VORTECFCAR

iTrader: (2)

Everyone says it's cool, dont worry about it. I wasn't worried about it until I logged it and got KR at full throttle.

Too much timing....? 19 degrees

Not enough fuel...? narrow band reads mid 900's
PE table
1.237 1.24 1.245 1.288 1.297 1.323 1.378 1.378 1.378 1.378 1.378 1.378 1.378 1.378 1.378 1.378 1.378 1.378 1.378

Whats the deal?

Am I running out of injector? Fuel filter?

I guess I'm just looking for directions... I can feel this thing pull timing...Im ready to dump a gallon of Xylene it .... or on it.

I can email scans or tunes to anyone willing to help.

thanks for reading

edit for mods and question... How do you log injector duty cycle? I dont see in my chart options menu for HPT. I only see pulse width and flow rate.

346 LS1
PP LS6 style heads 58cc
231/237 TSP cam 112 LSA
Kooks 1-7/8ths -X pipe-dumped

LoWeLL216

iTrader: (1)

I'm assuming your using HP Tuners 2.xx It's in the default config. Just look on your chart display. (you don't directly log duty cycle, it's calculated)

VORTECFCAR

iTrader: (2)

I'm trying to download version 2.1X right now, but the guy who sold me the cable didn't give me his password to login. So I just had his password sent to his account....dammit.

ARRRGGHH!!!


EDIT: doing some reading on HPT forums and came across a solid post by jimmyblue, I'm wondering if maybe my header extension pipe is hitting the floor and causing false KR....hmmm. If it's real detonation I should be able to hear it right? I just dont want to frag this motor.

ringram

Many things will pull timing, burst knock is notorious as is the shocking knock settings on earlier models such as your 98.
Check out the knock settings on a late model camaro. You might want to adjust BKR and Knock sensitivity.
Sometimes you might not hear knock, but usually you do.
Also look at the shape of the KR over time, if its ragged it shows sustained knock, which is bad. A little spike here and there might mean false knock.
You will have to experiment. Do a search for false knock and see what comes up.

cantdrv65

iTrader: (3)

Hmmm. If your narrowbands are reading mid 900s you are getting enough fuel. Mid 900s is somewhere in the 11:1 AFR range ......and 19 degress sure isnt much timing. Bad fuel?

VORTECFCAR

iTrader: (2)

thanks for the suggestions guys, I went to the global KR vs. RPM vs. MAP table and set the whole thing to 4.0. PROBLEM SOLVED.

I have the timing set fairly conservatively at 25 degrees and have readjusted my PE table back to the mid 12's:1.

anyone having similar issues, I suggest getting premium fuel or adding some high octane unleaded and log a run. If you have modest timing and good fuel, it's probably false KR - fairly common with modded '98 cars.

I did a couple WOT runs after desensitizing the sensors and I didn't get any KR or audible pinging.

Any thoughts or comments?

My90Iroc

iTrader: (26)

Make sure you're not masking a true problem. If you're on stock injectors you're probably at their limit.

VORTECFCAR

iTrader: (2)

thanks, hopefully I'll be able to log duty cycle soon and know for sure. Until then I'm just kind of taking it easy.

FWIW, I was getting KR as low as 3500 RPM - I think it's unlikely the stockers were out of fuel by then..?

have to get a racetronix setup and injectors in this thing next. $$$

RedHardSupra

iTrader: (1)

what kind of injectors you got to go with that big cam/exhaust?

VORTECFCAR

iTrader: (2)

Im running stockers right now, I'm thinking 42lb svo's should be plenty though - and maybe even enough for a small dry shot.

I went with the large primary headers and true duals because I got them for a good price used and wanted to be sure I had enough in case I ever went with more cubes or big juice. After a few days of tuning it's really running well.

Am I mistaken thinking that the 28.8lb injectors will feed this pig? I knew it would be close, I thought I'd be ok for a while. If HPT would buck up and help me out with version 2.X I could log my damn duty cycle and know for sure.

Is there any way I can manually convert pulse width to duty cycle... ? :goes to search:

Deeavi

iTrader: (16)

For insurance I put in a gallon of toluene at every fill up! 1 gal of toluene + 10 gal of 93 octane = 95 octane.

98redorangeta

iTrader: (10)

If your not going lean then injectors isnt the problem even if your going over 100% duty cycle and you need new injectors if your not lean then then thats not causing knock. 98s are bad about the knock sensors picking up false knock getting 99+ knock sensors sometimes helps.

VORTECFCAR

iTrader: (2)

there is no more knock, slightly desensitizing the sensors cleared that up.

98redorangeta

iTrader: (10)

Ok just thought i would let you know in case you didnt want to leave your knock sensors desensitised.

RedHardSupra

iTrader: (1)

yup, correct.

I went with the large primary headers and true duals because I got them for a good price used and wanted to be sure I had enough in case I ever went with more cubes or big juice. After a few days of tuning it's really running well.

28.8s are good for a bolton car and that's about it.
go to stickies, and there's a thread (started by me) about injector pulse width/duty. new HPT has injector duty cycle as a custom pid, so you can just display it,as long as you got injector pulse width and rpm selected as well. or if you just wanna revisit some old logs, export them to excel, make an extra column, and have a formula =max(injpw1:injpw2)*rpm/120000 and format it as %. then somewhere else have a =max() function on the column you just created, and that will display your max duty cycle.

VORTECFCAR

iTrader: (2)

looks like I was seeing 117% on my WOT runs, but that was at a 10.5:1 -11.1 AFR. I think I'll pony up for some 42lb'ers just the same. They're pretty reasonable.