I've had some electrical issues that have been happening (now that I've identified it as an electrical issue) over the past few months, and I'm curious as to what the community thinks it is.

What has been happening:

The longest running issue has been an engine stumble that has been happening very intermittently over the past few months that comes on when using partial throttle below 2000 RPM. I first noticed it on the highway in 6th, when I went to give it a little gas and the engine stumbled a bit, so i dropped a gear and got the revs up and it went away. This continued to happen every once in a while, all under the same circumstances of below 2k RPM and partial throttle. (It should be noted that the car has a larger cam, FAST 90mm manifold/TB, callaway honker intake, LG long tubes, random tech xpipe/hiflow cats, callaway exhaust, patriot heads)

I checked all vacuum lines and everything looked good, was thinking it maybe needed new plugs/wires or the MAF cleaned, and the issue didn't happen very frequently so it wasn't super high on my priority list. Also, the DIC was not showing any codes at all, even when checking before shutting the car off after these stumbles were happening. Further, the check engine light did not flash when the stumble occurred.

Then, a couple of weeks ago, my amps (2 of them, a JL 300/4 powering 2 sets of Boston Acoustics components, and a JL 500/1 powering a JL 10W3v3) started cutting out at the same time at about 60% volume, which had never happened before (i've had the car since june). Using a digital multimeter I found that they were cutting out because of a voltage drop to protect the amps, with a measurement of 12.5 at the battery and 11.6 at the amps, and then when i turned the volume up a little to cause the amps to cut out I was measuring a drop in the 9's. I tore out parts of the interior to check the ground wire connection, and found that the installer ran the grounds all the way back to the battery, probably to ensure the lack of a ground loop, and everything appeared to be fine. I might try running new grounds to the seat bolts just to see if the shorter ground wires help alleviate the voltage drops. I also have a Big 3 kit from southerncarparts installed, and everything is tightly connected there.

This new amplifier issue made me think the engine stumbling is related, so I had the alternator and battery tested at autozone, and everything checked out fine. I had previously installed that Big 3 kit because my headlights would dim on bass hits, but that issue did not go away with the installation of the Big 3, for whatever that's worth. The car does have some of the LED taillights on it that do occasionally have hyperflash issues (my old '04z had the same lights without this issue, so i guess it's completely random), in case that could contribute to anything.

Then, a few days ago i was enjoying the cold weather, decided to get on it from a stop and the car stumbled and then backfired on me, which was new.

2 days after that (last tues) I had to go to the airport for thanksgiving, and all was well until I pulled into the crazy traffic at hobby airport, and the DIC gave me a LOW OIL PRESSURE message with the gauge at zero, as well as a very rough idle with the car acting like it wanted to die. The oil pressure gauge quickly came back, and I assumed the voltage issue caused the problem and that the oil was fine, and that the idle issue was caused by the car cutting the fuel when it detected the pressure issue. I had to ride the clutch a bit to keep the car alive and into a parking spot, and when i returned last night I was happy to find the car was fine on oil and it started fine and got me back home.

This morning I ordered new plugs/wires, as well as a new ignition switch to cover all of those bases.

Am I on the right track? Does anyone have any other insight as to what I should be looking at/for?

Thanks!

Pat

 

10-4, I'll check the voltage at the battery tomorrow night after my hockey game as I have a solid 30 min drive on the highway both ways as compared to the little 5 minute jaunts to work and back that probably don't charge the battery much...

And I'll follow the diagnostic plan to see if there's a drop in voltage at one of the ACC/ON fuses as directed in the diagnostic post.

Are these symptoms indicative of an ignition switch though? I know that little bastard can cause a wide range of problems, I just haven't found anyone on this forum that has the same problems that I've described...

Thanks again!

 

There are FIVE different ignition contacts inside the switch and only four are used. The more the switch is worn. corroded/ burnt, the LES current and voltage it will conduct.

On that note, there are NUMEROUS relays, and fuses that also need to have good contact and [pass the correct CURRENT and VOLTAGE.

I do suspect that you could gave an ignition switch issue BUT, you also need to CAREFULLY INSPECT the two harness connector plugs that plug into the ignition switch. Look for damaged/spread apart female pins, Melted connector female pin cells, etc...

The BEST and most precise way to figure out if the female pin is good is to conduct a PIN PULL TEST on each female pin..

Once you replace the ignition switch, If you STILL have issues, you will need to trouble ONE issue at a time by checking/monitoring the power/ground on that circuit..

Bill

 

The large pins on the black connector were spread apart significantly!

 

I will definitely check that out as well, and thinking about this, I had the center console/radio bezel off right before these issues started getting worse to install a short shift kit, so there's a good chance the aftermarket stereo wiring was pushed into the ignition switch, causing an improper contact that could have accelerated the problems....

The new switch will get here on Weds along with the plugs/wires, so i'll have a busy evening and hopefully we're on the money.

Thanks!

 

I think you have two issues. The problem with the supply voltage to the amps is separate from the engine stumbling.

With everything turned off what is the voltage at the battery? Voltage at the amp? There should be less than .2 volt difference.
What is the voltage at the battery with the engine on? Voltage at the amp? Again there should be less than .2 volt difference between the readings.
If there is more (the info posted indicated .9v) look into the connectors on both ends. Most likely there are bad connections at one end. Also what gauge wire is being used for the feeds. The JL 500/1 amp alone should require a 4 gauge power wire. I would not be surprised if the 300/4 also required a 4 gauge power wire. If there is one feed from the battery to a distribution block at the amps it should be a 1/0 gauge.
Also where is the amp power wire connected to at the battery end, the battery or under hood fuse box input terminal? Where is the ground wire connected? This wire has to be the same gauge as the power wire.

Now for the trick question, what year do you have? Up to around 2002-2003 there was a pigtail in the passenger foot well for powering aftermarket equipment (switched, constant and ground). This was not included in 2004's. Some installers did not know about this and would tap off of the ignition switch wires. If this was done then that could be a source of other electrical issues.

Let us know what you find.

Gary

 

You could run the car with the amps off fuse/power and see if car stumbles then. This way you know if related or not

 

The car is a 2004.

Looks like the battery might be dead.

Voltage at the battery: 12.16
Voltage at the amps: 12.12

Voltage at the battery with the car on: 14.52
Voltage at the amps with the car on: 14.47

Both amps are connected via 4 gauge wires, and both have their own feed off of the battery. The ground wires are also 4 gauge and are fed from the battery.

I also think i found one of the issues:

and a few of the other wires look similar, so the new plugs/wires that arrive tomorrow can't come fast enough...

 

I have only done this to the extent that I had everything powered off (hadn't done anything special in regards to disconnecting anything) and still experienced the stumble... I'm guessing the deteriorating plug wires are one-of-if-not-THE main issue at play here, as well as the Optima Red Top that is apparently on its last legs.

It's also my understanding that Red Tops are not ideal for applications where there's an aftermarket car audio setup?

 

Update:

Installed an Optima Yellow Top battery last night and pulled the old Red Top (6/13 manuf. date), finally got around to installing the Hurst short shifter that i picked up a couple of months back, and installed the new ignition switch. Did not get around to installing the plugs/wires as my back started to make me feel old, so I'll be tackling that tonight.

The ignition switch that I removed absolutely had some burnt contacts (I'll try to remember to take/post pictures tonight), and I'll be cleaning it up to hold as a spare for when the new one exhibits similar issues down the line. Once I pulled the old one I realized that there really was no need to install a new one as it's an easy fix, but I don't regret it at all for the peace of mind coupled with the fact that the new one has tightened up the operation of the locking cylinder, which feels nice. Unfortunately, it did not fix the RFA NO COMM problem that the car has had since I bought it in May, so it looks like I'll be using my MM to test the power source at the unit in the back, and my bet is the wire got crimped somewhere and I'll have to run a new one to an "always on" lead in the passenger kickpanel in order to get it operational again.

Got everything buttoned up and tested it out, and the amplifiers are working as they're supposed to with no cutouts, so all is well on that front again, which is great!

Now that I've seen the condition of the plug wires, I'll be surprised if the stumbling issue isn't resolved after tonight's install, so it looks like we'll be running like new again.

Thanks for all of the help to get me this far, everyone!

 

Just finished the test drive after getting the plugs done, and it appears everything is perfect; from a SOTP perspective it's running far better than at any point before.

Here is an album to pictures of each of the spark plugs as well as the contacts of the ignition switch; any thoughts on the condition of the plugs? Looks to me like a few of them show rich conditions, no?

I'm curious to see if my gas mileage improves as it dropped off once the issues started occurring.

http://imgur.com/gallery/hXpkX

 

http://www.4secondsflat.com/Spark_plug_reading.html

 

ha, i read that site (and a few others) maybe an hour before you posted it. Just curious as to what others think about them.

 

what other sites did you find?

 

In my experience, once you start cleaning them you have to reclean them about once a year. After the third cleaning of mine, I gave up on it and just got a new one. The original unit went 12 years before it needed cleaning. I'm OK with replacing parts on that schedule.

 

Some of those gaps look WAY big, and it also looks like someone has already been in there and tweaked on the electrodes judging by the angles. Your burn condition looks fine all things considered. The plugs with the gaps farther out are going to tend to pick up more carbon.