dewmanshu

iTrader: (4)

SO for the longest time I have battled idling issues with my truck. I never doubted it was my tune. I suck with idling large cams (222/224). I have tried a hundred thousand things in my tune, hundreds of thousands I tell ya!!! I had my truck at work Friday and stopped by an auto shop to pay for a bill for one of our work trucks and I was sitting in the parking lot messing with my ve table. I was leaning out the high map low rpm areas. The next door shop is a scooby performance shop and I know the owner. I've done some electrical work in his shop, brought it up to fire code and put some high bay lighting in it. Well he hears my truck and comes out. We talk for about a half an hour trying different things. He's a professional tuner on scoobies and he's just getting all excited about how we can't get it to idle. He swear my afr gauge is wrong, it sounds like it is lean but my gauge shows 14 to 16. He makes me come over to his shop so he can tail pipe test it as well. He plugs in and says, "Holy ****, your voltage is 12.5!!!. Do you have an injector latency table?" It was like he threw a rock at me. Of course I do, "Injector Offset table". DAMMIT. MY voltage has been all over the place forever. After I start thinking about it, my air conditioner problems...if any of you remember, when at idle the ac wouldn't work, I have to be moving and giving it throttle...well DUH, I am revving the engine to give me more voltage to close the relay. WELL DAMMIT!!!! Ofcourse idle sucks, the offset table isn't tuned for 12.5 volts.

Now I just need to figure out what is causing all of this. At idle the alternator says 13.9 volts, the battery says 13.6ish, and in the cab my scanner says 12.5. Where is the loss?

I thought for the ones that know me, you'd find this funny sorta...it can't idle because the injector offset table has only been tuned in the 13.5volt area. LMAO sigh

95 bright teal

Dont you hate stupid stuff like that, its always so simple you overlook it for bigger things!

Well i hope you can get that voltage were it needs to be, ive been through crap like that, its never fun

KySilverado

iTrader: (7)

Makes sense. I'm not going to make a guess at the voltage drop. I've seen your wiring skills
Guess you need to see what voltage the actual injectors are seeing to make a decision on what voltage line to tune?

dewmanshu

iTrader: (4)

yeah...not excited about it at all. I think I am gonna throw a larger alternator at it first, just see if it makes a difference. I have a reman 105 on there now.

yeah yeah yeah

03sierraslt

iTrader: (22)

Cough, Cough.... I do recall saying somthing about tuning from 11.5v to 15 to cover all basics............... Glad to see you found it Dewey. So where the hell is the 1v going to.

XLR8NSS

iTrader: (4)

sigh..

dewmanshu

iTrader: (4)

You know..I do recall you saying that now. Good on ya...see, you have to grab me by the collar and make me listen!!!!


At least it wasn't that freaking 6 dimensional VE theory crap you had going. I could swear you were a geek in school...****, still are.

MikeGyver

iTrader: (5)

Everybody else on the internet (I of course mean me) don't fully understand this thread, but we (I) think we have the same problem. Is the point that the voltage is different at the scanner and the battery, or do you have a blank area on the 12.5 volt line in the offset table? Or does everybody need to tune their offset table? Is this in my help section?

dewmanshu

iTrader: (4)

The voltage on your scanner (Use a PID NOT the reading at the bottom of the screen) is what I'd imagine the PCM is using for calculations against your injector timing. dc_justin may elaborate more, as he is a logarithm and may be able to relate better.

Most truck guys, I am guessing are in the 13.9 to 14.2 volt range. I am sure you know, if not now you do, the PCM "blends" between rows and columns. So you are never really in one row. That's why tuning your VE can be an art soemtimes more than a specific job. So imagine this ball buster of a table. You keep screwing with only one voltage row get it all worked out and then a few months down the road you lose voltage (for whatever reason) and your tune is all off now. Besides fixing your electrical problem, you should come to this table and dial your VE back in with adjustments to your new voltage.

Again, you should be in the very high 13's/very low 14's from my understanding at all times.

As you can see below, I tuned the 13.5volt row, and then just hit the lower voltages with a large increase to be safe until I get my **** figured out.

MikeGyver

iTrader: (5)

You're going to have to use a longer drill bit to get through my skull. This is what I imagine the table is for: If, at 55 kPa and 13.5 volts your A/F is perfect, and then, at 55 kPa your voltage drops, and the A/F goes lean, then you try to richen it using a higher offset number? If that is correct, then what were you doing in the offset table, if you were only using one voltage? (horizontal) Wouldn't it be better to adjust for one kPa? (vertical) And then multiply all the other kPa values by the same amount. I'm just trying to get this straight, thanks for explaining.