Random misfire issue Fuel? Ignition?
Moderator: volvite
Random misfire issue Fuel? Ignition?
Did a tune up on my 99, ran awesome for few days. All the sudden, its lunging down the road. Scam didn't give me much to go on. My gut tells me fuel issue. Althoug a bad 02 sensor came up. But I've never had 02 cause a misfire of this caliber. This thing is right at 170k, I'd think if I got bad plug wires it would have been evident right away. Please, any tips..Thanks
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volvite
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I agree with smj on the spark plugs. I've seen this time and time again when I used to work at autozone and everyone wanted the bosch plugs when their vehicle recommended something else. Best example for me was mopar in particular Jeep. They used the champion cooper core plugs but everyone wanted the bosch. I told them I'd see them back in a few days when they discovered their vehicle ran worse than before the tune up.
Stick with OEM brand plugs. Not that you have to buy them from the dealership.
Stick with OEM brand plugs. Not that you have to buy them from the dealership.
I did use NGK. And matching ignition parts. Not to say I couldn't have gotten a lemon. The car is throwing an 02 sensor code. Is it possible a bad 02 sensor can affect the firing this much?Just never saw this on previous cars. On that note, is Bank 1 drivers or pass side? getting conflicting info. I'll start with that and work my way through the list. Ideas appreciated
Bank #1 is the bank that begins with cylinder #1, which would be the right side or passenger side of the vehicle on the VG engine. If the code was for a front O2 sensor, it could be that the sensor is causing a lean condition thus resulting in a misfire. A rear O2 sensor failure would not affect the way the engine runs; it's only for monitoring purposes.
02 sensor not the issue. But the SES light did go away. Car ran great til it warmed up then went back to shuttering. Being warm definitely makes this worse. Anyway, I'm not ruling out firing issue(s) but think it would be more like distributor or timing belt. Pulled Dist cap off, did not seem to be sloppy. Any ideas what to check next? I planned on searching for a fuel filter and possible replacing fuel pressure switch. Open to ideas here.
Mystery may be solved
took the girl to my local mechanic. After 4 days he calls and says "I don't know for sure, but bet its the MAF sensor". So I bring it home, get a reman MAF sensor, start it up, runs like ass still. BUT,,,,, I hear a new noise and low an behold, the distributor is jumping around inside its housing like crazy. So I think I got the mystery solved. Here's the 1M question: How big of a pain is the replacement on these?
Distributor is easy. Just make sure you use a wax pencil or touch-up paint to mark the direction of the rotor before you remove it so you'll time it correctly. It has a gear on the bottom, so the rotor will turn as you remove/install the distributor. Just remove the cap, remove the 12mm hold down bolt after making your marks, pull up on the distributor to remove and reverse to install. Start the engine and get to normal operating temperature. Adjust the timing with a timing light following the service manual procedure.
On the road again
I just wanted to pass along the news that the issue was the Distributor for sure. I think the reason I did not catch it sooner was that it was making noise for a very long time before giving out. So there you have it. I wish to thank everyone for their thoughts and ideas. Now on to the next posting!
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