When the car is warmed up and i'm at a stoplight i can feel the car start to miss. I changed plugs, wires, fuel filter, about 8 months ago. I checked them the other day and they look ok..no burned wires. I also keep getting the ABS Inop light here and there. My batter gauge will read under the middle line as well. Is this a sign of the opti going out? Thanks for any replies!!!!

 

Check your 02s. After you are in closed loop, your 02s come online and that's when you might get a faulty reading from them causing your miss.

 

The "batter gauge" (aka volt meter) being "under the middle line" is not a sign of the Opti going out.

 

So I might just have a faulty "battery" then? Today, I ran the car around town and came home and put a voltmeter on the battery while the car was running with all accessories...a/c, stereo and got 13.6V DC. With the car off I get 12.4V DC....does this sound low?

 

My 94 did the same thing A B S light and all it was just the altonater

 

You voltage sounds just fine.
Sounds like a spark issue to me.
Listen for arcing under the hood at idle. I've had a couple spark plug's insulators crack, allowing it to spark to the head. Also check the high voltage coil wire's connections...

If it's random spark misfire related, your rpm will stay pretty constant, just a blip here and there.
If it's closed loop fueing related (o2's), your rpm's might vary greatly as it 'chases its own tail' trying to keep itself alive (i.e. vacuum leak, check for them!).

 

Thanks for the info. My rpms stay pretty constant at idle. It just starts missing when it's been driven for a while(30min or more). I'll look to see if any of my spark plugs are arching tonight...how can i tell if it's arching? BTW the spark plugs are Autolite Double Platinum and my wires are 8mm Taylors.

 

if it's arcing, you'll be able to see it at night

 

If it's arcing you'll hear it, or see it if its realllly dark. Also the stock closed-loop timer is set to around 200 seconds, so if the problem doesnt manifest itself then and only 30 minutes later, it may not be directly closed loop related.

How bad is the miss?

 

Consider the possibility of problems with components that "heat soak". Two of them are the IC Module, and the optical sensor in the Opti. Injectors can also heat soak.

 

check what everyone else said, but i had the same thing last month. i fixed it by pulling the intake and spraying out the throttle body with throttle body cleaner w/ the blades opened, engine off. i used the blue and wht valvoline can sprayed it all around in all corners and into the ports.

i drove the car for 20 min before doing it. hot engine is better. i also did the water treatment. put hot water in a spray bottle, left it in the sun for the 20 min and shot that right into the throttle body too with the engine running and revving by hand around 2500-2800 i think. don't let the engine die. finished with more throttle body cleaner. i used a little over half the can

also sprayed the MAF wires down with electronic parts cleaner. rough idle smoothed right out. i also ran half a bottle of Redline SI-1 in the tank for a few days before doing it. still running smooth

 

I checked last night and no "light show" under the hood. My throttle body is cleaned out every 6 months or so with seafoam spray. I cleaned my MAF with alcohol when I last did my K&N Filter. I'm still getting that miss when the engine is hot. I checked all my plugs on the driver side and they all are gapped correctly and look good. I really don't want to pull my plugs on the passenger side...such a PITA!!! I did realize that my plug wires were touching each other but i fixed that. I think I might just replace my opti anyways...it's been on the car since i've bought it 40000 miles ago and I think it might be the original. Thanks for the suggestions guys!!

 

Sorry i cant offer any advice but i have had a random slight stumble ever since i bought my car! Even after having the engine rebuilt and replacing all the sensor's and such it's still there..lol I figure i will wait until it gets worse and easier to find!