85 Misfire issue

[YungICY]

I have an 85 ranger with the 2.3 FI Lima that has developed a worsening misfire or possible detonation. I'm not really sure what to check first.

I have replaced the low pressure fuel pump about 8 months ago. I replaced the spark plugs and wires about 4 months ago. Shortly after I replaced the plugs and wires was when the misfire started happening due to cheap quality wires. I replaced that set with a better quality set and it seemed to help but lately it has gotten bad and is only getting worse.

Is is possible that I just have a fouled up plug from when I had the first set of wires?

Also it could possibly be detonation. I have a K&N filter that isn't in a box and I have cut off my muffler. I do have a narrow band AFR gauge that other than being great for a light show in my cab, it does show a rich mixture when I get on the throttle. Which I would think means I'm getting plenty of fuel and not detonation.

Also note that it misfires when under heavy load/acceleration.

 

[86MUDRCJ]

I would check the plugs to be sure. Also I don't think having a filter outside of an air box would do much as far as making it cut out.

 

[YungICY]

Alright, I'll go check the plugs and see what I find.

 

[YungICY]

Pulled the plugs and found that one of them was really fouled up and it was also gapped about .008 too big. Cleaned them off and regapped and took it for a drive everything is running good now.

For future reference, what are the best plugs for replacement? I like to replace parts with performance parts when they go out so I'd be looking for a performance grade plug.

 

[Jraymer360]

Pulled the plugs and found that one of them was really fouled up and it was also gapped about .008 too big. Cleaned them off and regapped and took it for a drive everything is running good now.

For future reference, what are the best plugs for replacement? I like to replace parts with performance parts when they go out so I'd be looking for a performance grade plug.

motorcraft or autolites.

 

[adsm08]

For future reference, what are the best plugs for replacement? I like to replace parts with performance parts when they go out so I'd be looking for a performance grade plug.

Yeah, that isn't always a great idea. I understand wanting to squeeze every little bit out of your engine, but most of the time it's a trade off, and sometimes things just work best stock.

The TFI ignition system seems to be happiest with copper Motorcraft or Autolite plugs.

Platinums seem to burn up faster and other brands seem to cause misfires.

 

[YungICY]

Yeah, that isn't always a great idea. I understand wanting to squeeze every little bit out of your engine, but most of the time it's a trade off, and sometimes things just work best stock.

The TFI ignition system seems to be happiest with copper Motorcraft or Autolite plugs.

Platinums seem to burn up faster and other brands seem to cause misfires.

That makes sense. Thanks guys.