edrrt

190k miles. Runs like a top. Recent new plugs, cap, rotor. Recently clean the throttle body. Drove accross the country without a problem then in the last few miles of the trip had to turn it off on the freeway for stopped traffic from an accident.

Upon restarting I noticed that it sounded as though it was intermittently missing. Revving the engine did not solve the problem and the car seemed to have no power. Throttle response seems normal.

After approximately 30 seconds the engine ran as normal.

I stopped and restarted two more times in traffic. Each time the intermittent misfire seemed to be there and then it would resolve itself after about 30 seconds. After the second time this happened the check engine light illuminated. It indicated random cylinder misfire and misfire codes for cylinders 1 through 3 every single time.

After passing the accident and resuming normal driving it is never occurred again. The next day the check engine light had cleared itself.

I am concerned something is brewing.

Does this sound like an oxygen sensor might be going out? Carboning of the valves? The crankshaft position sensor?

tjwalker

It's possible you could be on the front end of a fuel pump issue. I'd start by verifying pressure. For your 99, you should have 49 psi, plus or minus 5 psi.

Lots of other possibilities, but testing fuel is easy schmeezy and should be done first.

CCKen

edrrt,


What brand/type spark plugs did you install?

edrrt

NGK V-Power. If it was a spark plug problem I would think it would be odd for it to occur on all three plugs the same time? Especially when it was running so well.

edrrt

when it was having the misfire though it would accelerate very responsively and just fine while still having the misfire on what felt like just one cylinder. If it was a fuel starvation issue I would think when I stepped on the gas it wouldn't rev up very well.

tjwalker

Don't assume anything.

Testing is the only accurate way to determine root cause. And starting with fuel pressure is what any technician worth their salt would do early in the process if you brought it into their garage.

I am not saying that is your problem. But I am saying that it needs to be ruled in or out. Testing wins out every time over hunches or gut feel.

Oftentimes, the biggest part of finding out what your problem is? Is finding out what it is NOT.