I have an 89 FB 5.0 TPI. I started noticing a hesitation and jerking when at slight throttle to maintain speed a while back. Accelerating was fine, idle so-so. Now it's idling terribly at times, the jerk in the car is more and also does it at 50 mph. I got after it the other night and it started breaking down and losing power around 3000 RPM. I'm thinking fuel pump or maybe CATs. I've contemplating changing plugs and wires but they're not that old and I'm not sure they're the issue. Looking for diagnostic help. Thanks

 

Sounds like the infamous Multec fuel injectors are failing. ohm them out and I'll bet you find a few shorted.

 

Thanks for the tip. I ohmed the injectors and got readings from 4.7 to 15.7. What range should they fall in? Looks like you're right about the injectors.

 

Around 15 ohms. That 4.7 is your problem..

 

A new set of injectors it is. I changed plugs and fuel filter today because they're cheap and I was hopeful. But no improvement. Thanks for the help.