After some frustrating moments it seems that resistors are a no no.
But I read somewhere that the EEC-IV can actually stand low resistance injectors quite nicely so I'm not majorly worried. Altho I bought myself a set of 332cc/min 16 ohm injectors so maybe at some point I will be installing them.
Changed the spark plugs to colder Motorcraft ones.
After all the problems I've had with this today finally I got it running right.
Funny incident happened, while I was on my maybe second or third test run suddenly it stopped making boost and started to jerk annoyingly, but good thing is that I was still able to drive back home. At home when engine was running I popped the hood and didn't seem to find any disconnected boost pipes or anything so it got me wondering whattehell was this. Then I applied some throttle and it became very clear, the little "patent" (piece of iron wire) what was holding wastegate actuator's linkage to the wastegate itself had failed and the wastegate arm was jumping around like mad.
After mending this little problem I was good to go and had finally found a quite good setting for the VAF spring so now I had really good AFR readings and car was very drivable no any jerking or anything weird as easy to drive as my N/A stock injection Pinto.
Maybe some people with their 500 bhp Cossies don't feel this as anything special, but I gotta say it really felt awesome to first time in my life to have a nicely pulling turbo engine under the command of my right leg.
Also gotta love the turbo chatter even if it wasn't really that loud with the current boost (about 0.75 bar was the peak). Tomorrow I'm probably going to make the VAF's spring a tidy bit tighter and hopefully it's going to make the AFR a little bit leaner on lower RPM without affecting on boost ratios.
Also noticed that really the back muffler needs to be removed. Just too civilized sounding for my taste currently, I like my engines in a bit of a hooligan side.
-EDIT- Forgot to add, yesterday I bought myself a full rear axle with LSD and disc brakes. Going to make it under this car at some point.