misfire, no codes

[IICODECll]

As per Blizzard242 suggestion:

Yesterday being beautiful out I made sure the car started fine for the daily ride to work, filled my tires up with air to the required 44 psi, and boom, misfire while halfway down to work. Then another, and another. No check engine light flashed. Punched my way through it, went away. Then the RPM range was starting to get funky: 2500 at 55 mph, then it fell back down a few minutes later to ~1800 in Drive. Did that at least twice for the whole ride to work (44 miles). [rebuilt transmission with < 16,000 miles on it]

The only other time you heard it was when it started up from a cold start. Put it in drive, stepped on the gas, and it worked itself out a few seconds later.

I replaced one coil pack about 3 - 4 weeks ago, and had a tune up done at the same time. Replaced spark plugs with double platinum plugs. (mechanics said it was better.). It sounded great no more annoying tick. Now there is a slight ticking sound again from the left right side behind the alternator. Oil levels are fine, and tranny fluid is still red/pinkish. Any ideas since there are no codes?

From the looks of it, the 1/4 coil pack is the only original one on the car (120,555 miles) all the way in the back. I can't get it out because my extender is about 1/2" too long, and hits the frame. I replaced one pack, but still have the same random misfire every so often since last night.

[ssms5411]

Re: misfire, no codes

I wouldn't run your tires at 44psi that is max psi, they have no room to expand if they get warm(your going to warp your tires). I would say run them at 35 psi. I would check the coil packs first before replacing them.

[IICODECll]

Re: misfire, no codes

I think I filled them up for 39/40, since the left-rear tire keeps loosing area, even after putting a new tire on it, and all the little accessories. It was about 20 psi when I filled it up (don't drive much outside of work). Anyway, how do I check them? The one I just took out looks burnt on the edges. The wire looks fine.

[ssms5411]

Re: misfire, no codes

You can use a OHM meter to check the top posts and the bottom.

[grayman]

Re: misfire, no codes

no matter how expensive the spark plug wires are they all seem to have a chance for the ends to loosen over time or especialy with repeated removal fromt the spark plug or coil. some wires can also be tricky and SEEM like they are on tight. suggest taking a look at the fitment of the ends of the spark plug wires. also suggest taking a look at the condition of the wires them selves. look for cracks in the insulator. go out at night with the hood up and turn off all exterior lighting. start the car and look for arcing from the spark plug wires.

[IICODECll]

Re: misfire, no codes

Aw man, too bad I just graduated college, otherwise I'd go back to the Physics building and steal one of those OHM meters. :)

From what I can tell the wires are fairly new. Put on just before I bought the car. The ends/boots look fine, no cracks in them. They are clean on the inside. I'll try looking at them tonight when I get out from work at midnight (perfect timing, eh?).

Why is it they designed everything to be half-assed when it comes to coils and the spark plugs? Just one thing I noticed when my father was telling me to change the plugs a while back until he finally noticed where they were located.

Thanks ssms and grayman =]

[IICODECll]

Re: misfire, no codes

Okay, I finally got coil pack 1/4 off, one of the plugs was completely rusted out on the coil pack. The wire leading to the plug was also completely rusted out on the inside. So, now, new wires it is. It's now flashing a SES light (sometimes staying solid) with code P0300 Multiple/Random Misfires (x2 codes). The car sounds like ubber crap now, lol.

While I was out there working on it with someone, I moved one of the wires over and I got such a shock to hell. It went up my arm and down the other. I nearly felt like I had a heart attack.

I made sure the order of the wires were right. I'm almost 99% sure of that.