New start-up help

[Steve Wood]

I keep forgetting...p robably is the ground altho the SM voltage comes out of the ECM and the feed to the ecm is normally thru the ecm fuse.  There is an ecm ground wire in the bundle that normally goes to the back of the head but grounding the ecm case should also do it as I recall.

First trick is to make sure you have good voltage at the ecm fuse and then onward from there to the ecm input.

[Scoobum]

Will do. Everything has its own ground. (plastic car) Doesn't mean I didn't miss one. 
 I think the alt. is showing its age. Should have around 14.5v at idle..13.8 its not charging the battery enough between start-ups.

When you get a BLM reading with the engine warmed up post it. Idle fuel for the Z06 can be adjusted for lean/rich via numbers 7 and 8.

[V6DVette]

Will do. Everything has its own ground. (plastic car) Doesn't mean I didn't miss one. 
 I think the alt. is showing its age. Should have around 14.5v at idle..13.8 its not charging the battery enough between start-ups.

When you get a BLM reading with the engine warmed up post it. Idle fuel for the Z06 can be adjusted for lean/rich via numbers 7 and 8.

Ok heres the latest#s cold & hot
o2-800      761
af-05          05
l8-38          34
bat-14.3    14.0
int-128      128
bl-128       118
mph
clt-120      164
ats-67       108
r-850         950
tps-44         44
iac-175        00
New NGK UR5s set @.30
A little hard to start today. Would start and stall till I opened the throttle some to get her to stay running. Then ran rough for a few secs.Then idled ok as I slowly let off the throttle.
ECM ground is off the frame and shows almost no difference from its bonding point to the frame.
 I did notice as the engine warmed up the voltage from the Alt. went down some. Like .5-1.5 volt which by the time it gets to the battery is about 13.5 and less when the fan starts.

[Steve Wood]

The car is showing slightly rich when warmed up...but, I would not be concerned until I could drive it about five miles to see what the chip can learn.

the IAC either is not adjusted correctly, or, it may not be working right.  Normally, down here, mine will run around 60 or so when cranked up and warm up to around 10-30 when adjusted right in Park...it's not critical as one may hear.  If it is reading 00 it is holding the blade off position and is not controlling idle.  As I said before, about 1.5 threads emerging is approximately correct

I never believe the PL voltage reported to be gospel.  It's an A to D conversion and it often changes, in my experience, as the ECM warms up.  I would check the voltage coming out of the alternator and see what it says and then read the voltage at the fan connector to see what it says.  I also usually check the voltage in the ecm voltage fuse connectors to see what is going to the ECM.

If I recall correctly, the path is alternator to battery to starter to fusible links to bulkhead connector to the ignition switch to the ecm fuse to the ecm.

I have found, several times, that the ignition switch connectors are not making good contact and the voltae will jump around when you touch them.  Also, I have seen a few that had corroded contacts in the fuse holder (ecm fuse)  Not so uncommon in cars that have sat a lot, I think.

I have also seen the SM voltage change with different ecms...best to check actual voltages in my experience rather than scan tool voltages...tha t's my experience