Hi not sure if any one can help but having a bit of an issue with my 1990 NA automatic. Whilst in drive and either moving in very slow traffic or when slowing down to stop at a red light for example the engine begins to start hunting between around 700 and a 1000rpm. Once at standstill the idle is fine. Have changed all vacuum pipes and cleaned idle control valve. Any ideas to try would be very appreciated.

Hi,

yeah, there is a lot of preventative maintenance you should do...

 

First check your work to make sure there are no air leaks. (particularly if there wasn't a problem before you did anything).

 

then check and clean all connectors (some are hard to get to).. so MAF, TPS, PTU, IAVC, CAS, injectors, ecu temp sender unit ... etc...

 

after that there are settings that need to be checked ...

 

this is good:

 

http://www.twinturbo.net/nissan/300zx/forums/technical/view/922678/The-6-Ps-Proper-Preparation-Prevents-Piss-Poor-Performancegt.html

 

this is another good one:

 

http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.335

 

 

good luck..

Time for the 6 monthly connector clean session methinks buddy.