Erratic idle - EA MPFI
I have a rather annoying problem. My base idle is fine, if I'm in gear or the isc is disconnected, the car idles perfectly at around 650-700 rpm.
When I am in park, however, it's a different story. I started the car earlier, got it warmed up, and when I pulled over and put it in park I noticed the idle seemed to be hunting.
It'll sit at 800 rpm, then go up to 1000, then back down, then up, and so on and so for at around 5 second intervals. This only happened *after* I turned my headlights on.
Is this likely to be a dodgy alternator, low battery voltage, or is my isc stuffed?
Any help would be appreciated, it's driving me nuts.
EA GL-Ghia pseudo operator
3.9 MPFI converted 4 speed
2.5 inch exhaust
NC Ghia interior (except rear trims)
Fairmont audio (with 4 speakers)
S-pac cluster with white dials
Trip computer and Fairmont interior lighting.
Half wired Ghia BCM.