1971 Monte Carlo

Removed the old Chevy 350 engine with Edelbrock intake and carb, headers etc.

Installed a brand new Crate GM LS1 5.7L 3rd Gen engine.

Photos are here

Engine Details

5.7L Pushrod V8, mild cam, thermoplastic intake

Custom Fuel rails with stock 25lb/hr injectors, and a Bosch 044 Fuel pump with a rail pressure set at 55psi <stock injectors are 25lb/hr at 3bar> Injectors are High Impedence and the ECU is configured with the Transient Suppresion diode internally

Ignition coils

are logic level and there are 8 that have 4 pins each, Power, coil ground, signal ground reference and +5 V trigger signal. Coils require ~5ms of dwell but will run with up to 8 and have internal current limiting.

Firing order: .... FILL THIS OUT

Did you order ECU with 0 IGBT (8 logiclevel signals) ?

h[2]=70 60 50 40 30 20 10 00

suggests that you wired properly, and fire in this order (that tableline looks good allows easy verification of order anytime later):

ignition wiring:

h[1]=00 2A 24 1E 18 12 0C 06

suggests that you want to fire ignch7

so the TDC of ignch7 is 15+65=80 crankdeg

Is this a good assumption ?

Primary trigger

24 tooth Crank sensor with equally spaced Falling edge and unequally spaced rising edge read by a hall sensor that is powered by and outputs 0-12Volt square wave

Both triggers were verified on the scope and are clean during cranking both with and without a 40amp commercial battery charger hooked to the electrical system.

Secondary trigger

1 pulse Cam Position Sensor that reads a grove on the camshaft, also Hall that is powered from 12V and outputs 0-12V square wave.

The Cam sync signal going HIGH or LOW does not overlap with the main trigger signal, however it stays HIGH for 360deg's of Crank rotation and then LOW for 360Deg's

The scope shows that both camsync transitions occur approximately 7-7.5 deg's between the falling edge (appr midway, as 1 tooth=15 crankdeg)

Rising edge of the Cam Sync appears to Occur AT TDC for cylinder 1, that's what we configured: so the next crankpulse (falling edge) will be tooth0.


I'm sure i'm missing something obvious => firing order ???

Configuration and tables

I'm using Megatune 1.1.23RC with 1.1.18 firmware. 1.1.26 firmware was tried with the same megatune but resulted in many Resets showing in megatune every few seconds.

Links to Config & Tables below

I should have updated this page ages ago the LS1 runs beautifully on VEMS now I'll post up new configs of the last tuning we did. Its coupled to a 700R4 Auto trans with Torque converter lockup in 3rd and 4th gear has been on the road now for well over 1 year without any problems.