Well I have been tuning for about 2 years now and feel I have been doing a pretty good job,but one part that has me totally confused is A/E.
I have had lots of bogs and lean backfires and such that I can get rid of by adding to TPS mult. but never feel my response is optimized.
I have most the A/E good and responsive in gear except when I sit and idle for a while I always get a lean back fire,even though coolant temp is not really up.
Also free revving I don't think its as good as it can get.
Ohh yeah and when I mash it in gear the W/B drops to about
10.8 at first,is that too much A/E?

Now where i get lost is there are 8 tables for A/E and they all seem to say chinese things in different order.
Any help in this department is really appreciated

 

I saw a similar behavior when i was helping to tune a friends car with a ZZ4, comp 306, stealth ram in a 91 bird with a T56.

he came to me with a basically stock chip, and it was my first time tuning a big cam so i was nervous about all the low end VE i had to take out. First pass i fixed his AE and a major bog he had. Then i started cutting VE down. I got the cruise stuff on pretty quick, but the idle was still way fat and going 108.

important note: He didn't have his VSS hooked up yet from the T56 swap, so it was stuck in BLM cell 4.

So what was happening was, sitting at idle BLMs would drop to 108. But once the cruise stuff was close this left him way lean when he first pulled out until BLMs came back up, which AE couldn't cover.


Maybe that helps, maybe it doesn't, but like i said, sounds similar to what you're describing.

 

No,Thx.
BLM's are all good.
Its one of the coolant temp tables , figured someone could break them down for me a little.

 

I use the delta TPS to get the engine to come off idle and for small to medium throttle openings.
Then the delta MAP/MAP to take care of the heavy acclerations.

And I take alot of timing out, at the lower RPM at the higher loads.

It's a blending of things to get it right.

Some engines just act lame on free revs.

 

That's exactly what I do too.

Tim

 

Thanks guys,
Ok so if I do a heavy free rev,meaning get in it quick and get a lean back fire (though intake).
Would you attack the begining of that table? or just trial and error all over it?

Also like I asked ,when I hit it heavy in gear,what should I look at on the WB? how much is too much?

Thanks alot..

 

Tune the car for the way you normally drive. Do that first. Forget the misc stuff at least for the moment.

If you have a WB you want to start adding fuel lightly to get rid of the itp in leanness, thru the delta TPS. As you slowwly tune towards more and more TPS, you see that there is a difference between what's nice around town, and what's nice at 65. As you start to get a LITTLE boggy at 65 that means you've gone a touch too far with the TPS side of things, and now you need to work on the delta LV8 AE.
Getting the AE stuff right can take a fair bit of time.

When you WOT from a stand still you MIGHT see as rich as 11:1 +-. That varies alot by car. Mine will do a high 10, then 13:1 as the turbo spools, and then lows 12s as we get moving.

 

Thanks alot grumpy, Im gonna work on.

 

Can we talk about AE for MAF? It's a good subject, and I'm looking to do better than what I have now myself. This big old throttle body is a weird responder, especially with the progressive linkage...

 

It's the same thing.
The delta TPS is the same, and the only other difference is one is delta MAP, and the other is delta LV8.

The MAF with the LV8 scaler you can really manipulate the Delta LV8, but it all gets tricky and time consuming.

With the MAFs, it just seems that you have to ramp the timing out a little faster at the low end, if your running an auto.

 

Running into a similar problem on my car.

Always had a tip in stumble, and it came and went. Now that I've FINALLY gotten my own car about where I want it, I can really narrow it down.

RPM wise, it's the worst in the 1200-2500 range.

TPS wise, it's fine above about 15% TPS. It's the worst when doing a tip in from say about 3-4% to about 12-15% throttle. It seems fine from a dead stop, UNLESS I momentarily pause at low TPS. Going from 0 TPS while cruising is another story.

It seems to be independent of MAP relatively (does it at low MAP values at low RPM, and mid MAP values at high RPM).

On my logs, O2 readings appear to go low when the stumble occurs (as one would suspect).

This is a 90 Formula (L98/auto), that is old, but mostly stock. I have checked the sensors (new O2 seems fine, but did it with old one the same way, and new TPS with good response).

I am still using TunerCat for .bin alteration, and I am slightly confused by exactly what every AE table does, since there's like 8 different tables.

Help?