Low Idle after wiring upgrade

[Jayson]

Hey guys, I'm starting the Big Three and I just recently upgraded the battery to chassis ground with 1/0 gauge wire. I haven't done the alternator to battery or block to chassis ground yet.

After upgrading I noticed the idle on my car seems sketchy, and it drops when I shift (A/T), mainly on Reverse, Neutral, and Park. I was wondering if this could have anything to do with me only upgrading one wire; could it be bottle-necking or something?

I've also read about the IACV being responsible for the idle, but the reason I suspect the wiring is due to the problem arising shortly after I install new battery terminals and upgrading that one ground.

The car still runs so I don't know how serious this is but it doesn't seem "healthy" and I can't just let it go. Does anyone have any suggestions?

P.S. I've already thrown away the stock bat-chassis ground and battery terminal ring and put the stock tranny ground into the aftermarket terminal, so I can't troubleshoot by swapping it back to stock to see if it helps the problem.

 

[Bax]

The only thing you are doing with this upgrade is providing electrons with a larger/better path. I honestly didn't notice one difference besides startup being like a second quicker. I still think it may just be the placebo effect though.

Look at my member's ride page, I did my chassis-battery, block-chassis, and battery-tranny wires and car still runs the same for me.

Upgrade the tranny-battery wire and see if that helps anything.

 

[ryan s]

have the car running at operating temp, turn on the headlights and A/C, then shift and see if the idle dips or not.

 

[Jayson]

It seems really inconsistent, after I got off work today the opposite happened. Now it seems to be idling high (a little over 1000 rpms) and that was with A/C full blast and headlights on. It did end up going back right below 1000 rpms in Park when I got home.

 

[Bax]

finish the grounding upgrade.

 

[ryan s]

measure the resistance of the grounding point, then measure the voltage of that point with the car running. heck, measure the resistance of the wire itself just to be sure (wire does corrode and break down internally, after all).

it really sounds like a voltage regulation issue...that is, increased resistance at the one ground you've "upgraded" is leading the ECU/ELD to go crazy. that it idles higher than normal with the A/C and headlights on would lead me in that direction.

since it only started after messing with the ground and the terminals, well, there's your problem in there somewhere. bad connection, bad wire, bad termination, inadequate bare metal at the ground point, poor plating on any terminal/ring terminal, loose connections, etc...

its quite fruitless to upgrade the rest of the wiring when one ground is causing an issue. that issue will continue, especially if the stock wiring was not hindering the electrical system.

 

[CG6Lemon]

Did you properly clamp and hammer the terminal tight enough so you can't pull the wires off of it?

 

[Jayson]

Well, I just redid the ring terminal where the battery to chassis ground is, this time I soldered it to a quality ring terminal using a propane torch, silver bearing solder and flux. The problem remains. I also upgraded the block to chassis ground to see if that helps, also with soldered ring terminals.

Now the car literally almost stalled after I started it and watched it for a minute, then idled under 1000 with little dips here and there when shifting. Seriously, my car is not running like a champ right now and I'm getting frustrated. All I did was increase the wire gauge how is this even possible?

@ryan_s I noticed you mentioned inadequate bare metal at the grounding point. I had already sanded that point down with 220 grit sandpaper and it appears to be bare metal. As for the resistance, I have a multimeter but I'm not sure how I would do that.

I hope someone can shed some light on this. I wasn't expecting a noticeable increase in performance by doing this upgrade but I sure the hell didn't expect the performance to diminish...

 

[Bax]

Exactly what type of wire did you buy? and what terminals? links maybe? Sounds like you got ahold of some crap stuff possibly.

And your multimeter should have an ohm selection on it. That would be the resistance.

 

[gokblok]

The only thing you are doing with this upgrade is providing electrons with a larger/better path. I honestly didn't notice one difference besides startup being like a second quicker. I still think it may just be the placebo effect though.

Look at my member's ride page, I did my chassis-battery, block-chassis, and battery-tranny wires and car still runs the same for me.

Upgrade the tranny-battery wire and see if that helps anything.

"The Big 3" is really mostly an upgrade for accessory power draw, such as high power amplifiers for a stereo system. Shouldn't really improve anything with the ignition system, as the whole system was designed to run on 4ga or smaller wires all around.

But if you don't make sure all your connections are super clean, the Big 3 could be more of a hindrance, because you've upset pathways that were otherwise uninhibited. Bad connections are NOT to be overlooked. Good crimps on your connectors, if not solder, and heat-shrink are indispensable.

Good luck.