Well here we go again ill cut to the chase...its a sohc zc vtec...obd1--new plugs properly gapped..(1.1mm maybe a bit larger) car was timed..dizzy looks good. I checked the injector wires and the injectors and they look fine. plug wires are beldens and fairly new. Im running a p28 thats new, o2 sensor is new, put a high flow cat on there--car was running pig rich due to no iat sensor and no o2...well thats fixed so im assuming its running less rich--o2 voltage is reading around .73 mv....did a little seafoam cleaning as well...every now and then the car sounds like its only running on 3 cyls..then itll run ok but then miss real big at like 3k...then itll stop and run fine...then run bad. Then like it will run fine for the next 4-5 days...then randomly run horribly one day. Im out of ideas guys!

 

Miss real big at 3000, are there any codes in your ECU's memory? That seems like an ignition fart which could mean a whole slew of things. I used to have interference on the distributor wiring and life would be miserable between 3000 and 4000, thenit would throw a code just to annoy me even more.

 

ah well--sorry i forgot to mention..im throwing an o2 heater code (41)...now back to what you said..sometimes! it will miss at 3k...but lets talk about this in percentages...out of ALLL the time i drive my car i would say that i take my car up to 6.5k with out any misfireing about 90% of the time..that little 10% is when itll miss..could what you have suggested still apply?

 

Yup, with wiring, all things are possible. My interference would only occur when the 12 volt starter line crossed the jumper harness coming in from the bottom of the firewall.

 

so should i just check all my wiring for bad joints/ any possible grounding out points? --i did this a bit..right at the ecu and resoldered some things but alot of it was in electrical tape

 

bump! checked them!