Can you "tune" the Cranking VE Table?
#1
Can you "tune" the Cranking VE Table?
Has anyone ever had any success of tuning the cranking VE table?
I noticed on start ups, that my wideband o2 reads 'too rich' on start up and then it leans out to 'normal' after about 10 seconds or so. This is after my Main VE table is tuned.
Exactly how does the Cranking VE table work?
Bill
I noticed on start ups, that my wideband o2 reads 'too rich' on start up and then it leans out to 'normal' after about 10 seconds or so. This is after my Main VE table is tuned.
Exactly how does the Cranking VE table work?
Bill
#2
TECH Senior Member
iTrader: (4)
I dont know that you can really go by an oxygen sensor during cranking. If youre not having any problems starting, I wouldnt mess with it too much.
But then again, I did lean it out just a tad after the cam went in. I just figured since youve got to trim the low end of the VE, probably wouldnt hurt to do the same to the cranking VE.
But then again, I did lean it out just a tad after the cam went in. I just figured since youve got to trim the low end of the VE, probably wouldnt hurt to do the same to the cranking VE.
#3
TECH Fanatic
iTrader: (1)
this is a feature, not a bug
when engine is cold, so is the gas. since you don't really burn gas itself, but its fumes, the gas has to be up to certain temperature to evaporate quickly enough. so the cranking AFR (look at OLFA as well) is really really rich, for the very pupose of generating enough fumes to start it up, when the engine is cold.
when engine is cold, so is the gas. since you don't really burn gas itself, but its fumes, the gas has to be up to certain temperature to evaporate quickly enough. so the cranking AFR (look at OLFA as well) is really really rich, for the very pupose of generating enough fumes to start it up, when the engine is cold.
#4
Originally Posted by RedHardSupra
this is a feature, not a bug
when engine is cold, so is the gas. since you don't really burn gas itself, but its fumes, the gas has to be up to certain temperature to evaporate quickly enough. so the cranking AFR (look at OLFA as well) is really really rich, for the very pupose of generating enough fumes to start it up, when the engine is cold.
when engine is cold, so is the gas. since you don't really burn gas itself, but its fumes, the gas has to be up to certain temperature to evaporate quickly enough. so the cranking AFR (look at OLFA as well) is really really rich, for the very pupose of generating enough fumes to start it up, when the engine is cold.
OK, makes sense but.........
My VE table is tuned for about 14.3 in the lower idle/cruise regions. On cold starts and when it's cold outside, I get black "water" coming out of the tail pipes and onto the driveway for a few minutes then it goes away.
This tells me that I have condisation in my pipes and that I am running rich on a cold start. The car start perfectly fine on cold starts. That is why I asked about Cranking VE.
I guess the main question is - How do I get rid on the black "water" on a cold start? I don't have cats.
#6
TECH Senior Member
iTrader: (25)
You can't get rid of the water, that what happens when you compress air. An engine is a big air compressor and when it is first started, it is still cold and is not generating enough heat to turn the water to steam. Once the engine warms up the water that is condensed out of the air in the engine is vaporizes and comes out of the tail pipe in the form of steam.
#7
Originally Posted by SmokingWS6
Cranking VE is just that, cranking. Rich conditions after startup are a result of the Afterstart Enrichment table. Think of it as a Choke on a carb'ed car. For most heads/cams car the stock values are to great, causing hard starts and very choppy idle after startup.
I'll have to check out the afterstart & OLFA tables. I know how to adjust the OLFA table, but how do you adjust the afterstart tables, just wing it?
My car starts up fine everytime on cold starts, pretty much like a stock car. I just get the black on the driveway.