92 Loyale,

105K miles on 1.8L EA82

195K miles on the rest of the car

 

 

Today I am getting backfiring - when accelerating, I hear this loud "poof" type of sound coming from exhaust and the whole car shakes and hardly accelerates. This backfiring and hesitation happens mostly at 35-45mph but can happen at any speed.

 

And, it misses at idle, and I can smell gas from inside.

 

Is the catalystic converter plugged up with such high mileage?

Or some kind of ignition problem (Like coil?) The plug wires are about 6 months old, but the local parts store had the cheapest kind, you know, the $12.99 type.

my guess is the timing is off or plug wires are switched

I have not messed with plug wires in a while, they worked before (but I will upgrade).

 

Thus far I have narrowed down the choices to :

 

• The knock sensor retarding timing (happened on a Chebby once)
   
  
• The EGR valve getting plugged up with such high mileage.
   
  
• sticky vacuum advance mechanism.
   
  
• timing off.
   
  

 

What's the most likely cause of this?

check your distibutor cap very carefully for hairline cracks or carbon tracing on the inside

sounds like you have a plug wire shorting out.. or the coil wire..

 

wait till its dark outside, then start it and look under the hood.. find the throttle, rev it a few times while looking around the coil wire and plug wires.. if its jumpin spark, you'll see it..

 

90% of the time when a cat gets plugged it will smell like rotten eggs..

I will follow this advice.

 

But, the backfiring stopped. It only lasted 1 day. I used 89 octane gas, and I think it made it better, and improved my mpg from 29 to 30. Although it doesn't do anything strange with 87 either.

 

Hm.. maybe water in gas?

maybe a bad tank of gas.. been there done that.. i only run sheets in my cars now.. much better than exxon, lol..