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RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections.

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Old 04-24-2009, 07:25 PM   #1
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Default How to ground you N/A FC ver. 1

Hey folks I am thinking of making a sticky Faq here for everyone who has added grounds and or cleaned them.. let me know what you know about grounds... I will be collecting info from other sites and posting the write-ups, and links to the orginal link.
So post away what you know about ground and the benefits you have..






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Old 04-25-2009, 04:36 PM   #2
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I'm a believer of just cleaning the factory grounds. The ones on my car have worked for the past 23 years so I kind of doubt I would need to add more. The only time I suggest adding a ground is for the 3800 rpm hesitation. However, that only applies to '86 and, I think, up to '87.5 cars.
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Old 04-25-2009, 05:08 PM   #3
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I ran 2 wires from B- to the tab on the firewall that runs to the top of the engine for the pcm ground. I still have the slight 3800 hesitation that I've always had.
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Old 04-25-2009, 06:10 PM   #4
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there is a tech article i wrote in general info that has all to do with grounds. i quick smear of di-electric grease on ground points will ensure they dont corrode
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Old 04-25-2009, 09:17 PM   #5
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Originally Posted by SecondGenPat View Post
I ran 2 wires from B- to the tab on the firewall that runs to the top of the engine for the pcm ground. I still have the slight 3800 hesitation that I've always had.
The 3800 hesitation is due to a specific ground, namely the one coming off the pressure sensor (in the engine bay). You can either reground right next to the ECU, or do what I did and splice in a new ground to that wire in the engine bay.
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Old 04-30-2009, 12:19 PM   #6
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I just wire wheeled all the factory grounds and ran a semi thick gauge wire between all of them that loops from engine group to ECU ground. no hesitation here!

I also did re ground the map sensor too.
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Old 04-30-2009, 03:55 PM   #7
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Which wire on the pressure sensor is the ground? Is it the black one with the white stripe? Im assuming it is being as black is usually ground but i dont want to go ground the wrong wire lol.

EDIT: Found a diagram, no more hesitaion YAY!!

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Old 04-30-2009, 06:36 PM   #8
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I would like to chime in: I cleaned my grounds, however the wire inside the insulation and the insualtion itself were in such terrible shape, I had to unwrap the engine wiring harness, cut out a large section of the ground wire (including both on-engine ground terminals) and solder in new wire and B-Crimp (OEM style crimping method) ground terminals. This is an exteme case however.
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Old 04-30-2009, 06:41 PM   #9
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Im kind of scared about what my harness really looks like, last time i had to peel back the tape on the main harness from the computer it was full of old coolant (shudder......)
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Old 04-30-2009, 07:19 PM   #10
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Kind of a stupid question (I'm an electrical noob lol), but for the pressure sensor reground, do you basically just cut the wire, and solder the ends back together with a 3rd wire added to the joint, and ground that 3rd wire?

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Old 05-01-2009, 09:43 AM   #11
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Originally Posted by need RX7 View Post
Kind of a stupid question (I'm an electrical noob lol), but for the pressure sensor reground, do you basically just cut the wire, and solder the ends back together with a 3rd wire added to the joint, and ground that 3rd wire?

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Yeah. I would also suggest cleaning the factory ground point as well.
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Old 05-04-2009, 06:26 PM   #12
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i did the hks circle earth system, gold plate to negative battery with 6 wires coming off to engine, one to each of the housings and one to each of the irons
and one to the main harness ground. i have no hesitation at any point, and no more bogging from starts. this is in my 90 GTUs
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Old 05-06-2009, 07:00 AM   #13
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Quote:
Originally Posted by Fidelity101 View Post
I just wire wheeled all the factory grounds and ran a semi thick gauge wire between all of them that loops from engine group to ECU ground. no hesitation here!

I also did re ground the map sensor too.
Nicely done.

Quote:
Originally Posted by takahaski.r View Post
i did the hks circle earth system, gold plate to negative battery with 6 wires coming off to engine, one to each of the housings and one to each of the irons
and one to the main harness ground. i have no hesitation at any point, and no more bogging from starts. this is in my 90 GTUs
I think that HKS thing is a waste of hard earned money. You could've done the entire thing yourself for much cheaper. Also, grounding the int and front iron are kind of a waste. The rear holds the coolant sensor for the gauge, so that is kinda nice to re-ground.

The housings are key for good spark so I would definately ground those, as well the ECU points, housings, waterpump housing, TPS, pressure sensor, and maybe the MAF. Everything should be common and leading to a GOOD chassis ground or to the battery. When I did mine I started with an 8 gauge grounded by the ECU that spiderwebbed out with CRIMPS (NOT solder) to hit all the key points.
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