Fixing my 95 Z28 after its been sitting for the last 11 years with a blown trans. I took a log with datamaster and got tunercat software. I put a 2000 stall converter in and right now all mods are CAI, 160 deg therm and all the free mods. I am new to the PCM tuning. Maybe someone can look at this data log and tell me if everything looks ok and if there and quirks. Also if you find something maybe some tips on what to tune? I just replaced the O2 sensors, resealed the intake manifold, rebuilt the trans and a bunch of other maintenance. PCM has stock programming. I have a Hypertech power Programmer + but took that out till I have everything correct. Would love to tune for MPG until winter is over.

Thanks in advance for any help.

z28log1.uni - 4shared.com - online file sharing and storage - download

 

I downloaded it and will take a look.

 

Thank you Fred! I really appreciate the help.

Wes

 

A quick run-through doesn't show any significant problems. It's pulling a little bit of fuel under low load/low rpm conditions, and adding a bit at higher loads. It would be useful to see a short period of idling to verify it is operating in the correct fuel correction cell. It would also be useful to see a wide open throttle pull, which puts it in "power enrichment" mode and shows how its running under max power conditions.

The barometric pressure looks low. I'm guessing that you are located about 3,000-ft above sea level? Confirm.

I'll take a closer look, but I'm going away for a couple days of vacation, back on Wednesday.

 

It sounds like your car is pretty much stock. Unless you really know how to tune, you will probablly make things worse. What are you getting for MPG? Replacing old and worn out parts is the best way to get better gas mileage. Things like the fuel filter are missed all the time and can cause issues if left to long.

 

Yes I live at exactly 2998 feet.

My idle is kinda rough. Not what I remember it being. I am kinda worried about a possible head gasket issue. I do get what looks like condensation out of the tail pipes at idle even when warm however its only 25 deg outside. The Coolant basically turned to rust in the car. I did the 2 part acid + neutralizer 3 hour flush and everything sparkles inside now. I replaced the plugged heater core and put a inline strainer to catch all the gunk. Still getting rust looking crap out. Dexcool is gone. Replaced with HOAT antifreeze.

I have done quite a bit of maintenance since taking it out of storage. Here is a list. Maybe you know of other things to look at.

Things done... Full transmission rebuild with stronger clutches and shift kit, All fluids (including engine oil (mobile 1 5-30), rear end, coolant, brake, power steering, transmission), fuel filter, new spark plugs, egr cleaned repair silnoid, intake manifold redone due to oil leak, all lines on evap system replaced due to rot/leaks/gas smell, both O2 sensors replaced, serpentine belt replaced, injectors soaked in a ultrasonic cleaner with techron, maf sensor cleaned, K&N air cleaner cleaned/oiled, new tires and I am sure I missed a bunch of other things.

I still am looking at possibly doing the cap/rotor (still original opti) and plug wires. Might have the injectors cleaned and flow tested as well.

Thanks guys for your help,
Wes

 

How many miles on the car and also since you did all the work? What did you do about the old fuel? The opti and connector could be in bad shape and might need to be replaced. I would be curious how it looks after sitting so long. I would definately think about a replacement or open it up and check it out, for sure if high miles. Might just need to be driven to work the kinks out. Fuel cleaner like Lucas will help clean the whole fuel system. Check the hoses and connectors for signs of rot and corrosion.

 

Car had 80,000 on it when parked. I was was started a few times in all those years it sat. It was moved around a bit as is was 3rd gear that was toast. The gas that was in it was basically empty when parked and it dried up. I filled the tank and put techron fuel system cleaner in it. Let it sit for a day and drove it till empty. Repairs have been over the about a 3 month span and I have since racked up another 1000 miles on it. The fuel filter was replaced after about 5 tanks of gas. I just fixed the EVAP issues so I am hoping the mpg goes up. I think I might have a leaky injector as well because when reading my ecm with the key on (say 5 min) I tried to start it and it ran like complete crap (felt like bad misfiring). I shut it back off waited 30 sec and fired it up and it ran as it has (slight idle shake). With the EVAP issues I was seeing a lean condition and timing retarding every time the purge valve was opened. Also my EGR solenoid was leaking causing the EGR to stay slightly open. This was also fixed. Right now my only issues are low MPG and a rough idle. Car still makes great power and no stumbling at any rpm range. Just a slight shake at idle I never remembered. Trying to explain everything that has been done the best I can. Engine bay looks like new.

 

If you still have the injector clips, I believe you can unbolt the fuel rails and lift them up to see when you pressurize the system if one leaks. Just key on and not started. Remember reading that on an old thread and maybe someone can verify this. Very easy to do and I believe its just 4 bolts.

 

Yes I was planning to do that tomorrow after work if there is no snow coming down. Also I was gonna turn the car to on (turn the fuel pump on) and use a battery to fire each one while placing the end in a 2 litter bottle. This is so I can at least see the spray pattern. Might fill the fuel rail up with techron concentrate and spray it out each on with compressed air. This should help clean out the crap. Maybe reverse flush them too.

 

DaOne, Your trace shows fueling and sensors are looking pretty good, your fans are not set to take advantage of the 160* T-Stat, but no biggie. However a problem that I do see is you are never entering Fuel Trim Cells (BLM Cells) 16, 17 or 18 . Cell 16 is used for idle (TPS=0% and speed = 0) however you are in cell 4 at that condition (beginning and end records of trace) . You also never use cell 17 and 18 for deceleration or coast down situations. I can't figure out why this is happening, in the past I have seen bad .bin loads or bad EGR disable tunes causing the problem, but nothing definite. Is you tune really stock or has it been altered with the Hypertech program you mentioned. I have a '95 A4 stock .bin if you want to try it, PM me with a valid email and I'll send it out. Do you have a copy of you active .bin, if so PM me and I can look at it for any obvious problems..

 

Bob, I reset the computer by pulling its fuse right before this log. The drive was about 40 miles. I did this due to the evap issue I was having that I had just repaired. I am not sure if that would be whats causing the issue. I have modified this computer with the Hypertech PP+ but it was supposed to put it back to stock when I removed the programming with the programmer. I do have both bins saved (supposed stock and the one with my hypertech installed.) I can email them if you like? Gonna PM you my email. Also my options on the Hypertech were the 160 deg stat for the fans, the top speed limiter, the shift firmness, and the engine tuning. The crazy part is in tunercats there are zero changes to the transmission when comparing the hypertech bin to my stock one.

Thanks for your help,
Wes

 

Well I noticed you were running at 193 (I think). With my 160 T-Stat I turn fans on low @ 185 and high at 190. Could be Hypertech uses higher fan turn on temps.
I received your PM, the 1995 stock A4 .bin is in the mail. You can reply to my email with the .bin file dumps from your PCM and I'll try to take a peek at them. I've tweaked my shift points to shift a little sooner with my 3.42 rear and yank SS3200 my RPM's are getting up there sooner and it feels better to catch the up-shifts sooner. That's a personal preference. I also added the Firebird TA performance switch mod that gives me an additional set of transmission control tables at the push of a button, fun to experiment with.

 

Bob, got your file and sent you mine. Also noticed quite a few changes. Have a few questions. I also did the performance button mod on mine.

 

Well I pulled the fuel rail today to test for a leaky injector. No leaks found but I figured I would clean them by soaking them in fuel system cleaner and a ultrasonic bath while in there. When when yanking them out one of the white plastic clips broke (ones right behind the lower o-ring). Wouldn't you know it... damn thing fell right into the injector hole on the manifold. Thankfully I was able to retrieve it with a vacuum. Next issue was calling Napa to be sure they had injector rebuild kits including the basket filter and that plastic clip (guy says he has it in his hand). I yanked all the basket filters out. Needless to say the kit was o-rings only so now I have to wait to get them. Other issue is I cant find those plastic clips anywhere. So my questions are... What is the plastic clip for? Can I just not use it? Can I run these without the filters until they get here?

Thanks,
Wes