Hi all,

I recently finished my build with a new engine, installed the motor back into the car and everything runs good but I seem to be fighting a hanging idle issue. I did a base idle reset and set my idle to about 800rpm because I have a E303 cam. When I start the car up it idles up at about 1000 rpm until i push the clutch in, then it will idle down to 800rpm. I didnt notice this issue when I had my stock motor in but all with the new motor its doing it. I have done a vacuum leak test and found I had a leak coming out of my EGR diaphragm, but this didnt fix my issue. after reading many threads I looked into my Neutral sensing switch, unplugged the connector from the clutch switch and jumpered it out to see if that was the problem, of course because that is in parallel with the clutch switch it dropped the idle down. So then I got thinking why isnt it working when I have it in neutral. I climbed under the car and metered out the harness going to the NGS and the switch was closed when I had it in neutral or in first so maybe it failed closed? But if it is closed why is my idle hanging?

For background on the car it was originally a 85 CFI Auto that got swapped over to EFI T5 manual from a donor car by the previous owner. I did a MAF upgrade a couple years back when the original motor was in the car and it ran fine with no hanging idle issue. Is the wiring harness different from 86 Auto to Manual? I have the Speed sensor plug, reverse light plug and NGS all connected. I did check my O2 harness and sensors and they are 86 sensors with harness, no jumper.

Sorry a little long winded but just trying to dial this thing in. It runs good but the high idle is annoying

Thanks