idle issue, fluctuates at times Options

[joeav8tor]

Hello,
my 73 2.0 with stock fuel injection is running pretty good, but at times the idle fluctuates (not surging)...when the car warms up the car usually idles at 900 rpm...then at the next light or stop sign, it will idle at about 400 rpm...the idle is not consistant...further down the road it might idle at 900 rpm when I stop again...any ideas...I recently dropped the engine and installed new vacuum, fuel lines and did a complete tune up....the AAR is working properly...anyone else experience this problem?
thanks (IMG:http://www.914world.com/bbs2/html/emoticons/flag.gif)
Joe

[MarkG]

I am experencing same issue ('76 2.0, 20k on engine, entire FI system new or rebuilt except for ECU and harness....). Up untill 2 weeks ago car could sit for a month, I would turn the key and it would start and idle perfect.

Now it wont start at all on first try (idles for a few seconds and dies; second startup and it will idle real low). It idles @ 200-300 RPM until hot (not warm - hot) then will idle @ 900 but you can hear a surging to lower RPMs and back up to 900, not not surging from 900 RPMs to higher RPM range. AAR is fine....

I lost #4 cyl, traced it to defective injector, replaced all 4 and car runs great @ speed but still have surge/low idle issue. I have spare rebuilt MPS I will try, see what happens, bound to be something simple ......