jonarotz

iTrader: (26)

Here is my new setup:
355 forged flat top pistons, ported & polished ZZ4 heads, 24 lb injectors, HSR, 58mm 1000 cfm throttle body, &comp cam with following specs:
Duration @.050 Int-230 Ex-236
Lift Int-510 Ex-520 lsa 114
4 degrees advance ground into cam.

I am using a 730, 8D. I am currently using the super AUJP_3 bin. I have found that I need to take quite a bit of fuel out in the idle range (~65kpa) range. I started trying to nail the idle down in open loop, see where the O2 votages are at, adjust the swing points, and let it go into closed loop. I got the thing to idle somewhat decent, but when I put it into gear it accelerates like crap! I have the dist. set at 10 deg. and have put that in the bin.

Does anyone have any ideas that might make this a little easier to tune?

DENN_SHAH

iTrader: (1)

any time i work on a motor that has been cammed, i like to get the best idle timing before i do anything else.
if you have an adjustable advance type timing light it makes this much easier to do.
with the motor warmed up, unplug the timing set connector & turn the distributor to find the best idle/highest vacuum readings. now see where the timing is set at. set the timing back to base & set the timing in the chip so you have it where it idled the best at.
you can also do this in neutral at 1000, 1500, & 2000 RPM to get an ideal of what the motor wants.

if your using the factory O2 sensor, it will be hard to get the fuel right with it.
with that cam, you may need to set it up so it idles in open loop.

if you haven't already, read through this, it may help you out some,
https://www.thirdgen.org/forums/diy-...ecm-large.html

jonarotz

iTrader: (26)

Thanks for the advice! I will try the timing thing. When you say to set the chip to the best timing achieved...do you mean in the main spark table or the actual dist. setting constant?

DENN_SHAH

iTrader: (1)

i can never remember if the ECM adds base + the main spark table to equal total timing, or if the main spark table includes the base, it seems i always have to read up on it every time i mess with my timing, one day maybe it will stick in my mind
i'll try to explain it & maybe you'll understand what i mean.

with the timing connector unplugged, say you turned the distributor & found the best idle at 32 degrees at 800 RPM & was in the 50 kpa area.
you want your base timing at 10. a base setting of 10 in the chip minus 32 is 22. you go to the main spark table & in 50 kpa 800 RPM you set it to 22, so when you start the motor up & put the timing light on it, it shows 32 degrees at 800 RPM.
did this make any sense to you? it doesn't to me

Z69

The 8D,6E main/extended SA tables show what you will see if you used a timing light. Except for startup, coolant compensation, PE, idle error etc. The base setting is subtracted prior to the SA being output to the distributor.

Setting the idle speed up will help with the idle also.
What did you end up with for swing points?

jonarotz

iTrader: (26)

Yeah I think I understand. Thanks!
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I can get it to idle pretty decent at about 800. my swing points are high im my opinion...7.5-8mV range.

JP86SS

iTrader: (1)

I'd help you but then you might be faster than me around here!
Really though, once you get the richness at idle taken care of reset your IAC/TPS so you only get 20-30 counts on the IAC.
Work on confirming you are not falsly rich from overlap (o2 constants) and play with TPS MAP settings.
Might want to compare the V2 settings to the V3 on the throttle follower stuff. Mine works better with a combination of the two but slightly more towards the V2 settings. I have a 52mm so your 58 may react differently.

jonarotz

iTrader: (26)

LOL...thanks. I am going to get the timing down by using DENN_SHAH's method tonight. Then I will shoot for the fueling gremlins. Thanks for all your advice.

jonarotz

iTrader: (26)

The timing tip helped out. I was able to get it to idle with 13in of vacuum and it seemed to have better throttle response too. Now I just need to get the fuel squared away. I am getting closer. I logged a little idling if someone would please look at it and let me know what they think I would greatly appreciate it.

DENN_SHAH

iTrader: (1)

glad the timing tip worked.

thank you Z69 for posting how the timing works

JP86SS & Z69 are at a level way over me.
with the cam you have, i probably won't be much good, but i can take a look to see if i notice anything.

jonarotz

iTrader: (26)

I am at work now and don't have the datlog file on me. I will try to get it on later.
I did notice that it idles at 800rpm and 55-60kpa, but the iac is about 100 counts. What would be the best way to get the iac down to the previously reccomended 20-30 counts?

JP86SS

iTrader: (1)

Your idle is exactly like mine. Nothing good below 800 RPM.
Adjust your mechanical stop to open up the throttle blades a bit more.
The counts will drop as you do this.
Once you have the counts good, then go back and do the TPS volts for idle again.

jonarotz

iTrader: (26)

I played around with the fueling tonight and I actually got it pretty decent. I am waiting on my new plates so I can log some road speeds and different loads. I will try to adjust the blades and get the IAC steps down.
Thanks for your help guys!

jonarotz

iTrader: (26)

I got my iac counts down to 20-30 but I noticed that I had a huge flare up in idle speed as the rpms came back down from a half throttle stab. I lowered the iac park position and it seemed to go away. I drove it around the block and it seemed to run pretty well in closed loop. I still have quite a bit of tuning left but I am surprised how good it actually ran.

Z69

See this also
https://www.thirdgen.org/forums/diy-prom/412181-730-cold-spark-advance.html

By swing points I should have said what mv are these set to?
They are explained in the o2 constants stickies.

Idle O2 Rich/Lean Slow Zero Error Lower
Idle O2 Rich/Lean Slow Zero Error Upper
Idle O2 Rich/Lean Threshold Fast

jonarotz

iTrader: (26)

Sent you a message.

DENN_SHAH

iTrader: (1)

i didn't get it, try to resend it

jonarotz

iTrader: (26)

Looking back at my datalogs I see a lot of areas where the O2 voltage drops to zero volts. There doesn't seem to be any rhyme or reason for it like DFCO or anything. Can someone look at my log and offer any advice?

DENN_SHAH

iTrader: (1)

so we are on the same page, send me the bin that you were running when you make that log.

escort_ford84

DENN_SHAH, i couldnt help but notice your runnin 2.42's with the 700-r4. I think thats really something. I went from 2.73's to 3.42's, and kinda thought it ran a tad better with the 2.73's. I had a chance to get some 2.56's, but now that i think about it, i may try to get those 2.56's back. Do oyu like those gears?

DENN_SHAH

iTrader: (1)

its ok, but from a dead stop its somewhat sluggish.
its been good enough for a 2.2 60 foot, 10.05 1/8 with lots of tire spin & a bad fuel pump. now with the good fuel pump & if i had a posi, i think i could do 9.5 in the 1/8 mile, i got old so im not into drag racing much anymore.
it freaks people out when im at 75 MPH & nail it & it drops to second gear, if i had a mini ram on it i could probably run to 120+ in second gear.
im not sure if the high gear is hurting me on fuel mileage, i turn about 1500 RPM at 70 MPH in overdrive.

escort_ford84

Awsome

jonarotz

iTrader: (26)

Well I got my plates and now I am fully insured. I drove it about 20 miles tonight. It doesn't run to bad but I did notice a couple things. Under very light throttle like just off idle I notice it seems to surge/stumble. I am thinking a lean condition since I have a 58mm tb. I have a autometer afr gauge, I know pretty pointless but I like the pretty lights. Anyways, it never seems to go to the rich side. most of the time it idles and cruises on the richer side of stoich but never really into the green. Until I get my O2 bung welded into the new y-pipe and get my wideband hooked up this is all I have to go by. I am going to try to increse the pump shot and ae scaler to help remedy some of the off idle stumble. I am also going to try richening up the VE and see where that gets me. What do you guys think?

DENN_SHAH

iTrader: (1)

i looked at your data log a few minutes ago, i just sent you an email on it.
you are rich in a lot of areas, but your very lean in an important area, it looks like those injectors may not be big enough.
7.8 mSec at what looks to be 25% throttle.

jonarotz

iTrader: (26)

Thanks for looking at the log I appreciate your help.