Predator

Fellas, I haven't been able to find much information about this topic doing a search, but my problem is that my idle is great except when I shift into reverse (M6). It dips to around 400 or 500 rpms and the car wants to stall as I back up. I have to rev the engine to keep from stalling. My normal idle is almost perfect. I've made changes to the base running airlow (+2), bumped up the timing in the idle regions, increased target idle speed, and adjusted VE in the 400-1200 region.

Is there a table or magic bullet in the HP Tuners software that would address idle only when putting the car in reverse? Otherwise, my car is idling perfectly. Thanks.

2TR

Post copy of current tune with a log of issue occurring.

Predator

Oops, I never logged the car in reverse, plus I scan using EASE and edit with HP Tuners. All I have at the moment is my tune (attached).

I haven't scanned the car recently. I do plan on logging again since I've had the car in storage the past two years. I guess I was looking for possible tables/ settings I should look at, but I know, I should probably have a scan before I ask my question. Anyway, thanks for the reply.

DMM

I have the exact same problem...I back down my driveway in N and the idle varies from 500-1000 pretty bad. Also happens from time to time when in stop and go beltway traffic for a long while, but from 800-1000....but rare occurrence.

I have done the same things you have tried to no avail. Mine happened when it was stock also, just not as bad. I don't know if this is something that can be adjusted.

wait4me

iTrader: (10)

Is the problem only when cold or also when hot?

If cold, it may be your Cat light off tables. To bring in the temps on them quicker, the ecm will add timing really high during that time to bring up temps.

Also have you tried to MANUALLY OPEN YOUR THROTTLE BLADE with the set screw up a bit?

That will fix alot of that.

Predator

Thanks wait4me, it's mostly a problem when the car is cold. I haven't messed with the throttle blade, just increased the idle rpms. I'm not sure what the Cat light off tables are. I'll look for them. Thanks.

wait4me

iTrader: (10)

It could be a lean or overly rich condition as well if more to the cold side of engine running. Try also allowing the ECM to go into closed loop faster. That or also just monitor ltrims and strims while the engine is in closed loop. Try to get them close to 0 as possible.

On those older ecms, i give the os permission to adjust 50% in each direction as a safety, then i also shut off ltrims, and just allow the ecm to use the much faster Strims only. Then i target the Fuel trim cells to be more accurate in the areas i actually use instead of the stock grid...

Predator

Thanks again wait4me, I need to do some logging and incorporate your ideas. Much appreciated.

2TR

Im confused. Why would you update the stock tune to allow for a 50% fuel discrepancy then allowing correction using the temporary memory of the STFT's which resets everytime you turn off the vehicle? Isn't stock setting of 25% fuel discrepancy enough of an issue to tell you that your tune needs fixing by adusting your VE/MAF table instead of relying on a temporary fix of STFT's?

wait4me

iTrader: (10)

It will still throw a lean code at the 25%, however, it will save you if something ever comes up and it needs to fix itself.

Everyone knows that you want as close to 0 as possible. I just add one more Safety feature to the mix of things..

You never know when a fuel pump may start to fail, or a mass air meter may start having issues, or some other issue. If the computer knows what it wants, why not allow it to do so???

Once you see you have a issue, you can fix it. But if something happens and fuel pressure drops, or you have something onthe maf that makes false readings, and the fuel is at a max +25 trims, and you are on a trip out in the middle of the no where, and now you are still 10% lean, Would it not be a good thing for the computer to have the power to bring you back in line still temporarily????

It still shows codes.




As for Using Strim vs ltrims. Read up on our Custom Os for boosted applications. This is also used in this to allow for very accurate tunes as people with EFILive have been doing this for years with VERY nice results.

2TR

Yet another TYPICAL tuner error. Your new injectors where not tuned correctly. The shop (name?) didn't use the correct data. They took the stock tune, added +4lb/hr to the stock value of 26lb/hr and moved on. FAIL! That data would be good if the replacement injectors where rated 30lb/hr @ 58psi (GM fuel rail pressure) but unfortunately those injectors are rated at a much lower fuel rail pressure. Since injector data is the basis for the entire tune the tuner needs to start over...period. Yet another TYPICAL tuner error followed by a baked final results tune. Your new injectors where not tuned correctly. The shop (name?) didn't use the correct data. They took the stock tune, added +4lb/hr to the stock value of 26lb/hr and moved on. FAIL! Since injector data is the basis for the entire tune the tuner needs to start over...period.

Predator

I screwed up. I recently (about two weeks ago) changed my injector flow rate data using the data contained in the HPTuner experiments web site in the "Idle Tuning" blog for SVO 30s:

http://redhardsupra.blogspot.com/200...1_archive.html

I had the correct data in that table years ago but changed it. I never threw an O2 code so I must still be in the + or -25 LTFT range. I'll change it back and I should be okay.

I haven't been tuning for a few years so I forget practically everything I had learned years ago. I'm essentially starting over again. I just took my car out of storage and I've been trying to get my idle to run better, and I have except for the going into reverse dip.

Thanks for the heads up!

Predator

2TR, just to add, before I stored my car my LTFTs were slightly negative with the original injector data. After changing the IFR rate I'm sure I screwed that all up. Since I haven't done any other mods to my car when I had my LTFTs dialed-in, I should be okay if I just restore my previous data. I still need to scan my car though. Again, thanks for picking up on that.

Predator

Here's the original Flow Rate vs. KPA that I had prior to recently changing it using the data from the HPTuning experiments page. I don't know what I was thinking since I already had it setup to give me slightly negative fuel trims.

2TR

Damn sorry for the call out man! Lol

Pro tuners around the country are still making this mistake so don't feel bad.

Your attached 2nd tune has Flow rate vs. KPA values of

32.24 32.49 32.68 32.86 32.99 33.36 33.42 33.73 33.79 34.04 34.23 34.35 34.60 34.78 34.91 35.16 35.34

This isn't correct either...

2TR

Though I have EXACT Ford SVO 30lb injectors data for all of the following tables (see below)

Flow Rate vs. KPA
Short Pulse Limit
Short Plus Adder
Minimum Pulsewidth
Injector Offset vs. Volts vs. Vacuum

I did have to pay $250 to obtain such copyrighted data from the www.SummitRacing.com Greg Banish EFI Tuning Beginner DVD.

__________________________________________________ ___________

On the other hand using the FREE option from Hp Tuners (old way of doing things) which gives you an estimated fuel correction see the attached below. Again this is ONLY (1) of several tables that should be adjusted to begin with correct fuel data.

Xcel is an attachement option on Ls1tech.com so I had to attach a screen shot of the data the FREE option provided. Enjoy!

Predator

Thanks 2TR, I never graduated to SD tuning, and I have a stock MAF, so I leave the MAF table stock and adjust LTFTs by altering the Flow Rate vs. KPA table. I know I need to further my tuning education.

It seems you're saying to insert absolute values for the injectors and adjust the fuel trims using a different method, the VE tables I assume. At that point I'm in over my head, at the moment. I might have to wait until next spring to really buckle down and advance my tuning knowledge to the state-of-the-art, but your "call out" has helped me in the meantime with my antiquated tuning method .

Merry Christmas dude!

2TR

Yes you NEVER tune other values by skewing your injector data. That's a 90's tuning solution. Wanna learn more? Read! Wash, Rinse, Repeat...

http://ls1tuningguide.com/index.php

http://ls1tuningguide.com/tuningmanu...ons%20rev3.pdf

edcmat-l1

iTrader: (10)

Look, don't come in here after buying a book and a CD and exclaim to have the answers for everyone's problems. Injector data is not the holy grail of tuning. Remember, the data supplied by Banish is his calculations, not those of the injector manufacturer. And while I have great respect for Greg, his knowledge, and abilities, I take issue with you and the rest of the injector ***** thinking that it's the root cause of everyone's tuning issues.

The SVO 30s are a no brainer to tune. You can have a perfectly working tune even if you left the IFR stock. All that's going to happen is your MAF and VE table are going to be off. The 30s are small enough that the low speed (low pulse width) behavior of them is so close to stock the offset doesn't matter.

Much larger injectors are a different story. If we were talking about 60s, or 80s, that would be different. But to mislead the OP and anyone else reading this that for some all encompassing reason the tune cannot possibly work without the set-in-stone injector data handed down from the tuning Gods, well, that's just wrong.

As for scaling injectors being 90s technology. It's still done today. What do you do when you drop 80s in an E40 car? Yep, ya gotta scale em. They work pretty good too. Why do you have to scale them? Hard coded 63.5 lb. per hr.

What do you do in the computers that don't have the fancy offset tables, etc, that the GMs do? Yep, ya just plug in the numbers for the data you DO have, and ya make it work.

What do ya do in a boost ETC car, when you can't keep it from going into REP, even with a maxed P1514 table? Yep, ya scale the VE and IFR and then all is good and peaceful in the world again.

Merry Christmas to everyone.

Flame on............

edcmat-l1

iTrader: (10)

Now to address the OPs actual problem. First thing, after you get at least your IFR correct, is to get your fueling @ idle pretty close, then adjust your throttle blade until your IAC counts are in the 40-60 range when the engine is fully warmed up. This is going to help alot. You need to adjust the blade, then do a TPS relearn. This procedure will probably take several times to get right. After you get the TPS/throttle blade/IAC count when warm right, you'll need to then do a cold start and plot the idle airflow histogram, and copy it into the tune. you'll need to do this twice, once in park, and once in gear. It's time consuming, and it will take several tries, but it will help a bunch in how it all works over a wide temp range.