Need helps gents, first LS1 car and its a doozy to get broken in on

[angrygoat]

I am trying to help my friend with his 414 LS1. Its a 6.0L block with LS7 heads and a GMPP intake. I would have to get the cam specs from him. We are going to run a SD tune. We tried for a couple of hours to get it to start and idle and all it wanted to do was pop out of the intake and exhaust. I tried idle timing from 14* all the way up to 32*. The engine was ran on the dyno with a carb before being shipped out and they told us they ran 28* at idle. I tried adding to the cranking VE, RAF and idle spark tables. I also tried playing with the abs timing in the vcm controls. Did I just skip something in the tune?? Thanks for any help.

-Joe

edit: cam specs are 249/261 110 LSA hydarulic

[blownbluez06]

Any custom wiring on the car? Coils re-located? Checked all your grounds? Sounds like this may not be a tune problem.

[angrygoat]

There was nitrous on the car but it was removed when this engine went in. The coils are in the OEM spots on the valve cover. We did have someone checking grounds but maybe we need a second set of eyes on it.

Does the tune seem ok to at least get it started??

[C5 2000]

With this tune you are not going to start the car.Use Russ idle cfg to find out your Base Running Airflow, Startup need work too, try to work on the IAC count, and Main Spark need lots of work (put stock spark back and start from there)..Big cam like that need at least 40* in the Idle Spark vs Airmass, also Idle Underspeed Spark.. I would tune it SD open loop and LTFT Boundaries map should be at least in the 70 or 72 range..Good luck

[99LS1SS]

C5 2000, I'm confused by your 40* timing comment. I'm new to HP Tuners and I've got a LOT to learn. I think I've read that big cams liked lower timing at idle. If I haven't misunderstood 5_liter_eater, that is what he said. I'm not saying one is right or wrong, I just want to know what to do.

[gsegse]

cams need inc. idle timing but not 40* very high ...just my Opnion

[69lt1bird]

What injectors are you running?

[angrygoat]

The injectors are 42# green tops. This isn't the last tune I tried, this is the one I simply took his previous tune and updated the IFR and cyl vol. I deleted the others and was going to start over with this one since it wasn't improving. I made numerous timing, idle airflow, and cranking VE changes with no improvement. I tried stock idle timing all the way up to 32* which we were told to run by the engine builder

[69lt1bird]

Your short pulse adder table does not look right, I would double check the data.

Add about 15% to the primary and secondary VE tables.

Get the idle spark up in the 27-28* range, not 40.

[angrygoat]

I should have mentioned that we are running an SD tune. If I understand the LS1 ECM correctly the primary is not used with the MAF failed, only the secondary correct?

[69lt1bird]

I believe that pertains to open loop tuning, once back in closed loop, the primary is still active. Just paste special into the secondary and copy the even rows to the primary and interpolate the odd cells.

[angrygoat]

ok, I made the primary and secondary match. I played with the idle timing from stock to 40+degrees. I also kept playing with cranking VE an the secondary VE to try and find the happy spot. I still can't get the engine to idle without popping out of the exhaust