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Cleaning electrical grounds

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Old May 20, 2013 | 08:25 PM
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Default Cleaning electrical grounds

I noticed in a prior topic a member was told to check voltage at the battery and to clean all the grounds before tearing into the electrical system looking for a short or to correct a low voltage situation. My battery strap was a bit corroded even though it was replaced 3 years ago and that helped some on the low voltage. How many grounds are there and where are they located on a 82 so I can clean them all. Thanks.
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Old May 20, 2013 | 08:34 PM
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Here you go
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Old May 20, 2013 | 08:37 PM
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Default Ground mp ix

87s4 what grounds at mp ix? I have 2 eyelets from fuel injector grounded at mp viii...and nothing at mp ix
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Old May 20, 2013 | 08:49 PM
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Originally Posted by newworld
87s4 what grounds at mp ix? I have 2 eyelets from fuel injector grounded at mp viii...and nothing at mp ix
MP IX could be on the cam cover or under the car
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Old May 20, 2013 | 09:00 PM
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Originally Posted by longleader
MP IX could be on the cam cover or under the car
MP IX is on passenger side atop the bell house. Accessed by removing air filter housing and fuel regulator-dampener set.
It grounds the following:
MAF
LH control unit
EZK control unit
Throttle valve switch
Potentiometer (?)
Coding and Tester Plugs

Last edited by MainePorsche; May 21, 2013 at 01:37 AM.
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Old May 20, 2013 | 09:39 PM
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Usually, the grounds under the regulator and dampers have corrosion on the connectors. Clean them with sand paper and brush any dirt and grime out of the area. I recommend going to your nearest Radio Shack and buying the De-Oxit kit to clean these. These two grounds caused numerous running issues for me, especially the LH ground which I had found loose.

On a side note, the LH ground on the bellhousing, passenger side also grounds the oxygen sensor loop. Bad grounding of this connector also causes massive richness at idle and cruise.
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Old May 20, 2013 | 11:23 PM
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Hi Jetdriver,

Google search works extremely well with Rennlist-

Use this link:
http://www.google.com/search?client=safari&rls=en&q=site:forums.rennlist.com+inurl:928
If you add search terms, such as "ground points" afterwards, you will find tons of responses.

I only say this because I find the search function within the site to be less good.
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Old May 20, 2013 | 11:38 PM
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Default Ground

87s4. This could be my problem....I don't have a ground for maf o2 etc that goes on mp ix...I know that bolt but my harness did not have an eyelet for it...

Maybe I missed it in reassembly after engine install....

On my harness I had only 2 eyelets for ground which I assume was fuel injector grounds....if anyone has pics of the passenger side grounds would be helpful...

If for some reason I don't have the ground eyelet, do I make one?
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Old May 20, 2013 | 11:42 PM
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Did you read the "New Visitor?" sticky?

Post #33 (page 3) has the ground points diagram and links to some very good pictures.
In fact, that whole thread is filled with stuff.

It saved me from asking a lot of very obvious questions when I first got my shark.
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Old May 21, 2013 | 12:08 AM
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I looked at sticky carefully...there is a pic of viii and ix...on ix it just shows a clamp on the bolt...is that the ground for the harness? I do not see an eyelet for ground..

My question is how is the maf lh o2 sensor grounded? Is it just this clamp or is there a ground eyelet like the fuel injectors?
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Old May 21, 2013 | 12:27 AM
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You have to take off the fuel pressure regulator to see it.
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Old May 21, 2013 | 12:29 AM
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Originally Posted by newworld
I looked at sticky carefully...there is a pic of viii and ix...on ix it just shows a clamp on the bolt...is that the ground for the harness? I do not see an eyelet for ground..

My question is how is the maf lh o2 sensor grounded? Is it just this clamp or is there a ground eyelet like the fuel injectors?
newworld, the pic of the the bell house grounds was really just for location. You are correct in that there are no grounds attached to them.

And, not all the grounds attached to them are eyelets. This is from experience.
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Old May 21, 2013 | 12:33 AM
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LH, O2, and MAF are grounded to the same single eyelet.
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Old May 21, 2013 | 12:38 AM
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Originally Posted by Mongo
LH, O2, and MAF are grounded to the same single eyelet.
Sorry Mongo, you're right. The non eyelet attachment I was speaking of was on to MP VIII from memory.
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Old May 21, 2013 | 12:48 AM
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New visitor stuff is old and spotty, needs refresh.
It's one resource.


There are some closeups within this that will help, but don't fully answer the question:

http://www.dwaynesgarage.norcal928.o...%20Refresh.htm


All grounds have ring terminals.

At VIII on S4 you will find a ring terminal grounding LH terminal 17 & shield for O2 sensor.

At IX , ground wire for MAF, for Code plug, for TPS, for test plug & terminal 18 of EZK.

Go to 87 wiring diagram for engine compartment and you will see this clearly.
(get the CD's from Roger with the full set of manuals and extensive additional documentation -- hard to operate without that particular set of docs)
There are also some grounds that don't appear on the wiring diagrams, such as at coil clamps and at wiper motor.
That is because they are for radio interference suppression.
There is also a ground way up under the passenger dash where the windshield amplifier box is mounted.


There are layers of stuff down there under the air cleaner, partially ocluded with wire clamps for hall sensor wires and harness, etc.

Maybe use Dwayne's pictures and compare to yours.


Not sure your car's history, but its pretty important to address fuel lines properly. Its one of those layers that need to be dealt with. You have some choices, please replace them properly before driving, especially since you are in there digging around! its covered in Dwayne's attached link. There are new options for fuel lines from Greg at Precision since Dwaynes piece was written. Too many of these cars have succumbed to flame.
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Last edited by Landseer; May 21, 2013 at 01:22 AM.
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