ok so I finally have my car back from pauls, and I still have some logs to take, but I figured I'd post these first few questions to get the ball rolling. logged warmed up idle. 0.00 volts. lean, right? the o2 fuel trim works its way up to 199% as i let the clutch out and it aproaches idle. once it hits idle it goes to 100%. My guess is that this is because the 02 is telling the ecu that fuel MUST be added enough. It doesnt need the fuel trims to tell it that.

the only thing is, paul said he can smell my car running rich before i left. personally im sick so i havent used my nose in days. should I follow the logs, or paul? In order to get my car to pauls I turned the base knob up to 8, and now it sits at 5 I believe. should I turn it to 450cc injectors and use the idle, mid, and wot knobs to tune them, or should I leave the base and just tune. I know it "doesn't matter" since any fuel you add with the base, you can remove with each individual knob, so is there any point to changing the base knob after putting it at 450cc injectors?

on the way back i made all these second and third gear pulls, along with crusing at 65 and 45. all the stuff you need to tune. then, when I got to nations, where I had planned on eating/ analizing my logs, I realised that while I plugged my logger into my hotsynic wire, I forgot to plug the hotsynic wire into the datacable. sweet.......

more logs to come this weekend. any suggestions on what I should add to the list of logs for tuning would be great.

current list:
cruise at 45 and 65
2nd and 3rd gear pulls
idle when warm

Sounds like your O2 sensor is shot. I would go pick up another one from the dealer. I'm actually suprised that you don't have a FT CEL.

It smells rich because the O2 sensor is telling the ECU the car is lean, when it really isn't. The ECU then increases the amount of fuel delivered and creates a rich condition. Although the car is running pig rich, the ECU doesn't know it and keeps adding fuel.

The only log we need for tuning is a 3rd gear pull from about 2.5k to redline. Log knock, timing and rpm.

wait, so to set my fuel trims, the only log I need is a wot pull in 3rd gear from 2.5k to redline? hmmmm....

ive had the o2 sensor read correctly, so I dont think its shot. I cant smell and I think it was just the fact that we were inside a garage that he thought it was rich. Who knows. It goes up every once in a while, as if its just running really lean. one thing I noticed while reading the logs is that whenever the injector duty cycle was less than about 3%, the car was running lean. aka 0.00 volts. whenever it was higher than about 3%, the o2 volts would go up. same thing goes with the tps and maf logs. of corse the only log I currently have is me driving home from nations. aproximently 4 minutes. should I bother with cranking up the idle to really rich and seeing if the o2 changes?

cant do any logging til I bleed my clutch lines, she refuses to go into reverse without grinding. also want to drain and change all fluids in the whole car, since they were sitting for so long.

side note: throught out the log my low, mid, and high trims sat at 118%, 100%, and 97.6% respectively. peak tps was 38.6%

how often/much do you have to change wot trims when you change the boost. I think the only thing that would change it much would be if you go from under 70ish% idc to over 80%

You want your trims fairly close to 100%. Your low trim is running slightly lean, but that is not a huge deal. All I had to do was set my MAFT up to 450cc injectors (assuming you have the stock injectors) and let everything else stay zeroed out. Car ran fine and only had a little bit of knock ( I had a boost leak) around 3-4k rpm in 2nd and 3rd gear. I turned the mid one click richer and it ran fine. Now it is all zeroed out and no knock and pulls hard. I would set it to the injectors you have and leave it zeroed out, then do some logs and tune it for no knock and reasonable fuel trims at the boost level you will be running most of the time.

the only thing is that all the logs are telling me that im running lean, and setting it to 450cc injectors and zeroing everything out would involve leaning it out even more.

If you are saying what I think you are, then turning up the base knob is telling your car that you have larger injectors, which in turn would cause the car to inject less fuel than it would stock. If you had larger injectors, then they would not need to spray as much fuel to compensate for the same amount of air as would smaller injectors. What I would try is write down your settings that you have now and just try setting it all to stock and zeroing it out. If you dont feel very comfortable doing that, then you could richen up your mid and high's just to be on the safe side. Either way, write down your settings if you decide to change them and it doesn't work out how you thought.

everything is zeroed out, except for the base knob which is at 5 or 4. stock is 2. I agree with your logic, but for some reason, when I turned the base knob up, it ran better when I had a HUGE leak. at the stock injectors the car would not start without 100% wot. with the base knob at 5 it would start but would not idle properly. with the base knob at 8 it ran and idled fine for a car reading 10 hg/in at idle. drove it to pauls and he fixed the leak (long story). then when I tried starting it with the fixed leak, it started but died after a few seconds. took it down to 6, it did better but still died. took it down to 5 and it did fine. can't remember if after that I turned it down one more click to be safe or not. so its at 5 or 4 right now. I guess I'll just do what the damn instructions say. its probably good enough.

tstkl said:

wait, so to set my fuel trims, the only log I need is a wot pull in 3rd gear from 2.5k to redline? hmmmm....

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I think you misunderstood my post. FT's are only used at cruise / idle conditions. At WOT the ECU could care less about O2 voltage and FT's. I ment that for tuning purposes, we only need a WOT log. FT's are something that you have to sit in the driveway and screw around with.

This might help:

http://www.racingknowledge.org/ver3/viewtopic.php?t=1011

Also, in one of your posts, you state that your peak TPS was 36%. That wasn't at WOT was it?

Just because your O2 reads correct some times, doesn't mean that it's not almost dead. Mine got beat with a hammer (by a vendor who shall remain nameless) and would give "normal" reading every once in awhile, but I still ended up with maxed out FT's.

tstkl said:

everything is zeroed out, except for the base knob which is at 5 or 4. stock is 2. I agree with your logic, but for some reason, when I turned the base knob up, it ran better when I had a HUGE leak. at the stock injectors the car would not start without 100% wot. with the base knob at 5 it would start but would not idle properly. with the base knob at 8 it ran and idled fine for a car reading 10 hg/in at idle. drove it to pauls and he fixed the leak (long story). then when I tried starting it with the fixed leak, it started but died after a few seconds. took it down to 6, it did better but still died. took it down to 5 and it did fine. can't remember if after that I turned it down one more click to be safe or not. so its at 5 or 4 right now. I guess I'll just do what the damn instructions say. its probably good enough.

Click to expand...

The car ran better with it compensated for larger injectors (turned up to 8) when you had the huge boost leak because you were telling the car to inject less fuel. With less fuel being injected and less air due to a boost leak, then it was running closer to an ideal air/fuel ratio and that is why it seemed to run better. With the stock fuel settings and a huge boost leak it would be running very rich, but because you told it you had larger injectors, it injected less fuel and made the car run better despite the boost leak. If you have done a boost leak test and are sure that you have no leaks, then try the stock settings, like I said before, it wouldn't hurt to try them and if it doesn't work out, set them back to what they were before.

the leak was at the intake manifold and caused the car to suck in unmetered air. it needed more fuel to compensate. I have no idea why it ran better.

did a third gear pull after bleeding the clutch fluid, seafoaming, and changing the oil to full synthetic (should i go easy on it? wasnt synthetic before)

hit fuel cut three times. 10 psi of boost. no idea why. idc was at 96%, maf read 1599 hz (max), tps read 99.6%, 20 counts of knock with many other counts throughout the run. (warmed up the car and drove it around for about 20 minutes. timing was obviously low.

more when i get home...

how do I get my log on my computer?

now the base is at 2 (450cc injectors) and the idle is at 1 (plus 5%).

tstkl said:

snip...logged warmed up idle. 0.00 volts. lean, right? the o2 fuel trim works its way up to 199% as i let the clutch out and it aproaches idle. once it hits idle it goes to 100%. My guess is that this is because...
snip
...the only thing is, paul said he can smell my car running rich...

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It is rich. When the trim instantly changes from 199% to 100% that means the ecu gave up trying to use trims and switched to limp mode. It's either a big boost leak, or it's time to change the caps in your ECU.

You're hitting fuel cut because you have a big bost leak, or you're adding too much fuel (increasing the airflow signal) with the MAFT.

In the 1990 ecu the lo/mid/hi trims have a range of 81% to 118%, so 118% is maxed out.

A boost leak will make the car run lean when under vacuum, and rich when hitting the boost. That's why your trims look that way. So adjust the MAFT rich at idle/lo throttle, and leaner at WOT. And fix the boost leak.

the boost leak was fixed, maybe? it is possible there is still a leak, but I have no way of checking. (no compressed air) I just paid paul 100 bucks to fix the leak at the intake manifold so I hope it is fixed. I'll call him tomorrow and see what he thinks. its not his fault, its the god damn dealer....

After setting my settings to stock and I was almost positive I had a decent boost leak, I went out and logged the car and it got 5 counts of knock. I fixed the leak (bad coupler) and then everything was perfect. To get a log to your computer you need to hotsync your palm with you computer using your cradle or something and connecting it to the computer. It will put the log in some file somewhere that you will have to find.

i did some wot pulls on the way back from pauls and did not hit fuel cut, but now that I've changed from these settings:
480cc injector setting, 0% idle, 0% mid, 0%wot
to:
450cc injector setting, 5% idle, 0%mid, 0%wot

I hit fuel cut at like 3500 rpm's, maybe a boost leak formed in the time between the two pulls. (first was wednesday, seccond was last night)

found the file, how do I veiw it?

I'm about to go check the vacume at idle then go watch my friends suspension install

Here is a link to the software you need to download to view it.

http://www.pocketlogger.com/index.php?pid=utilities

vac is -15.5 to -16 with hood open, but read -17 with hood closed. hotter air is less dense?

just seafoamed her, changed the oil, and power steering fluid. and this whole time I thought it was just that my dsm had weak power steering from the start. buy the expensive stuff and youll be using one finger to turn your steering wheel just like me.

anyone think that I could actually be hitting fuel cut due to my free flowing intake and exhaust? its running 10 lbs last time I checked.

No, I don't think you're hitting fuel cut from your mods at 10psi. There's something else going on. If it's not from a big boost leak, it could be a misfire from running very rich.

When you view the logs, check O2 volts to see if there are any downward spikes, like the volts go from rich to almost zero and back up quickly. Then look at the injector duty cycle to see if it also has an erratic reading at the same time. During a WOT pull the inj DC should be smooth. Fuel cut will show a downward spike in the O2 volts and inj DC goes to zero, while airflow Hz will gradually decrease. Rich misfire wil have the O2 volts spike downward but the inj DC will stay up. Also check inj DC to see if it goes above 100%. Sometimes the injectors will spaz as they go over 100% and cause a hesitation/misfire similar to fuel cut, but not as harsh.

vac seems ok, so its not a leak at the manifold (where the original huge leak was)

I'm hitting 1600 hz, so it is fuel cut, but it could be running rich.

o2 volts do have downward spikes, going from .93 to 0.00 very quickly, idc goes from 94.5% to 0% at the same time.

airflow DOES NOT decrease until I backed off the throttle. idc does not go above 100%

what I noticed: timing hit 45degrees after I started letting off, isnt that a little high?
lot of knock, 20 counts.

also, I added 30% fuel at idle and now its good. whats funny is paul told me over the phone that with every car he has tuned with a maft, he has had to add like 30% to the idle to get it to run properly. maybe its that I'm at sea level almost, who knows.

how do I post my logs? that plveiwer didn't really work

I want to try and lean it out at wot, but I would want a wideband o2 to know what my actual afr is. or an egt gauge to make sure I dont go overly lean. also, if I lean it out so it works at 10psi, when I kick it up to 20psi whats going to happen? I have a vr4 fuel pump, will that help in any way? its not installed right now.

The only way I've been able to post logs is witht he PocketLogger Viewer thing. You have to make sure it saves the file as a .jar not whatever it tries to save it as. Then it will open if you have the right version of javascript. It is a really neat program and I recommend it.

I did, but I cant find the files with it.

thats not whats important anyways, look at my previous post. ignore the stuff about plveiwer

last year when I was running the car completely stock minus a mbc at 17 psi my logs show 1593hz on one pull where I didnt even go wot. I was at 87.8% tps. on another log I hit 1600hz and it stayed there for as long as I held the throttle. there was no fuel cut that time. now that my intake flows a lot more, is it hard to believe that since I have a decent intercooler, but the same fuel system, that I'm hitting fuel cut? How do people with much larger turbos at much higher psi get around fuel cut. they have to be flowing more air than I am and they can't just lean it out until it shows less than 1600

could it be that the gas is really crappy since its california spec 91 octane thats been sitting since august?

From personal experience, I had gas just sitting around for a month and when I first logged the car I was getting 5 counts of knock only on partial throttle. I refilled it all up with 93 and adjusted the settings just a tiny tweak and no more knock. Not sure if new gas does anything or not?

well I think the question is, does the ecu bump up the airflow for lower octane, assuming that the age of the gas caused it to lower its octane level.

ECU has know way of knowing the octane level, but apparently it says use premium fuel only, so it assumes that it is something like 91-93 I guess.

tstkl said:

well I think the question is, does the ecu bump up the airflow for lower octane, assuming that the age of the gas caused it to lower its octane level.

Click to expand...

That's a wierd question, the airflow signal comes from the MAF. Fuelcut is triggered by high airflow. The ECU doesn't know what fuel pump you have, so a good pump will not affect fuelcut. If the octane is low the ECU will retard the timing, and if you still have the stock BCS the ECU will trigger it to lower the boost.

You can get around fuel cut by getting bigger injectors. With it, you will have to lean out the settings on the MAFT to compensate, so the ECU won't see as much airflow signal coming through.

Thanks for answering the other question. Something else to look for: do you get much knock before fuelcut? Fuelcut can trigger knock. I've also seen several DSM's that show knock increase just as you back off the throttle, I don't worry about it then. If your knock is zero during a clean pull there may be room to lean it out slightly and see if fuelcut goes away. You don't need a wideband yet, just monitor knock as you tune and make sure it doesn't get out of control. I have my Pocketlogger set up to beep if knock goes over 15 counts. That way I can back off right away and check the logs to see what happened.

Yes, 40 degrees of timing is OK at low airflow levels. The VR4 fuel pump is a good pump, I'd install it when you get bigger injectors.

alex99gst said:

ECU has no way of knowing the octane level, but apparently it says use premium fuel only, so it assumes that it is something like 91-93 I guess.

Click to expand...

The ECU can tell the octane by how much knock it's seeing, so it lowers timing until knock goes away, or until it can't pull out anymore timing.