caution58

How can you tell if this goes bad. Also if it does will it affect the way the truck runs. And does it just go bad or continually get worse. Wondering if this is what wrong with my 92 f150 4.9

Welder7018

It's possible and of it does it will affect the way it runs since it won't be building a hot enough spark to ignite the fuel/air mix efficiently.

papa tiger

Have you changed your fuel filter? Test your fuel pressure also if you have.

caution58

Yeah I've replaced the filter and the pump and now getting plently of pressure at the rail. Also replaced the fuel pressure regulator. I thought is was somewhere in the fuel delivery as well but did all that with no change.

papa tiger

Def look at ignition parts. Take a compression test to see if all cyls are equally high psi.

dr_bowtie

Coils wear out and should be changed every 60,000 miles to keep optimum... new model coils last much longer as they use coil on plug and they dont work as hard as one coil per engine