mguidry629

iTrader: (6)

Finally got my motor swap completed and got the camaro back on the road. Here's the short version: 93 Z28 car. Pulled motor, harness, pcm, etc from 95 Z28. Tore motor down and completely rebuilt 383ci short block, ported stock heads, custom ground small base comp cam, rockers(1.52), springs, lifters, cai, lt headers, agr and air delete, and a few things I'm forgetting.

Let me just say that I'm a newby to tuning, but I've been researching and playing with TunerCat for about 6 weeks, so that when the time came to tune, I would be ready. (I understand it takes longer to learn everything, and I know some will say "you don't need to be tuning", but you gotta start somewhere)

1st turn of the key and the motor fired right up on stock tune with open headers. Finished up all the details and test drove with open headers. Car warmed up and developed a misfire or something similar.

Next day, installed full exhaust (no cat). Tuned a few basic things in the switch table and constants table of TunerCat. Increased main timing tables by 2 degrees across the board.

Time to log (FreeScan), so we took a ride. 1st log was from cold start. No problems at all, maybe a little knock here and there. Speedo was off, so we pulled over and tuned it. Cranked it back up and hit the road again (warm start). Motor started bogging down as if not enough gas or misfiring. This happened sporatically through out the second log, but motor stayed running. Constant knock retard throughout 2nd log up to 13* if I remember.

Next day, same thing. Cold start, ran great, even after it reached normal temp, but cut the motor off and back on and ran like poo. I started thinking maybe this is something to do with being in closed loop, so I tuned the pcm to stay in open loop and car is running great now.

In summary, runs like poo from hot start in closed loop, runs great in open loop all the time. Drove to 23 miles to work this morning in open loop.

My first thought is O2 sensors. I figured I should replace them from the beginning, but I didn't have problems with the old ones, so I figured I would try them out before I invested in new ones. What do you think could be causing the problem? If o2 sensors, which ones should I get?

I have many other questions, mainly about interpreting the data logging spreadsheets. What's O2 voltage supposed to be? My left is at 1.101 and right is 0.284 when at warm start idle, but then it varies from there throughout the log, they both get close to .7 at one time, then right goes low again, etc.

How do you interpret the MAP reading. Is 1.00 100kpa? and .50 would be 50kpa? How is air flow measured? What is knock count and how does it relate to knock retard?

I know it sounds like I know nothing, but I'm really just trying to get 2nd opinions, so I have to ask the dumb questions too.

One last question...How do I change the desired idle rpm? The motor a little too lopey sitting at a red light at 600 idle. I would like to bump up to 800-900 all the time. Trans is 4L60E.

If anyone has a similar setup, can you share some of your tables with me?

gregrob

iTrader: (8)

Your 02 readings are severely screwed up. That's why it runs like crap in closed loop...
Figure out what is causing them to read so weird. 1.1 is maxed out, possible stuck injector on that side, 200 is almost no fuel. Could be jnust screwed up O2s or extensions.
If you have no wide band shoot for low 900s on the o2 mv.

Why did you just arbitrarily add 2 degrees? There's every chance that your enginecould actually need less timing than stock in a lot of areas.. esp if its high compression, small chamber heads, etc

What are the cam specs, scr, dcr?

You could be getting false knock. Do you have a lt4 knock module. Put 5 gals of race gas in and tune ut the knock

What are your FUEL TRIMS doing at idle?

Get the O2s reading correctly and then tune idle only, then light cruising, etc...

gregrob

iTrader: (8)

I would also suggest getting a mail order tune and using that as a STARTING POINT

mguidry629

iTrader: (6)

OK, compression is stock, same with head chamber. Cam is 220/228 @.50 114 lobe sep, .510 lift. I haven't had a chance to log it since I switched to open loop, but I'm thinking my FPR may be having problems and it's running lean. Would that cause the O2 readings to be screwed up like they are? Those O2 readings is what gives you the AFR? 200 is very lean and 1.1 is very rich? Looking through my previous logs, the readings vary alot, but average around 600.

gregrob

iTrader: (8)

Yes 200 would be considered very lean and 1.1 very rich.

Look at what the BLM's are doing, they will probably reflect the huge difference in the 02's by trying to correct each side much differently.

You want to shoot for Long term fuel trims of as close to 128 as you can get.

My95Z

iTrader: (8)

It would probably help if you could get the log up so we could see it. You should see your O2 voltage jumping all over the place when not in PE, that just means they are working good. If they seem to stay in one area they are probably bad or like mentioned above something is messed up with the wiring.

A base tune would probably be a good idea, it would let you see what things need to be changed from a stock tune and give you a better idea of what actually does what.

And to answer your question the "IAC Target RPM vs Coolant Temp vs Gear" table will adjust your idle speed.

mguidry629

iTrader: (6)

Just took 2 logs. 1st is open loop, 2nd is closed loop. Car ran good both times. I adjusted all my timing tables since my original post and prior to my logs.

The logs are .csv and open in excel. I converted to .xls, but I guess ls1tech won't allow either to be attached to this post. If converted to a pdf, but it gets all screwed up trying to read that. Any suggestions on how I can get them on here? How do you guys usually view your logs? excel?

The O2 readings are bouncing all over, but the right side is consistently lower and sometimes down to 200. Which is changing BLM on right side. At WOT the readings look alot better than cruising.

I will try to post the logs tomorrow. Thanks for the help.

mguidry629

iTrader: (6)

I changed all the timing tables dramatically in some areas, increasing and decreasing as needed prior to my logs last night. I've reviewed both logs, and I'm getting no knock anymore. Car seems to be running great in closed loop and making much more power than the last few days. I made a couple WOT runs up to about 65MPH, but mostly just cruised around at 45-50MPH. Here are some of averages of the closed loop log:

MPH: 32.38
O2 Left: 0.686
O2 Right: 0.557
BLM Cell: 12.88
BLM Left/Right: 124.03/133.77
Integrator Left/Right: 126.88 / 128.49
MAP: 0.495
TPS: 8.43
Spark Advance: 34.90
MAT: 31.66*C

These are just the averages of the respective columns. Anything look way off? Does anyone have an answer to my question above about attaching the log file to this thread? Or does anyone even care to view them and give me some advice?

brucer

not sure in tunercats, but you could install tunerproRT ver.5 beta and export your log file as an .html file.. the site might handle an html file, you might need to host it off site dont know never tried it..

My95Z

iTrader: (8)

TunerCats doesn't do any logging, its all programming only, he was using FreeScan.

Normally you have to use a file sharing/hosting website and load the .csv file onto it.