idle surging help

[gokussx4]

Could someone checkout this scan log and help me figure out what I need to adjust?

Fast 102 intake and nick williams 102mm tb. xer251hr cam. ported heads 305 cfm at .6

I bet its something to do with the way the programming is adjusting for idle but not sure where I would eliminate the surge at.

[edcmat-l1]

Probably that f**ked up VE table. I'd start there.

[gokussx4]

Yea its not smooth at all right now I only adjusted the 0-2000 range to get it idling. I was then going to go for a drive and adjust the upper rpms.

The tables have been jacked for a while so I do really just need to smooth them out and go from there.

[Mike Norris]

Probably that f**ked up VE table. I'd start there.

If you don't have anything nice to say, don't say anything at all Ed

But with that said, that is one f'd up VE table for sure. And between it and commanding 12.5 AF it is going to surge like crazy.

[edcmat-l1]

If you don't have anything nice to say, don't say anything at all Ed

But with that said, that is one f'd up VE table for sure. And between it and commanding 12.5 AF it is going to surge like crazy.

[seven ends]

I would make sure to have the right idle area airflow scalar for that big TB in the tune first.

[gokussx4]

I would make sure to have the right idle area airflow scalar for that big TB in the tune first.

Thanks for that! Yea my VE table is definitely an issue and is being worked on. Any suggestions on the airflow scalar? I am unfamiliar with tuning that area. Thanks!

[gokussx4]

If you don't have anything nice to say, don't say anything at all Ed

But with that said, that is one f'd up VE table for sure. And between it and commanding 12.5 AF it is going to surge like crazy.

Thanks Mike. The commanding to 12.5 is the method that is usually done when tuning VE tables. The VE tables are in progress

[seven ends]

Thanks for that! Yea my VE table is definitely an issue and is being worked on. Any suggestions on the airflow scalar? I am unfamiliar with tuning that area. Thanks!

I think you can find the spreadsheet in different places on the site or offsite by searching. If you can't find it, PM me an email address and I will email it to you. For a 102 TB (8171 mm2) the spreadsheet copy I have lists a scalar (1% of area) of .012238. Put that number (with rounding as necessary) into your Idle> Airflow> General> ETC Area Scalar and then start tuning everything else. Good information in general on this site on this topic as well.

[gokussx4]

I think you can find the spreadsheet in different places on the site or offsite by searching. If you can't find it, PM me an email address and I will email it to you. For a 102 TB (8171 mm2) the spreadsheet copy I have lists a scalar (1% of area) of .012238. Put that number (with rounding as necessary) into your Idle> Airflow> General> ETC Area Scalar and then start tuning everything else. Good information in general on this site on this topic as well.

Thank you very much! I think this is a piece that I have overlooked.

[gokussx4]

Well the description of etc area scalar got me thinking. Please tell me if I am over thinking this. I have a drive by wire system, is that still considered etc?

[edcmat-l1]

Well the description of etc area scalar got me thinking. Please tell me if I am over thinking this. I have a drive by wire system, is that still considered etc?

You have a drive by cable system. It is an F body OS.

PS, on the 102s I use .0130 for the scalar. But no matter what you plug in there, if the fueling is off as bad as it is, you'll have bad problems.

[gokussx4]

You have a drive by cable system. It is an F body OS.

PS, on the 102s I use .0130 for the scalar. But no matter what you plug in there, if the fueling is off as bad as it is, you'll have bad problems.

Sorry that was a typo if you didn't notice. So since it is a cable system is it still considered a etc?

[edcmat-l1]

Sorry that was a typo if you didn't notice. So since it is a cable system is it still considered a etc?

I change them in the cable cars too. Some say it doesn't matter, but it does change the idle airflow.

[gokussx4]

I change them in the cable cars too. Some say it doesn't matter, but it does change the idle airflow.

Yes it made a difference. Not to mention I forgot to change my injector flow rate because I swapped for a set from a 98, oops yea i know

ok so all was smooth and my afr was looking good on the wideband on warm up, within 4% +- is pretty good for a ve tune.

when it gets to the end of my log you will see the problem. seems to happen when it gets to the 140F range.

The ve is still only set for the 0-2k rpm range and its only tuned in the cells i hit right now on warm up stage. I will be smoothing them out manually after i get this baby idling right.

Thanks so much for your help everyone!

[edcmat-l1]

1) The VE is still whacked. You're not logging your A/F right. You're logging it at a commanded 12.53.
2) The ETC scalar is off one decimal. BIG problem there.
3) Your IAC counts are too high. You need to crack the blade and zero the TPS, or crack the blade, remove the TPS and slot the holes, or drill a small hole in the blade. You need to get the IAC counts around 40 when at op temp, in park. Don't do anything else until you get this set properly.

Start with this tune. The fueling should be pretty close, if you're injector flow rate is correct. Check the fueling, and if it's pretty close, first thing you should do is get your IAC counts in line.

Attachment 27784

[gokussx4]

1) The VE is still whacked. You're not logging your A/F right. You're logging it at a commanded 12.53.
2) The ETC scalar is off one decimal. BIG problem there.
3) Your IAC counts are too high. You need to crack the blade and zero the TPS, or crack the blade, remove the TPS and slot the holes, or drill a small hole in the blade. You need to get the IAC counts around 40 when at op temp, in park. Don't do anything else until you get this set properly.

Start with this tune. The fueling should be pretty close, if you're injector flow rate is correct. Check the fueling, and if it's pretty close, first thing you should do is get your IAC counts in line.

Attachment 27784

Thanks for replying. Unfortunately your file can't be opened "index was outside the bounds of the array". I am running 2.22. What version editor do you have?

[gokussx4]

To add: While I was waiting for a reply this evening I opened up the throttle blade to .71 volts and my IAC's are down to 60 but I know that isn't 40 but typically that is acceptable.

The one thing that bothers me is even at this point when I am logging my value is at .71V for tps and my iac's are at 60 but my TPS % is at 1??

The tps % in the on position, turning from the off position, is at 0. So once it starts the it will change to 1%.

I notice this before starting this project and decided to replace the tps, just in case. So that still doesn't seem to solve that issue. Maybe my problems are all due to ve being screwed up but I wanted to bring that to light as well.

Thanks edc for your help on this.

[edcmat-l1]

You need to email [email protected] for the latest beta.

You also need to follow directions when someone gives them to you. Reset your TPS. You need to get your IAC counts a bit lower in park, beacuse they will go up in gear. Need to have enough head room for that.

Modify the TPS by slotting the screw holes so you can turn it slightly. Or do a TPS reset (may not work in your case) or drill a small hole in the blade. Any of these methods will work.

You have way more isssues with your tune than the VE table. Get the beta, and plug in the tune I posted.

[gokussx4]

You need to email [email protected] for the latest beta.

You also need to follow directions when someone gives them to you. Reset your TPS. You need to get your IAC counts a bit lower in park, beacuse they will go up in gear. Need to have enough head room for that.

Modify the TPS by slotting the screw holes so you can turn it slightly. Or do a TPS reset (may not work in your case) or drill a small hole in the blade. Any of these methods will work.

You have way more isssues with your tune than the VE table. Get the beta, and plug in the tune I posted.

I appreciate the information you are giving me but not everything you are saying makes sense. If it doesn't make sense I won't do it, period. So do me a favor and explain why you are changing something and how it applies. If you do this I will follow instructions to a T.

There really isn't any reason to get fussy about which parts I have chosen to follow.

BTW the tps % resets it self after you adjust the tb screw. You just have to turn the car from on to off several times. Mike Norris taught me this and it has been proven to be accurate for my model car.

Thanks again.