spark plug change interval
 

My 87 is running well but the power output during boost has suddenly and noticeably diminished. It's making full boost pressure, but the boost doesn't translate to as much power as before and there is a hesitation as well.

I'm thinking I'm lacking sufficient fuel or sufficient spark, but not seeing anything wrong and initial testing of fuel pressure is good.

I haven't checked my plug condition yet, but they are only one year old with 5000 miles. Do the copper plugs WR7DC wear out quickly? I will remove them and regap if needed, but was wondering about your experience.

Thanks!

Compression testing.
Sox

Go back to Bosch WR7DC plugs... the platinum and iridium plugs may do well at the beginning, but it is difficult when they go south. With the copper plugs, you can see when they are worn out.

Thanks George. I'm currently using the WR7DC copper plugs. How long do they typically last in your experience?

Probably good for 15K, then regap, do another 15K, then replace with new...

I had a car that ran perfectly until I got on the boost, and the turbulence caused by the boost blew the spark away from the mixture. Tough to diagnose, threw everything at it. Finally, a new set of copper plugs fixed it.