OK, I am new to all this computer stuff.So bear with me if I don't have all the info. I have a 1998 A4 Z28 (lid,ported MAF,MACs,Yank 3200s stall, and Milkman tuning) that has been having some issues lately. I bought Autotap last week and here is what I found on 3 logged drives to work, never getting about 3,5000 RPM's. The numbers below constantly changed, but here is a freeze-frame of them:

Cylinder mode misfire Index level 1------19,703
Cylinder mode misfire index -------------53
Current misfires------------------------64
Misfire History--------------------------64
Cylinder 1 misfire-----------------------64
Cylinder 2 misfire-----------------------64
Cylinder 3 misfire-----------------------64
Cylinder 4 misfire-----------------------64
Cylinder 5 misfire-----------------------64
Cylinder 6 misfire-----------------------64
Cylinder 7 misfire-----------------------64
Cylinder 8 misfire-----------------------64
Timing---------------------------------- minus 49.5*
Knock retard---------------------------5.6*
TCC mode-----------------------------10
TCC Slip speed-------------------------29rpm
Trans input shaft speed----------------1.3rpm
TCC Duty cycle------------------------58.4%
Trans pressure------------------------10psi
Trans Temp---------------------------140*

My fuel trims are bouncing between -60% and -81%, both long and short terms.I also have an issue with my transmission not shifting at WOT and I think my Yank 3200 stall has something to do with it. My car surges at idle and almost acts like the converter is locking and unlocking but I'm not sure how to tell if it's locked or not with Auto-tap.I "think" those fuel numbers mean that I'm running rich but I'm not sure.... Thanks for any help guys, I'm kinda stumped!

 

I don't know much about tuning, but my car had failed the emmission test because of misfires on all cylinders. The shop said I have a bad crank sensor. We will see after today.

 

The timing value is insane and the misfire numbers
are suspiciously identical. You should see some low
(lower), random level of misfires; with a stock motor,
3000RPM converter it's still onesy-twosey for me
unless something is wrong. I don't trust that perfect,
binary value there on all 8.

I thought -25% was the fuel trim limit and beyond
that, it would just clip and set a code. Never heard
of -81% fuel trims.

I wonder if ATAP is perhaps misreading the vehicle
type and misinterpreting scale factors?

 

I have gotten an occasional negative 50 several times before. Also gotten 00's how is that different from 0?

 

Not sure about the A-tap as I'm still new to it. Would the dyno tune have anything to do with the numbers? Maybe a bad sensor or something? According to the c5 value sheet that I looked at, -99% and 99% were right on for the fuel trims. Like I said, I have use A-tap 3 times now and I am still learning it! Autotap pulls up the cars VIN so I'm not sure if it's reading it correctly or not......

 

i think short trims can go past -/+ 25% your thinking of long trims and yes @ 25% a rich or lean code will trip

 

I am going to get some new knock sensors and try those.......

 

I don’t think knock sensors will fix your problem...

Yes 98's have been known for bad knock sensors but I think you have other problems.

Can you give us some more details? Like when did this all start? Any changes made to the car right before? What did you notice 1st?

A lot of things can affect your Trans not shifting... maybe converter but it could also be related to the pcm

 

Most of the issues started when I got back from Germany after loaning my car out for 3 months. I did not have A-tap at that time. That's when I noticed the car not idling as smoothly. I changed the pushrods to some used ones and it seemed to help a little. I drove the car pretty hard at the local 1/8 mile the rest of that summer, adding MAC headers, a Yank 3200 stall, SLP MAF ends, deleted EGR, deleted AIR pump, and replaced plugs/wires. I then went to NC and had a dyno tune with Jeff Creech (milkman) and the car drove and acted a LOT better. However, I only put down 10 rwhp more than I had with just a lid and cut-out.I did NOT drag the car after the tune, then we had a shootout at a 1/4 mile track and that's when I noticed the car wouldn't shift at WOT. I bounced off the rev limiter quite a few times while trying to see if I could fix the shifting problem.So I drove the car around town but stopped racing it until I could solve the problem. I also noticed a slight "ticking" sound coming from the motor.I bought Autotap last weekend to try and find out what was EXACTLY was wrong instead of throwing parts at the car.That's when I found out about all the misfires and the knock retard. I ran some more logs and found that the misfires go up with the RPM's. I don't know what all info will help, but I have the log files saved id you need to know specific info. I am putting in new pushrods and swapping in another MAF this weekend to see if it helps the misfires. Thanks for all the input.

 

More info that will hopefully help. I threw the tranny info in there to see if any A4 gurus knew why it wouldn't shift at WOT!
2,674 RPM's:
Bank 1 O2-------315mv
Bank 2 O2-------705mv
Long term fuel bank 1-----0.8%
Long term fuel bank 2-----1.6%
Short term fuel bank 1----0%
Short term fuel bank 2----9.4%
Cam signal low---64 counts
Cam signal high---64 counts
Misfires (all 8 cyl)-64 counts
Ign Volts---------4.7 volts
Knock retard -----4.1*
MAF sensor 1-----0.049 lb/min
Rich/lean to lean/rich ratio---2.94:1
Trans temp------145*
Trans shaft input----5.9 RPM's
Trans sahft output---5.9 RPM's

5,388 RPM's:
Bank 1 O2-------110mv
Bank 2 O2-------870mv
Long term fuel bank 1-----0%
Long term fuel bank 2-----0%
Short term fuel bank 1----0%
Short term fuel bank 2----0%
Cam signal low---181 counts
Cam signal high---181 counts
Misfires (all 8 cyl)-181 counts
Ign Volts---------18.1 volts
Knock retard -----15.9*
MAF sensor 1-----0.187 lb/min
Rich/lean to lean/rich ratio---11.31:1
Shift delay-------4.53 sec
Trans temp------286*
Trans shaft input----22.6 RPM's
Trans sahft output---22.6 RPM's

 

I still think ATAP is misreading this vehicle. Too much
of the data is just not sane.

 

hmm, yeah all that info is not correct.. a 4.53 second shift delay??? That or a really messed up tune.

 

Could the custom tune be messing up the readings? Looks like I need to head to NC next weekend for another tune....

 

Those are some weird readings. Check out that trans temp!

 

also ing voltage. 4.7 and 18, Atap is definately having a communication problem. Also, if you are failing emissions due to missfires and have a cam the motor will naturally missfire more, a stall will cause the pcm to report false misfires due to the converter weighing less than stock. Its best to raise your misfire tables to a min count 2000, it should pass emissions by doing so.

 

Kevin, I have Thurs and Fri off this week or Sat and Sun evening.....give me a call. I got a couple things to try on it.


On a side note.....have you been getting gas on base? I had some really bad pinging with mine before going to Jackson. Ran the tank empty, threw in some injector cleaner and filled it back up. Runs great now. That's twice now it's ran like crap after getting gas on base.

 

Yep, I always fill up on base. I am putting in those pushrods you gave me tomorrow to see if that helps. Could I have bad ignition coils maybe? Who knows? Looks like it's a 4 hour trip to NC next weekend......

 

I don't know if this is causing all of the problems you are having but I'm telling you, the difference was night and day with the next fill up......

 

My car has been surging at idle but only in gear. I had assumed this was because of the misfires and the stall issue. I ran my AC for the first time in a while and the surging was not there.The surging ranges from 550 to about 900 RPM's. It doesn't do it in park/nuetral and it doesn't do it all the time.Maybe 90% of the time.It also doesn't do it when the AC is turned on. Could this be a vaccum issue?O2's maybe since the banks are reading so different?

 

Well,I've already swapped the pushrods and none were bent. I also ran my car empty and put in 1/2 tank of circle K gas. I then drove to Rob's house and A-tapped the car. NO issues at all. Converter locked and unlocked like normal, and only 1 to 4 misfires the entire trip. I didn't have it scanning knock retard but I will do that in a little bit.....