BlackRx7

Well the neg battery cable on my car goes from the neg termial to the side of the driver side strut tower (heh not the firewall) then to the starter motor....

yearrgh

Not to mention you might cook yourself!

GeeHee13B

i couldnt find that either

BlackRx7

back track it from the starter, then to the neg battery terminal, maybe and aftermarket ground was installed to mine?

ggyygg88

i cant find the ground wire from the fuel injection harness...i was wondering if you could post a better pic. i grounded the rest of the wires you recommended and now the 7 is runnin a lot better. thanks a lot!

BlackRx7

Yeah sorry I'm just busy with work and all, I have off on Tuesday and i'll try to get a better shot for you

smith88

I have grounded my leading and trailing coils and the fuse box that is in the engine bay. And now my idle is running a little smoother. I'm going to do the other grounds soon just to make sure everything has good connections.

I'd really like to see those fuel rail pics.

Thanks for the great info in this post!!!

javrosario

iTrader: (5)

Hrm, which ground are you talking about from the battery. Is it the one that goes attached to upper driver side transmition bolt? near the oil filter? that ground?

BlackRx7

my cars neg battery cable goes from the terminal to the fuse box then to the driver side strut tower then to the transmition bolt

BlackRx7

Okay finally I got the fuel injection harness pictures, sorry for the long delay, hopefully these pictures will help, let me know if you want me to post them with out my crappy illustration

the blue is the fuel injection harness, the green is the 8 guage ground wire running to the chassis ground

Top view



Side View



lemme know if you want more pics....

Rotory

iTrader: (1)

man i just cant tell what you guys are talking about...im an idiot

BlackRx7

Once you remove the UIM it should be pretty easy to spot, if you still can't find it, unplug you injector clips and trace the harness to the ground

Templeswain

Sorry for jumping in the middle of this all of the sudden.

I've read some of the this thread to understand that this is an electrical issue, or so I gather.

My 88 GXL is out of control.

When the car is off the Tacometer is flipping out. When its running the car sputters and all the dash lights freak when the accelerator is depressed..

Someone mentioned that problems like this can arrise because the original ground is not, well....grounded.

I will study this thread but, what I really want to know is: Am I on the right tack or should I just dump my 7 into the lake behind my house?

BlackRx7

Never dump an RX7 into a lake!!!! First off I try and see what codes the engine is throwing, but grounding will deffinatly not make the situation worse but it is a good start, on a 1 to 10 scale of 1 being puting stickers on your car to 10 being rebuilding, I'd give it about a 3

Templeswain

It was a grounding issue.

The thermostat was malfunctioning. For some reason the antifreeze overflow is located almost directly over the Lead Coil. It was filling the overflow up, and literally overflowing onto the lead coil.

Then, there's this wire that connects to the fire wall and is grounded onto the Block. It was completely melted.

So I replaced the wire and thermostat. Viola! Tach, works everything works again.

Interesting is that I still have no idea whether or not a coil drenched with anifreeze is enough to cause a grounding wire, totally unconected to the coil itself, to fry. Perhaps they were two seperate but coincident problems?

Whatever, its fixed.

Thanks again.

JGard18

One comment I'd like to throw into the mix about this.

People with brand new Subaru Imprezas and brand new Mitsubishi EVOs are doing a "grounding mod" to their cars, and seeing immediate improvements. Mostly in smoothness of idle, but they also says it seems to pull more evenly throughout the powerband.

So don't just think of grounding as something to do to an older, more worn, car. It can even work wonders on brand new vehicles.

cswanson

Very good post- I've got the boost sensor and both of the coils in my '86 GXL grounded. The infamous 3800 RPM lag has almost totally disappeared. I'm having trouble locating the injector harness, though. Also, it appears to me that my firewall ground is a "slip on" connector with the male part attached to the firewall. For a car with so many apparent grounding problems, this seems very inadequate. Am I mistaken? Can I ground both coils to the battery?

BlackRx7

actually I think that slip on connector on the firewall is the harness ground for N/As. I believe the turbos have it on or near the intercooler bracket like mine...but don't know for sure. Yes you can ground both coils to the battery thats basically what I did

Nova7

iTrader: (5)

Thought I'd pass on something I found for what it's worth. I did most of the ground fixes listed on this forum. Does help! However, I found one major ground point that has not been mentioned--or else I missed it. Under the Trailing Coil and its mount is a white connector (at least on my 87 GXL) that looks like it connects to the strut tower. It does! It's a ground for five wires. There's a copper piece that is the male side of the plug that bolts to the strut tower. I would suggest cleaning that one up well too as it must ground many circuits!

JunpoweR

iTrader: (1)

Today I Grounded My GTUs
yesterday Punched out my 2nd and 3rd Cats..
sounds LOUD and DEEP.. not bad for a Ghetto Job..
It was Enough to Beat my friends GSL-SE with Smaller gears..which pulled a 15.1 at sears point in the 1\4 mile.. so it must be in the high 14's somewhere
Also The Grounding Was Only to My Leading and Another to my Trailing Coils..

this modification did great!!!
when i step on breaks the rpm dosent bounce down then up..

i used doubled wires..and crimp connector ends also wires welded to crimps..

i used 2 X 12 Gauge wires twisted up together for each ground because i didnt have a thicker wire..

seems like it did the Job..

i will post pics Soon..

the annihilator

how many watts was your soldering iron that you used for the grounding?

BlackRx7

not sure of the top of my head, but it was the pencil style iron that I bought at Radio Shack for like 6 bucks i think...I don't think you need any major wattage though.

cswanson

Where is the ECU (86 GXL)?????
I've seen pictures of it in this post and in my factory manual, but nobody says where it is.

Nova7

iTrader: (5)

The ECU is where the passengers feet go! It's under the carpet and a metal panel in the corner of the floor pan and the firewall. Just pull off the plastic kick panel on the right, the piece that covers the carpet edge against the rocker panel and pull back the carpet. You'll see the metal panel held on by two bolts and two nuts. Remove it and voila, the ECU!

cswanson

Thanks. Next question- I'm searching my engine compartment (86 GXL) for ANY ground connections to re-do. I found two (so far) where a wire comes out of a bundle and is bolted to either the engine block or a body panel. However, they are not simply wires with a ring connector crimped on the end. They both have small black "boxes" where the wire goes in one side and the ring connector is on the othe side. What are these things?