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Funracer
06-13-2012, 04:13 AM
Anyone have a list of grounds? Good description
of location would be very helpful. The only one I know about is
behind the battery. Looking particularly for anything that might
affect driveability under 3000 RPM.

Thanks

PS. I did a search. Now looking for ECM grounds (behind the battery?),
alternator ground and anything else you got

Thanks again

Paul Workman
06-13-2012, 05:56 AM
Anyone have a list of grounds? Good description
of location would be very helpful. The only one I know about is
behind the battery. Looking particularly for anything that might
affect driveability under 3000 RPM.

Thanks

PS. I did a search. Now looking for ECM grounds (behind the battery?),
alternator ground and anything else you got

Thanks again

An FSM is a "must have", but most of the electronics - including the ECM - are grounded on two lugs on the block either side of center, just above the top edge of the bellhousing. The battery neutral is grounded on its own lug on the side of the block. Other sundry items are tied to the frame.

P.

Paul in VA
06-13-2012, 07:38 AM
My terrible grounding experience was the bolt Paul (above) talked about. My loose bolt was on the back of the engine, passenger's side, just above and very close to the bellhousing bolts. Mine was loose (not missing; accidentally loosened when pulling trans and not noticed) and made my car run terrible under 3K. Over 3 K it ran, but not nearly as good. Jim Voter (WAZOO) was able to tighten that bolt with the car on a lift and using a bunch of extensions and inginuity (Thanks Jim!). Once tightened, everything went back to running perfect, just like a switch was thrown. Good Luck!

scottfab
06-13-2012, 09:04 AM
Ah yes the much feared intermittent lose of ground at the bell housing.
This is not just a loose bolt phenomenon.
It's most insidious form of failure is corrosion. The ground develops a low resistance value which then develops a variable voltage drop which is a function of current draw by other accessories sharing that ground.
This is a well visited issue over the years.
The cure is light sanding of all the lug surfaces (front and back) as well as the area around the bolt hole. Then a coat of dielectric grease to prevent oxidation in the future. This preventative measure is well worth doing to both bolts at the top of the bell housing if your not sure it's been done on your car.

Funracer
06-13-2012, 01:47 PM
My terrible grounding experience was the bolt Paul (above) talked about. My loose bolt was on the back of the engine, passenger's side, just above and very close to the bellhousing bolts. Mine was loose (not missing; accidentally loosened when pulling trans and not noticed) and made my car run terrible under 3K. Over 3 K it ran, but not nearly as good. Jim Voter (WAZOO) was able to tighten that bolt with the car on a lift and using a bunch of extensions and inginuity (Thanks Jim!). Once tightened, everything went back to running perfect, just like a switch was thrown. Good Luck!

That sounds a lot like my issues. Will try to figure out how to get
at these grounds and report back.

I do have an FSM. Used it so many times over the years it is falling apart.
I know it points out grounds throughout the manual but I thought someone might have made a list since it seems to be an ongoing issue
as these cars age.

Regards

scottfab
06-14-2012, 01:54 AM
That sounds a lot like my issues. Will try to figure out how to get
at these grounds and report back.


With the plenum off you can just get at them from the top.
Else from under using various "wabblies" and extensions.

Funracer
06-16-2012, 02:53 AM
With the plenum off you can just get at them from the top.
Else from under using various "wabblies" and extensions.

Thanks. Kind of bummed because I just put the plenum
back on last weekend and pretty much swore I would never
pull it off again unless I dropped the wifes diamond ring down there.

I guess its the "from underneath..." option then.

Paul Workman
06-16-2012, 05:59 AM
R&R'ing those connections - would make sense to add that item to the "while I'm in there" list whenever changing the clutch. With the trans and bell housing off, the bolts and lugs are totally exposed to a simple socket and ratchet combo.

Often when working on stuff, one of those flexible "universal joint" links come in handy. But, in instances like this one, where you have to poke a socket waaaay in where you can't reach, those flexible links are too floppy and the socket on the end flops down and getting/keeping the socket on the bolt is frustrating, especially if you have multiple extensions involved!:-x

Well, I may be the last one on this site to discover this, but wrapping those "U-joint" links with a couple wraps of masking tape - allows the joint to flex, but it is now stiff enough that the socket hanging on the end stays in position to engage the bolt head. If you have to go "down under" to get to those ground lug bolts, the masking tape on the U-joint might help you keep your sanity!

:cheers:

P.

scottfab
06-16-2012, 10:52 AM
Well, I may be the last one on this site to discover this, but wrapping those "U-joint" links with a couple wraps of masking tape - allows the joint to flex, but it is now stiff enough that the socket hanging on the end stays in position to engage the bolt head. If you have to go "down under" to get to those ground lug bolts, the masking tape on the U-joint might help you keep your sanity!
P.

Or you can buy a few short "wobbly" extensions. (1 in).
Works great because they don't flop over at 90deg.
The most they move is about 10deg.