need help with tune file. Please look

[tgeers]

Hi friends,
I have a 2002 C5 vette with a 427 stroker motor. It has a custom OS and I'm mafless. The three wires to the MAF are disconnected. Car runs great but I keep getting the imfamous P0102 code and reduced power mode. I've read the tutorials and watch the posts on this forum but I cannot solve this problem.

Please look at my tune file and see if you can find what I am missing.

Your help would be greatly appreciated.......Believe me!

Thanks
Tony

[Dtuner]

Tony
Give Jeff a call At Thunder, he is a Efi dealer, and is a vette specialist, and may be able to help you out, I'm out of the office and don't have his # with me, but you can get # his from this site. only thing I would do, is go back to square one in the wiring schematic, and completely shake it down from start to finish, good luck

Rick

[5.7ute]

Hi friends,
I have a 2002 C5 vette with a 427 stroker motor. It has a custom OS and I'm mafless. The three wires to the MAF are disconnected. Car runs great but I keep getting the imfamous P0102 code and reduced power mode. I've read the tutorials and watch the posts on this forum but I cannot solve this problem.

Please look at my tune file and see if you can find what I am missing.

Your help would be greatly appreciated.......Believe me!

Thanks
Tony

The P0102 code is necessary for the pcm to go into speed density mode. The reduced power will come from a different code. More than likely an etc or map code. P1514 If I remember right.
C6101 is the table you need to tweak if you have ETC. You need to be careful not to increase by too much as this is the table that tells the pcm if there is a throttle fault.
What I would do is first increase this table by enough to prevent reduced power mode. Then Log grams per cylinder & make a custom pid that multiplies this by 1000. Use the maximum cell value in a map that copies C6101 using the new calc pid as the data & paste into this table. Add a couple of percent & you should be good to go.

After looking at your C6101 table I am pretty certain this is the problem.
if you are etc.

[tgeers]

hey guys,
Thanks for the response. I am going to try what you said 5.7 ute, and if that doesn't work, then I'll call Jeff. The c6101 table is the one we have been tweaking. But the rest of your suggestion has not yet been tried.

Thanks again everyone that looked at this post.
Tony

[joecar]

Hi Tony,

Also, in addition to what 5.7ute said, here are some general questions/observations...

- what injectors do you have...?
- what power does your motor make...?
- are you running with boost...?
- B4001, B0101 don't look right...?
- B5913, B5914 do look strange...?
- have you been tuned using a wideband...?
- are you running auto trans...?
- what rpm has it been shifting at...?

You need to get these back in-range:
- B0203
- D0701
- D0702
- D0703
(set the out-of-range cells to max-1 and save the file)


Cheers,
Joe

[5.7ute]

Tony. You should post a log with the reduced power mode as this will give us a much better chance of helping. Make sure you log the grams/cyl pid to check if this is causing the problem.

[tgeers]

hey Guys,
I really do appreciate you looking at this. It's been a real problem in an otherwise super
car.

To answer Joecar's questions
I have an 02 vette with a 427 stroker motor with an automatic tranny. It was built by
Tony Bischoff who is currently the two time winner of the master engine builders
competition.

The injectors or 46lbs and run about 60lbs of fuel pressure
It makes 628 hp
No boost
It's tuned by a professional using EFIlive software. I believe it's called a semi-open loop
tuning. Not sure about the terminology.
I have a wideband. The lower end is tunes using the stft map and the open loop upper
end he used the wideband. Right now the upper end is way out of range and is quite fat.
The rest of the tune is very nice with -2 to -4 short term fuel trims. There's a few cells
that still need some work. But for the most part the lower range is very nice.

I am not using the MAF. The three wires have been disconnected.

As far a shifting goes, it's hard to answer that questions because it depends on whether I
have my "foot in it" or not. When I got into it tonight it downshifted from 4th to 3rd @
2400 rpm and 28% tp. My speed was 72mph. I then went to wot until I reached 5176
rpm and 113 mph. My afr was a very low 10.9. It should be about 12.56 for max
performance. So, it's hard to answer that question.

Joecar, what is your concern with the tune parameters you listed? I am not familiar with
them and don't know what they do. I will be looking at them tonight though. Can you
tell me which ones are out of range, please.
You have helped me in the past with situations and I do value your advise. Thanks.

5.7ute, the car does not go into reduced power every time I start it. But at least once or
twice a day. Just enough to keep me aggravated!! I will try and log some stuff the next
time it does it. BTW, when it does go into reduced power, it is before I start the car.


Thanks again everyone. I know you will help me find an answer to this problem.

Tony

[tgeers]

joecar,
those parameters dealing with the air pump are disabled. The cats have been removed along with the air pump. I do have a vacuum tank and the tuner says the car makes great vacuum. The car is street drivable and does not have a hugh cam. (big but still drivable).

Tony

[joecar]

Tony,

The tunetool shows you the out-of-range parameters under the Out-of-Range tab... you can click on each one to go to it.

I don't surely know, but out-of-range would make the PCM do "extra" processing when reading those tables to handle the "out-of-range" values...

For each of those tables/parameters listed under the Out-of-Range tab, change the out-of-range values (the cells showing blue ear corners) to max-1... do this for all of them, then save the file with a new filename and exit the tunetool... then re-open the new file in the tunetool and compare with the old file, and in the new file set all of them to max and save the file... and then do a cal-only flash to your PCM (observe all the precautions: good battery state on car and laptop, no power/bus disruptions, etc...).

You have to do it like that for this reason:
when the tunetool detects out-of-range cell values, it displays the max or min for those cells even tho those cells contain values x outside of min<=x<=max.

Cheers,
Joe

[joecar]

Are your shifts harsh, firm, medium, soft, or weak...?

Is your 4L60E trans built...?

[joecar]

Log the pids shown here (includes the one mentioned by 5.7ute)...

[tgeers]

Joe,
I already put everything back within their parameters. I figured if you brough it up, there must be some reason, so I went ahead and made the changes. Thanks of taking the time to explain this stuff though. The more I learn about this car, the more I'm going to enjoy it.

Am I to assume that you are thinking that some of these out of range parameters is the root of some of the codes? If so, that is very interesting. I have never heard any one ever offer up this idea before.

While I've got you involved in this, let me ask this question. Do you think there is some learning that goes on with the pcm? Some times I will make a change in the tune file and the car will not throw a code for days, then all of a sudden, it starts throwing codes every time I turn the key on. It is almost like the pcm learned to overide the changes I made.

Tony

[5.7ute]

Tony.
Comparing your tune to a stock 02 corvette tune shows that you have the P1514 ( & a few others) mil light set to no mil as well as the dtc processors set to not reported instead of A1 trip, emissions related.
This I would think is why the necessary codes are not showing in your logs to tell you where the problems lie. I know if the P0102 code doesnt report you enter some odd mode instead of speed density when the maf is failed so there may be something in this.
Any thoughts on this Joe.

Mick

[tgeers]

5.7 ute,
You are absolutely correct. A couple of years ago I made the mistake of allowing some "hack" to work on my car, and he turned off a lot of things. I think you were the one that mentioned the P1514 code. I turned that one on and immediately it came up on the dtc. Are there others that you feel are important factors here?

Tony

[5.7ute]

5.7 ute,
You are absolutely correct. A couple of years ago I made the mistake of allowing some "hack" to work on my car, and he turned off a lot of things. I think you were the one that mentioned the P1514 code. I turned that one on and immediately it came up on the dtc. Are there others that you feel are important factors here?

Tony

I would start by returning them all to stock, except of course the maf fail (P0101,P0102,P0103) & go from there. Hardware failure codes come on for a reason & should only be turned off when there is no option (deleting o2's for example when they are removed.)

[tgeers]

5.7 ute
OK that is what I'll do. Hopefully that will give me some more information to work with and share with you all.

Thanks again for your help.
Tony