Cleaning/checking grounds

**Titus** · 04-13-2006, 12:50 PM

I upgraded my car to a 4-wire O2 sensor a few weeks ago, which required tapping in to 2 of the car's ground points. Yesterday, I started noticing erratic O2 sensor reading on my Air/Fuel gauge. I checked to see if the ECU was throwing any codes, figuring that if the ECU was happy, the problem would be with the gauge. The ECU was actually throwing a 3, which is engine ground. So how do I go about checking the ground points and cleaning them up? Anything I can look for? Do I just need to rough them up with a wire brush? Should I put some of that dialectic goop on them?

**riverracer** · 04-14-2006, 12:05 AM

If trying to make it better ....causes more problems...Why don't you leave it alone and drive it? You need to get out more....

Like Saturday with the S2K bunch?

**onething** · 04-14-2006, 06:26 AM

I'd start with the obvious. Put riverracer's right hand on the block and tell him to hold a plug wire in his left

while you start the car. It has been my observation in the past that shock therapy for the smart

usually relieves tension and helps you think more clearly.

Look at all the connections you made. Are they tight? There should be at least one connecting strap from the engine and one from the battery (neg) to the car body. Check them all for tightness and corrosion. What about the ECU - does it ground to the car at the module (I don't know)?

**riverracer** · 04-14-2006, 06:37 AM

I think onething has a good point! What time do you need me to be there?

**POS Racing** · 04-14-2006, 07:19 AM

I'd double check your new work and make sure you don't have a loose connection.

Then you you can pull the grounds and clean them and put them back a touch of Dielectric grease never hurts.

IIRC there was a section in the enthusiast manual about the grounds and how to check them, ya may want to review that.

**Titus** · 04-14-2006, 07:55 AM

Originally Posted by POS Racing

I'd double check your new work and make sure you don't have a loose connection.

Then you you can pull the grounds and clean them and put them back a touch of Dielectric grease never hurts.

IIRC there was a section in the enthusiast manual about the grounds and how to check them, ya may want to review that.

Well, the ground strap between the body and the block looks like

, covered in grime. I took it off on the engine side to slip a ring terminal for the O2 Sensor on the bolt and wiped it off a little, but I didn't really do much else to it. I might be better off replacing it with a new one, but I want to try and clean this one up first. I was thinking I could take it completely off and soak it in something for a while (maybe Carb cleaner or CLR?), scrub the metal warts with a wire brush, re-crimp the ends, and then put it back on with some Dielectric grease. Thoughts?

I would look it up in my enthusiast manual if it was in my possession.

I put the 4-wire O2 sensor on because it is a requirement of the LINK ECU I will be adding shortly in an attempt to find another 20 HP. I planned on ordering the ECU this week, but have postponed the order until this issue is resolved.

**tailchaser** · 04-14-2006, 08:00 AM

So you took it off on the engine side and wiped it a little... The Great Carnac says... There's your problem!!!

Whatever you touched last is almost always where the problem is.

**POS Racing** · 04-14-2006, 08:01 AM

Originally Posted by Titus

Well, the ground strap between the body and the block looks like

, covered in grime. I took it off on the engine side to slip a ring terminal for the O2 Sensor on the bolt and wiped it off a little, but I didn't really do much else to it. I might be better off replacing it with a new one, but I want to try and clean this one up first. I was thinking I could take it completely off and soak it in something for a while (maybe Carb cleaner or CLR?), scrub the metal warts with a wire brush, re-crimp the ends, and then put it back on with some Dielectric grease. Thoughts?

Sounds like a plan I'd try carb cleaner, it's been a while since I cleaned the grounds on the old NA I had but IIRC isn't there a ground near the starter also? As well as the one from the block to the firewall??

Originally Posted by Titus

I would look it up in my enthusiast manual if it was in my possession.

You should get yourself one, I used the heck out of it, along with the Factory manual. Then I sold it for more than I paid for it on Ebay!

**Treibenschnell** · 04-14-2006, 10:00 AM

Originally Posted by Titus

I would look it up in my enthusiast manual if it was in my possession.

So when is CM gonna give it back?

You can borrow mine if you'd like.

**channelmaniac** · 04-14-2006, 10:14 AM

I sent him a PM asking for shipping info so I can have Moss send him one. Order is keyed up & ready to submit.

It's the least I could do after keeping his so long & getting some greasy thumb prints on it.

RJ

**Treibenschnell** · 04-14-2006, 10:16 AM

Originally Posted by channelmaniac

...some greasy thumb prints on it.

RJ

How appro for Titus!

**Titus** · 04-14-2006, 11:24 AM

Originally Posted by channelmaniac

I sent him a PM asking for shipping info so I can have Moss send him one. Order is keyed up & ready to submit.

It's the least I could do after keeping his so long & getting some greasy thumb prints on it.

RJ

**BAM!** · 04-14-2006, 10:11 PM

one of the grounds not mentioned is the one connected to the ppf. i dont think thatd throw a code though.....

**channelmaniac** · 04-15-2006, 06:45 AM

Make sure to clean & check the ground wire off the back near the CAS and then take off, check, and clean the grounds under the master brake cylinder. That one is usually pretty nasty after all these years.

RJ

**POS Racing** · 04-17-2006, 08:45 AM

Well did ya fix it Sparky?

**Titus** · 04-17-2006, 08:46 AM

I removed, cleaned, re-crimped, and re-attached (with dialectic grease) the ground strap by the dip stick and the grounds under the master cylinder. It seemed to improve the issue I was having for a while, but it came back after about 10 miles.

I then picked up a new ground strap from Walmart for $2 and ran it from the body to the intake manifold. 100 miles since and no AF/R meter issues and no ground CEL.

**Titus** · 04-17-2006, 08:56 AM

I should add that I will be cleaning all of the other ground points as soon as I have my new enthusiast manual to help me find them, and then I will be replacing my 1 TCB Walmart strap with the 6 ground wires in this kit. You may laugh and call it rice (as I did), but you might just be singing a different tune if you ever run into intermittent ground problems. I am told that aftermarket ECUs are particular about the quality of their ground, so I'm not taking any chances.

**channelmaniac** · 04-17-2006, 10:22 AM

Originally Posted by Titus

I should add that I will be cleaning all of the other ground points as soon as I have my new enthusiast manual to help me find them, and then I will be replacing my 1 TCB Walmart strap with the 6 ground wires in this kit. You may laugh and call it rice (as I did), but you might just be singing a different tune if you ever run into intermittent ground problems. I am told that aftermarket ECUs are particular about the quality of their ground, so I'm not taking any chances.

When you get that kit in, can you measure those wires? It'd be cake to get some braided ground wire & replicate that.

RJ

**Treibenschnell** · 04-17-2006, 10:36 AM

Originally Posted by Titus

...f you ever run into intermittent ground problems...

I'm currently dealing with those in the VW so I feel your pain!

**Titus** · 04-17-2006, 11:08 AM

Well, Leni just emailed me and it looks like he is all out of the 90-93 kit, and it was a one time purchase.

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