2000 Lincoln Ls Problems with misfiring

[natesr70]

I replaced the coils and the spark plugs and valve covers but it's still misfiring. What should I do? I put autolite spark plugs in it instead of motorcraft will that make a difference. It idles fine until I give it gas then it hesitates and wont hit the high RPMs

[shorod]

Have you taken it for a drive, or have you just tried revving it in the garage? The reason I ask is because therw is a rev limiter at about 3000 rpms in park and neutral. When the limiter kicks in, it feels like a misfire because that's basically what it is. The PCM shuts off fuel to the injectors to limit engine speed.

If the misfire is there while driving as well, then have you checked for vacuum leaks and made sure the intake air tubing is secure? Which engine do you have?

-Rod

[natesr70]

I have a V6 engine and I checked all the vacuum hoses. But I'll take it for a drive and see if it will still misfire.