so it has the proper reference.

So gio, I had planned to run a ground wire from my A/F gauge to a terminal block (where all my other gauges grounds are connected) and then run a large ground wire to my ground isolators. What your saying is, I need to splice my A/F ground into pinwire 49 to make it work properly?

gio_momma · Apr 13, 2005

evintho said:
So gio, I had planned to run a ground wire from my A/F gauge to a terminal block (where all my other gauges grounds are connected) and then run a large ground wire to my ground isolators. What your saying is, I need to splice my A/F ground into pinwire 49 to make it work properly?

If you're using the factory O2 to run the guage, then you should use the ground for that sensor...which would be pin 49. It's the orange wire that connects from the inlet area of the turbo and goes straight back to the ECU connector.

Mike SVOR · Apr 13, 2005

gio_momma said:
No part of the ECU wiring on a 2.3 turbo, except for the O2 ground is referenced to, grounded to or in any way connected through, any part of the engine...

gio_momma said:
...the grounds are for the guages, not the motor.
....As I said before...adding 1, 10 or 50 extra ground straps won't make any difference in how the car runs, the ECU doesn't ground to the engine in any way.

It can affect the guages, since in many cases they do ground through the engine, but a guage doesn't need a battery cable for a ground, since they barely carry any current at all. If your sender has one wire on it, it grounds through the engine, if it has two, it does not.

Why does the injector harness ground directly to the motor?

The motor needs the Best ground wire you can give it. What could cause a need for this? Maybe a STARTER MOTOR? Perhaps?

When grounding your motor, you should use a 2 gauge or better cable directly to the battery.
This helps the juice transfer directly to the battery instead of going through the frame.

evintho · Apr 13, 2005

gio_momma said:
If you're using the factory O2 to run the guage, then you should use the ground for that sensor...which would be pin 49. It's the orange wire that connects from the inlet area of the turbo and goes straight back to the ECU connector.

Let me explain what I'm doing. I'm swapping an '88 TC motor into an '89 N/A Mustang. I'm using the Mustang's existing wiring harness and I'm using the TC's LA3 computer. On the Mustang's wiring diagram, pin 49, coming from the ECU, grounds to body sheetmetal (seeing as there was no turbo on a N/A motor). My 3 wire connector to the HEGO sensor has a GY/Y fused wire for a hot lead, a DG/P wire as a signal wire and a BK/LG for power ground that goes to pin 60. That's what I got to work with.

The easiest way would be to do like I originally said and run a wire to the T/B then wire to ground isolator (which might not work)
OR
Can I tap into the BK/LG from pin 60 for power ground?
OR
Butt connector from pin 49 wire and run it directly to my new T3 (what you suggested).
Whichever is easiest and will work the best. What d'ya think??

2.3Lxhatch311 · Apr 13, 2005

Don't the spark plugs ground to the motor? I'd say that's a good enough reason to make sure it's grounded right. Dunno If I personally would go welding and splicing stuff... but, ya know, they're 'custom' for a reason.

Brantley · Apr 13, 2005

Sure, in _theory_ the stock grounds should be enough. However, theory and reality on 17+ year old cars are often not the same. I build my car in reality.

Mike SVOR · Apr 13, 2005

2.3Lxhatch311 said:
Don't the spark plugs ground to the motor?

roflmao.....

So far, the motor needs enough ground for the:
Starter
Injectors
Spark Plugs

Can we throw Alternator in there too?

lol

gio_momma · Apr 14, 2005

Mike SVOR said:
Why does the injector harness ground directly to the motor?

They don't.

Some vehicles have a guage ground that goes from the intake to the firewall that's attached to the harness by a zip-tie or tape, but that has no connection to the EFI harness.

gio_momma · Apr 14, 2005

evintho said:
Butt connector from pin 49 wire and run it directly to my new T3 (what you suggested).
Whichever is easiest and will work the best. What d'ya think??

I'd just splice it onto the HEGO ground wire and connect 49 to the turbo like factory on a turbo.

When I splice stuff like that, I don't cut the wire, I use strippers that can pull back the insulation and then solder the other wire over the existing wire...or cut it if you have to then heat shrink it either way.

gio_momma · Apr 14, 2005

Brantley said:
Sure, in _theory_ the stock grounds should be enough. However, theory and reality on 17+ year old cars are often not the same. I build my car in reality.

Your tenous grip on reality really has nothing to do with it. You could weld the motor to the frame and it wouldn't change the electrical connections...because the ECU doesn't ground to the motor.

gio_momma · Apr 14, 2005

Mike SVOR said:
roflmao.....

So far, the motor needs enough ground for the:
Starter
Injectors
Spark Plugs

Can we throw Alternator in there too?

lol

Yeah, you're right...you need a MUCH bigger ground than a postive...LOL

Lesse...got a 4 guage positive cable feeding the starter and a 4 guage negative that goes from the battery to the block...better add 15 more ground straps just in case.

It's amazing to me that people like you can even get up in the morning...I'm surprised you don't bolt your sheets to the bedframe just to make sure you don't fall out of bed.

If you don't understand how this stuff works, you should refrain from giving advice on it.

Mike SVOR · Apr 14, 2005

gio_momma said:
They don't.

Some vehicles have a guage ground that goes from the intake to the firewall that's attached to the harness by a zip-tie or tape, but that has no connection to the EFI harness.

Joe,
The INJECTOR HARNESS has a short wire that grounds to the intake manifold.
It is the ground for the ECU's positive wires going to the injectors. Without that ground, the engine wouldn't run.
This is a factory wire.

Mike SVOR · Apr 14, 2005

gio_momma said:
Yeah, you're right...you need a MUCH bigger ground than a postive...LOL

Lesse...got a 4 guage positive cable feeding the starter and a 4 guage negative that goes from the battery to the block...better add 15 more ground straps just in case.

It's amazing to me that people like you can even get up in the morning...I'm surprised you don't bolt your sheets to the bedframe just to make sure you don't fall out of bed.

If you don't understand how this stuff works, you should refrain from giving advice on it.

First off, who only runs a 4 gauge wire when they're trying to improve the cabling of the car?

The idea here is to use something better for cables than the factory used.
I'll give a brief example of how it should be:

Use zero gauge welding cable for your positive line from your battery to the starter solenoid and from it to the starter.
Use zero gauge welding cable from your negative battery post to the car's frame and from the negative battery post to the engine block.
Ground the back of the cylinder head using a new braided ground strap.
Use the proper gauge cable ends for the wire. Crimp them using a vice grip plier or simular. Heat the cable end using a propane/butane torch. Fill the cable end with solder.
Heat-shrink tubing can be used to cover the soldered section for that "Perfect" look.

and your done.

Welding cable can be found at your local welding supply store.
What makes it better is it has more strands of wire inside.
....be sure to pick up the cable ends while your there.

If your in a pinch, you can go to walmart and grab pre-cut 2 gauge wire lengths with ends and make it work fine in the same manner.
I would avoid doing this just because the cable diameter and cable ends used.
Try zero gauge welding cable.
You won't be disappointed.

2 Gauge welding cable can also be used for this project if 0 gauge can't be used for some reason.

Mike

gio_momma · Apr 14, 2005

Yeah, well the rest of us who are trying to make cars FASTER know that adding 10 or 20 extra pounds of cable to a car does absolutely nothing to "improve the cableing" of the car.

I have 2 guage in the wagon feeding the entire system from the rear of the car (appx 12 feet), from the switch and two stock focus cables (4 guage at best) from the battery to ground and to the switch...cranking a 13:1 motor that runs on alcohol (needs lots of cranking)...with a mechanical pump (takes even more cranking).

Runs great...oh yeah...has no additional ground straps...(doesn't need it, no rubber in the mounts)

The only time you *might* need to add any grounds is if you moved the battery to the trunk and removed the original ground wire. If you do more than 10 feet, go up ONE guage size on the main wire. You can use the stock guage wire (4) for a ground from the chassis to the block and for the battery to the frame...2 looks "cool" and it weighs only a little more. 00, 0 or 1 is totally ridiculous overkill and it weighs WAY too much.

Those of us who have been through the "just started working on cars" phase and have taken the time to actually learn how the cars work don't add additional cabling because some bonehead on the internet tells you to do it.

I guess doing stupid stuff is just part of growing up. Listen to the slow guy who "knows" nothing without Internet message boards...or listen to the guy who makes his money wiring and tuning on professional race cars and trucks (and street stuff).

Turbopit · Apr 14, 2005

Hey, there should be a knock on your door int he next 15-20 minutes.

Mike SVOR · Apr 14, 2005

gio_momma said:
Yeah, well the rest of us who are trying to make cars FASTER know that adding 10 or 20 extra pounds of cable to a car does absolutely nothing to "improve the cableing" of the car.

I have 2 guage in the wagon feeding the entire system from the rear of the car (appx 12 feet), from the switch and two stock focus cables (4 guage at best) from the battery to ground and to the switch...cranking a 13:1 motor that runs on alcohol (needs lots of cranking)...with a mechanical pump (takes even more cranking).

Runs great...oh yeah...has no additional ground straps...(doesn't need it, no rubber in the mounts)

The only time you *might* need to add any grounds is if you moved the battery to the trunk and removed the original ground wire. If you do more than 10 feet, go up ONE guage size on the main wire. You can use the stock guage wire (4) for a ground from the chassis to the block and for the battery to the frame...2 looks "cool" and it weighs only a little more. 00, 0 or 1 is totally ridiculous overkill and it weighs WAY too much.

Those of us who have been through the "just started working on cars" phase and have taken the time to actually learn how the cars work don't add additional cabling because some bonehead on the internet tells you to do it.

I guess doing stupid stuff is just part of growing up. Listen to the slow guy who "knows" nothing without Internet message boards...or listen to the guy who makes his money wiring and tuning on professional race cars and trucks (and street stuff).

This has got to be some of the dumbest junk I've ever read.

Joe, don't you use a motor plate/solid motor mount in your car?

It's a little different when a motor is supported by rubber and isolated from the frame.

You've already proven that you don't know what the hell you're talking about by saying that the EEC doesn't ground to the motor.
So once again, for the people who had a car built for them and have no clue about how to do anything but use 1980's style internet insults and brag about his bought car:

The motor needs grounds for the:
Starter
Injectors
Sparkplugs
Gauges
Alternator

Using high quality wires helps insure that you use all of the battery's performance.

Saying dumb statements like "oh, the factory didn't use high quality wires" is in it's face laughable.
Why would anyone ever get a higher cranking amp battery if the factory's choice was perfect for everyone.

gio_momma · Apr 14, 2005

Mike SVOR said:
Saying dumb statements like "oh, the factory didn't use high quality wires" is in it's face laughable.

Yeah...that would be laughable if I had said it. I never said anything about the quality of the wires.

I did say that the circuit layout is more than adequate is the battery is in the stock location.

And here's a hint just for you Mike...accesories run by the ECU, like solenoids, injectors or relays (any ECU) are "pull to ground". They get B+ through the switch (race deal) or relay (street stuff) and the ground side is switched by the ECU, via the case ground.

Dr_elusives Swap Question and Progress Thread V 2.0

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