Rough idle with forced induction

jwick · 08-22-2014, 07:58 AM

Mitch - Figured I would bring this thread back to life and see how things are working since it's been over a month since you made the changes to O2 sensor removal and 'cold' settings.

How's the car running? Still have any symptoms?

Ever find a fix for the hiccup or is the going theory still that the missing PCV system is causing it?

Quote:

Originally Posted by theDreamer

Check fuel & MAF readings like I mentioned in the other thread, another idea to help is if all of those with the problem could data log via Uprev the same paramters and post them. This will allow for some comparison and narrow what potential problems are causing it.

Still think it would be helpful if several of the BP guys could post log files of identical conditions (i.e. same parameters and idling conditions)

Quote:

Originally Posted by Mitco39

I think I may have found the fix today. I believe the car switches to the "cold" fuelling tables. I copied my main table into the cold (or what uprev calls cold) and it seems like its just fine now. I will have to get more seat time on it to make sure that was indeed the issue and its not just some fluke it has not came back.

Quote:

Originally Posted by Mitco39

So far so good, the lean idle has more or less stopped. But a new quirk has started which I think may be related to my changes. I been around these tuning programs long enough to realize that table names dont always mean what they suggest they should mean.

For example this car switches to that "COLD" fueling table at idle under some conditions (causing the lean spikes while idling). I would assume that that fueling table might actually not so much be a cold table as it is some sort of emissions modified table on the car. Either way changing the cold table with the main table values fixed pretty much everything. However now on hot starts it will take a second or more to crank up which also means that this car may be using this as a fueling table for starting.

My solution to this is take the cranking region of the table and return it to where it was before and see if that gives me the best of two worlds.

Either way this engine is still running strong and happy at 12-13PSI of boost.

Did the modifications to the cranking table end up fixing your hot start issues?

Quote:

Originally Posted by Mitco39

To just grab a quick log all you have to do is this (this is by memory so hopefully its a 100% correct, I dont have the cable with me currently to check it)

-Open Osiris Rom Editor
-Check for updates
-It will connect to the car and say ECU Ready after the updates are complete
-click logging and tracing
-On the right hand side of that window you will see all parameters you can select, if you happen to select to many it just wont log and you will be left scratching your head lol.
-I would like you to log the following;
-Short Term Fuel Trim Bank 1
-Short Term Fuel Trim Bank 2
-Long Term Fuel Trim Bank 1
-Long Term Fuel Trim Bank 2
-MAF flow (g/sec)
-Target AFR

Hit the red circle to record and then stop recording and save the log under file.

It will be the same ones that show up in those videos I posted last week.

The more I look at the log request list above the more I think the tuner cable provides a few more options.

Without typing them all out, pg 8 of the Cipher manual recommends the following parameters to get an eTune directly from UpRev. There are obviously some not needed (speed, coolant, speed, throttle position, etc.) but would this list provide the stuff you originally asked for?

http://uprev.com/UpdateFiles/softwar...er%20Guide.pdf

I brought this back to life because for two reasons. First, I'd really like the feedback and hopefully know if this is a good fix I should add to my next retune. Second, I kind of believe that all this still ties into my having the P2A00 code for the O2 sensor.

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