Re: tune is very inconsistent could big injectors be the problem?
 

nice, good idea thanks.

Re: tune is very inconsistent could big injectors be the problem?
 

that is sweet

Re: tune is very inconsistent could big injectors be the problem?
 

this may not be it but...in tuning some vw 4cyl turbo cars recently we found that with larger injectors, more spark is a HUGE benefit. we upgraded the stock ICM to the Mallory 6a with crane cams high output coil and it fixed the inconsistant AF ratios and allowed the cars to work very well..good luck man

Re: tune is very inconsistent could big injectors be the problem?
 

I got it figured out, I didnt change the battery offsets at all, just pulled fuel until it worked.

Re: tune is very inconsistent could big injectors be the problem?
 

Just an FYI, there is a script for Crome with injector offset tables for many after market injectors.

Good to hear you got it fixed.

BTW. Were you runningi open loop or closed loop with the inconsistency?

Re: tune is very inconsistent could big injectors be the problem?
 

I was running open loop, its still acting up but not as bad.

I know about that script for the injector offset tables I was reading about it on pgmfi, but I cant find where to download it

Re: tune is very inconsistent could big injectors be the problem?
 

Datalogging battery voltage is the way to tune the injector battery tables. If Crome doesn't support that yet, use a multimeter hooked up to the power pins on the ECU.

Turn on your headlights. Turn on your blower fan. Turn on your turn signals. Rev the motor up. Let it idle. Choke the motor to drop the idle even more.

Adjust the battery offset tables in order to get your AFRs to even out. Most of the time, you will be adding units to 10v, 12, 13.0v and significantly less adjustment at 14v and above.

I've yet to see any script with perfect battery offsets. Things like fuel pump, how pump is wired, battery being in trunk, which resistor box / inline resistors, etc. can make a huge difference.

Re: tune is very inconsistent could big injectors be the problem?
 

Thanks you very much for that Blunder.

:y

Re: tune is very inconsistent could big injectors be the problem?
 

I've noticed the exact same problem with my tune. I will be playing with the injector offset tables...

Re: tune is very inconsistent could big injectors be the problem?
 

Thank you very much for that, I've read that the best was is like you said.....use a multimeter but the whole reason for that is to find the exact pulse width at those certain voltages right? I've read dozens of threads on pgmfi suggesting the mutlimeter but I dont fully understand what i'm looking for, but you'd think that the company (precision) would know those exact pulst widths for there injectors at those voltages, but I guess like you said there could be alot of things affecting that.

So lets say I was going to start with the 10v, I just turn on accessories until I see 10v on the multimeter, correct? and then look at the pulse width in the datalogging window in crome, correct? and put that value under the 10v in the battery offset table, correct? then to do say the 12v turn off accessories until I get 12v across the pins on the mutlimeter and repeat the process, correct? Or am I all wrong, lol. I'll keep searching either way. The car has been put away for the winter, I will be pulling the motor breaking it down and checking it all out, maybe sleeve it. This is all great info thanks!!