91 jetta gli intermittent lossofpower

have a 91 jetta 2.0 16v with cis motronic. Every once in a while i'll be driving and loose like 1/2 power, It will randomly happen, feels like retarted ignition, or lack of fuel. If I turn my car off and restart it tipically will go away, no vaccum leaks new Ias valve, cleaned all the electrical connections, good grounds, new ect, and new fuel filter. Every once in a while my idle is like 2500 rpm, then that goes away when i hit a big bump. Don't know if that's related or not. The car starts fine though. Any advise? Injectors are new also. The problem seems to be getting worse.-unplugged the knock sensors, changed ect, and checked idle switch. also 02 scales ok with fluke meter.