my 89 is running like crap. i just replaced all injectors hoping it would help but didnt. im having this problem when i rev-up the car or drivin it kind of stumbles and sounds like its missing. i checked my vac lines and have replaced some and they all seem good. any ideas? i was thinking it might be some bad battery cables?

 

Have you read the plugs to see if they indicate any problems? Are the plug wires damaged at all? Do you see any arcing around the wires when the car is runing in the dark? How many inches of vacuum are you pulling at idle? How about fuel pressure at idle? How's the MAF sensor looking? May be worth cleaning it.

 

all thats stuff looks good i havent checked vacum or fuel pressure. and its not a mass air motor the car is 89 motor is SD

 

You converted it to Speed Density?

 

i think it was orig 4 cyl and someone threw that motor in

 

First thing is to check fuel pressure, if low filter or pump
Second go straight to the Distrubutor, that was my stumbling problem.

 

What kind of spark plug wires are on the car?
How old? Condition?
What type of spark plugs?

 

filter and pump are fairly new i have replaced both. the plugs and wires were replaced not to long ago and they are autolite and wires are accell. where should i check the distributor besides cap and rotor.

 

If it was an 89 motor and they did a 4cyl swap, and used the 89 computer, you need to get a MAF!

 

Check your salt & pepper shakers near the firewall. This was my problem. I'll try and find the link on how to do this.

Here:
http://fordfuelinjection.com/?p=85