What do I need to buy to tune my worked VN 5L?

[antus]

for the iac you want to let it warm up and watch the iac steps in the logs and close off the butter fly until the ecu is reporting about 30 steps. Then it should have enough range for all temps. If you close the butter fly off fully and its still idling too high then you need to check for air leaks or if its not a factory throttle body see what you can do to reduce the amount of air getting in, and if all that fails, then you can try and pull a bit of timing in the idle spark table which might help a bit but the correct answer is less air.

[engybenjy]

Thanks antus I will try that next available tune

[jon]

I hope this doesnt sound like a stupid question but is there a different VE Table for just the idle? I had it on the main VE table with the bubble mode on and adjusted the value with the bubble over it and would have to make a drastic change to get any real change in A/F at idle. Then if i gave it a quick rev the A/F ratio would not settle down straight away back to where I set it even though the bubble was over the same box. eg, A/F seems to be around 12.3 if not in closed loop mode, adjusted the box to get about 14 but after a quick rev it would hover around 15.3 then come back down to 14. is this normal?

[VL400]

The only way I can get closed loop is to bring the revs up then bring back to idle but then it will go into open loop mode a short time later.

There is a item called "Idle Fuel Param - Delay before using idle A/F ratio". You will be using the normal target AFR table (which is likely 14.7:1 and hence closed loop) until the delay timer expires at which point the target AFR changes to the idle AFR table. The VE table is still used for the VE calc, its just the target AFR that will change

[jon]

That makes a lot more sense now. I have found that because I am starting to tune from a factory bin the ve table is out a fair bit. I found a bin in the custom tunes referring to a 284 crane cam and standard injectors but its not $12p. If I copy the ve table and spark table into my tables would that be easier than starting from a standard tune? The cam and injectors match what I have.
Jon

[Holden202T]

its really depends how much other stuff has been changed. for example, if the AFR table has been changed it can effect the results, assuming everything else is not too fiddled with the two tables you mention will possibly get you closer to the mark than a stock tune.

[jon]

I just went through some of the high and low temperature cut offs and noticed a few things that seem to be out of my engines temperature range. I have a 160 deg F thermostat instead of the standard one which I believe has my engine running at about 71deg C. From what I am reading I have to lower the low temperature cutoffs on the ones in the pic provided to 56deg C ?
Also running an A/F ratio of 13.9 at idle because the engine does not get quite hot enough for 14.1 is ok?
In saying all that would it just be easier to put the standard thermostat back in?
Jon

[Holden202T]

i'd be interested you know why you are running such a cool thermostat rather than a 85 degree type one ?

all the things you mention can be changed to work at a lower temp but in my personal opinion things like engine wear, fuel economy and heaters (in winter) all seems to be better with a 85 - 90 deg thermostat ?

[jon]

Thats the sort of answer I needed to change it back to original. Before I found this site and modified my computer I ran into problems once the new exhaust was put on. I found on hot days the engine would lean off a bit and start to get hot. The only way it would cool down was to switch it off or let it idle for a short time. Someone mentioned that if I ran a colder thermostat it would fool the computer and run it a little richer. Found out pretty quick that it didnt help the situation so I just parked it up until I could justify spending $1250 for someone to tune it. The only reason it wasnt tuned yet was because I wanted to do more work to the engine and I wasnt going to spend the $1250 every time I changed something. I was going to change the thermostat back a while ago but the guy who built the bottom end of my engine said it would probably produce more power running a little cooler.
Jon

[Holden202T]

yeah well i guess it depends on the personal opinion of people and different motors, personally i found when i put the ecotec in my torana and used a 81degree thermostat that it was actually getting too cold (74 degrees were seen in logs in winter) so it was making things like lean cruise and such turn on and off and i was feeling jolts when cruising when that was happening, i also found the heater wasn't working that good.

so i then put a 87 i think degree thermostat in it and it solved all the problems and i actually gained some economy.

i guess my short answer is if your engine is getting hot and wont cool down there is another issue, ie. radiator not big enough, blocked, not enough air flow etc. unless its running REALLY lean i wouldn't think the tune would be causing it to overheat..... that said it may not be helping a borderline system.

i guess at the end of the day the choice is yours weather you change those settings or change the thermostat etc.