LS-1Z28

iTrader: (6)

is this the best practice to fix a poor idle?

I know there's a bolt on the throttle body that adjusts the throttle's idle position.

Paint_It_Black

iTrader: (1)

If the iac is maxed out, you have to drill out the hole. The improper fix is adjusting the throttle blade.

03EBZ06

consider:
pull the valve covers and make sure the valves are moving. do a static compression check. Is the cam dot to dot?

do a spark check, throw a plug on the exhaust and check it.

pull a plug and see if they smell like fuel.

fuel pressure??

make sure the batter cables are tight on the battery.

jaber911

injectors size lb ?
is it stock injectors ?

1998Z28LOADED

The bigger hole helps more air come in at start up. It makes a difference, I don't know if its enough difference to take it from completely not starting to starting. Maybe worth a shot.

Yte_sleeper

iTrader: (2)

Does your SECURITY light flash when you tried to start the car? If it does that means that the chip on your key is not making good contact.

joecar

Is the ECT sensor plugged in...?

AJK381

iTrader: (2)

Or instead of just drilling the hole out try lightly givin it gas while your turnin it over to see if not getting enough air is the problem

1998Z28LOADED

Yea but only about 10% throttle because it will flood quick.

Mumbles

iTrader: (5)

I'm with these guys.

I see no mention of having the PCM recalibrated for upgraded mill in the O.P. and it sounds exactly like a "One and Done" type of situation.

Thats where your new motor will fire up exactly once and the PCM can't keep up with the number of parameter changes needed that the engine dies and won't start again.

I'd look into a Mail-Order-Tune for the time-being and eventually a Dyno-Tune to safely optimize the upgrades.

Keep this thread updated. I'd like to know what you find. Good luck, man.

Z284U2TRY

iTrader: (5)

sounds like crank or cam position sensor.

NC98Z

iTrader: (1)

If this was what happened couldn't he take the battery cable off long enough to make the CPU reboot and see if it did the same thing?

dtroike

iTrader: (4)

I assume you have HP tuners since you mentioned the codes. Have you tryed loging any info such as injectors while you are cranking it over. Maybe you could try and disable the vats if the injectors are not firing. I would also check the plugs and see if for whatever reason they are wet. Is there a possibility of a loose or broken pin on the vcm where the harness plugs in?
I dont know if you changed the crank or not, but are you sure you have the right reluctor wheel. Are you sure the cam is installed correctly?
Im sure you will figure it out sooner or later.
Good Luck
Duane Troike

Mumbles

iTrader: (5)

Thats a good question.

I don't have the answer to it, but it seems logical that with the battery disconnected (both Negative and Positive Terminals) the PCM should reset. It would then attempt to re-learn to make the car idle/run properly.

If this is the case, the engine should fire and run for a short time before dying again.

Obviously this isn't the fix to the problem, but at least you will have pinpointed it.

I'd say its worth giving a it a try.

joecar

CKP has been eliminated, see these posts above:

joecar

Those U codes make me think either the serial bus or the PCM have faults.

Do you know that the cam was installed correctly...?