Been tuning on my 86 GN and so far the chip seems to be the best improvement in overall driveability. Took care of severe stumble when accelerating, idle quality improved, and what seemed like a mis fire has gone away. Now the bad- b/4 installing, I was consistantly getting a 90 BLM-which tells me the ECM was having to lean out the engine for some reason. Now the chip sets BLM at 118 and when I let car sit and idle, the ground turns black from rich soot out of the exhaust. Plugs are very sooty, but electrode resistor is still clean. Plugs were always very consistent and clean b/4 chip change. Mileage is sub 10 MPG, but car seems to run well. Here is what has been done during my "spring" tune up:
new fuel filter
hot wire kit
new Walbro fuel pump/sending unit
pcv valve
oil with ZDDP additive
Autometer boost gauge
metco fuel gauge -hood mounted
new radiator and system flush
Have not changed any wires,plugs or electrical parts
Other pertinent data
fp 37-42, and at least 1-1 under heavy acceleration-up to 60 psi
vacuum 20 at idle
boost maxes at 15
still can't break tires loose from dead stop, but back end will fishtail right b/4 2nd gear when heavy accelerating
scanmaster numbers
o2 850
af 04
lb 30
clt 171
tps .44-.46
iac 24-29
bat 13.7-14.3
int 128
blm 118
rpm 750-875
mal 00
new fuel filter
hot wire kit
new Walbro fuel pump/sending unit
pcv valve
oil with ZDDP additive
Autometer boost gauge
metco fuel gauge -hood mounted
new radiator and system flush
Have not changed any wires,plugs or electrical parts
Other pertinent data
fp 37-42, and at least 1-1 under heavy acceleration-up to 60 psi
vacuum 20 at idle
boost maxes at 15
still can't break tires loose from dead stop, but back end will fishtail right b/4 2nd gear when heavy accelerating
scanmaster numbers
o2 850
af 04
lb 30
clt 171
tps .44-.46
iac 24-29
bat 13.7-14.3
int 128
blm 118
rpm 750-875
mal 00