Hi All.

I have an odd thing happening to our 1994 Honda Accord VTEC with 191,000 miles. Between 2000 and 2500 RPMs on acceleration I get a pretty bad vibration. It mostly happens when it is in 4th gear but I have felt it at other speeds as well. I thought I remembered reading here someplace that it may be the torque converter starting to go out on the transmission. The other day I decided to check the spark plugs thinking it may be a missfire, but why would it just be at that RPM? I pulled all plugs, one had some oil on it from a leaking o-ring gasket but looked ok, but on the next 2 cylinders the spark plugs were all covered with a light powdery substance which I was told was a symptom of just running hot. I replaced the plugs and nothing changed. Before I take it in to the dealer and pay $120 just to have it looked at I wanted to ask the question here. Any ideas?

Thanks!!

 

How much oil on the one plug? Enough to short some of the spark to ground? Fuel mixture is more difficult to ignite at some loads & rpms, so a marginalweak spark can misfire under some conditions & fire OK otherwise.

Open the hood after dark, turn out all the lights, start the engine. Look for arcing around the cap & plug wires.

 

Hi.

I was thinking the same thing about the oil shorting the plug but I do not think it was enough to get up into the top of the plug. Wouldn't it affect the engine at all RPMs then if it was shorting? I did also try to look for arcing spark with the lights out, nothing.

Thanks.

 

If it was only shorting out a little bit(?), it could misfire in some conditions, but fire OK in conditions where the mixture was easy to ignite.

WhatI wanted was for you to check it, & it sounds like you did that & ruled it out.

 

Hi All.

Just an update. I did find out what the problem was, it was the exhaust gas recirculation system which is located under the fuel rail. 3 of the 5 ports were blocked solid. Cleaned those out and put it back together and the problem was gone.

 

Thanks for letting us know.