I have a 1986 Fleetwood Brougham with 135,000 miles - 5.0 litre engine. Check engine light goes on. Took it in for service but it still seems to run on 7 cylinders - idles really rough. There's spark in every cylinder and good compression. My mechanic gave up...any ideas? Thanks!

What was the check engine light code? Random misfires?


If spark is good and you have compression, I would assume it is fuel related.

Dirty/ unplugged injector? Whats the code that pops up?