Misfire at 3000

[UnexplodedCow]

Not all under 3k rpm problems are ignition. I have a '90 LX that wouldn't rev past 3k. I replaced the coil, and it still had the problem....turned out the fuel pump was bad.

[Lynde]

Originally Posted by chevyn0va1

You seem to have all the answers already but I stilll suggest checking the plug wires, plugs and maybe the coil (pack). If you are chasing the slugging from the a/c that my car (and others on this forum) have good luck if you find it please share with the rest.

You can also develop a misfire with a faulty fuel injector. Try performing a noid light test first, to make sure you have a good pulse to the injectors.
another thing to try is changing to A/C relay and the WOT relay (wide open throttle) Ford had a lot of problems with those relays. They are located on the fire-wall passenger side top of the engine compartment.

[Lynde]

Originally Posted by JMorales

My girfriends 93 1.9 has a slight misfire at about 3000 rpm, but only when the ac is on, otherwise it has plenty of power. It has new wires, new fuel filter, new air filter and platnium plugs but the misfire was there before I changed all this. It is only slight but anoying and usually only in 2nd gear.

JM

If your car has a misfire, then it should set a code in the computer.
Also a faulty fuel injector can cause a misfire. But it would happen all the time not just with the A/C on.
Ford Escorts had a terrible time with the A/C relay and the WOT (wide open throttle) relays, not working properly. Try changing them. They are located on the fire-wall,passenger side, engine compartment. One is Gray and one is brown. Replace them in pairs.