While cruising on the freeway in 6th gear today something strange happened. The engine started to ping and I saw some smoke in the rearview mirror. While this was going on, the car was bucking a little. I backed off the gas right away and expected the worst, but the problem went away as quick as it appeared. I was into the throttle just a little bit - barely boosting. The problem didn't show up again all day. When I got back home I scanned the ECM, but there were no codes. Has anyone had this happen to their Evo? Did a search on this issue, but found nothing. My car only has 4000 miles on it with just a CBE. I don't drive it too hard and changed the oil 3 times already.

I'm worried about toasting the engine if this happens again under boost. I'm thinking the MAF sensor is starting to go bad

Any suggestions?

 

Were you going about 80 mph when this happened?... I'm not exactly sure and I may be wrong but try doing a search on compressor surge and or BOV. This used to happen to me too when I only had a CBE, when I would boost slightly and part throttle in 5th around 80mph. The only way around it is to floor the pedal more.

But my car doesn't do it anymore after adding a TBE.

 

I was doing about 70 mph - was just feathering the throttle into boost.

I'm assuming the smoke was due to the knock being compensated for by the ECM?

I don't know whether I should take the car to the dealer or try to figure it out myself using a data logger.

 

have you been using any fuel additives?

 

I use only premium from 76 or chevron - no additives whatsoever

 

This knock that you're speaking of. Are you refering to the car slighty bucking or surging back and forth? Or are you actually hearing the engine knock or ping when this is happening?

The smoke is there because the car runs really rich.

I think you should do a search under compressor surge.

 

In reference to the bucking it felt like the car was loosing power and I was hearing moderate spark knock. It was like the engine was misfiring on the same cylinder repeatedly - as if one of the fuel injectors was dropping out.

I did the search on compressor surge, but didn't come up with anything applicable to my scenario.

Does the 4g63 in the evo have an egr valve?