i have a problem on my jap 92 N/a idle. Starts on the button every day and tick over is usually about 800rpm but every so often (getting worse) goes upto about 1800rpm and sits there, engine can be cold or hot and will sit at a constant 1800 rpm from anywhere between 2 mins and 30 mins and then will return to a constant 800rpm. Anyone give me a few pointers on where to start?

cheers

i have a problem on my jap 92 N/a idle. Starts on the button every day and tick over is usually about 800rpm but every so often (getting worse) goes upto about 1800rpm and sits there, engine can be cold or hot and will sit at a constant 1800 rpm from anywhere between 2 mins and 30 mins and then will return to a constant 800rpm. Anyone give me a few pointers on where to start?

cheers

 

 

check TPS settings should read 0.40-0.50v at idle can be set using a multi meter connecting the red probe to the centre wire coming from the tps connector passenger side of the plenum then ajust the 2 x7mm screws carefully until voltage of the above figure is achieved

reset ECU

clean temp sender

do a consult check!

check iaa unit clean warm up idle connection clean unit if required theres an article on tt.net.

set base idle using ajustment screw on side of IAA unit

 

dont mess with the IAA unless all the other jobs fail to cure!

 

boost leaks?

dirty connections?

 

theres a few problems that cause symtoms like hesitation/erratic idle start with the simplist then work through

 

start with removing the battery for an hour then reconect,you will surprised what a simple thing like that can do by resetting the ECU

Mine was doing exactly the same recently cleaned TB's IAA unit and re-set ECU for an hour hasn't done it since ;o)

cheers ill give it a try