LS1 pcm to run 5.3, firing order is different?
11-10-2012, 04:31 PM
#1
LS1 pcm to run 5.3, firing order is different? I have a 1999 5.3 set up to run on an engine stand. It's controlled by a 2002 LS1 computer with every stock 5.3 table copied over to it with HP Tuners.
It runs ok but doesn't idle well at all. Also idles very, very rich.
I pulled this engine out of the truck and it ran perfect but sat for a year and a half.
So right now I was double checking the two programs and noticed that the firing orders are somewhat different.
It's all on my laptop so I'll show it like this
The 5.3 table looks like this:
.....7th..8th..1st..2nd.3rd.4th.5th 6th
cyl 5.....4....3......1....8....7....2...6
LS1 table:
.....7th 8th.1st.2nd.3rd..4th.5th..6th
cyl 4....3....1....8....7....2....6....5
What will these being off effect?
It doesn't make sense to me why they are like this.
It runs ok but doesn't idle well at all. Also idles very, very rich.
I pulled this engine out of the truck and it ran perfect but sat for a year and a half.
So right now I was double checking the two programs and noticed that the firing orders are somewhat different.
It's all on my laptop so I'll show it like this
The 5.3 table looks like this:
.....7th..8th..1st..2nd.3rd.4th.5th 6th
cyl 5.....4....3......1....8....7....2...6
LS1 table:
.....7th 8th.1st.2nd.3rd..4th.5th..6th
cyl 4....3....1....8....7....2....6....5
What will these being off effect?
It doesn't make sense to me why they are like this.
Last edited by Jays_SSZ28; 11-10-2012 at 04:37 PM.
