calibration - computer learning

[turbo84voyager]

I am having an issue with my D-cal cals and I am hoping someone can help. When I burn a cal to a chip and install it, it either runs good ( air fuel rato ) then after a little driving tends to go very rich, or it runs extremely rich right from the start. Some cals do run good. For example I have been running the same cal for some time now but I recently installed a wideband and I noted it was a little lean at WOT. I added a little fuel in the WOT fuel table and I added a very slight amount of fuel at 0" (2-3%) in the part throttle table. Otherwise the cal was the same. I swapped chips ( first time without disconnecting the battery because I have a chip extender ) and it settled out around the 14.7 area then after driving a little it dropped to 12 - 13 and stayed around there. I then turned the van off and disconencted the battery for a few seconds. When I started the van it was rich again and it appeared to get better as I drove it. I am assuming the computer is learning. Today I started the van and it was running good after a minute or two it settled in at 14.7. I parked the van but left it running for a minute and all of a sudden it dropped to 10.0 and for the remainder of the day stayed between 10.0 and 13.0. WHen driving down the interstate it started to bounce around 14.7 but as soon as I got off it was back to 10 - 13. I swapped back to my old chip and within a short time it appeared to lean out and run around 14.7. I am not sure if I have some bad chips or what can be going on here. How long does it take for the computers to adjust to new calibrations? Has anyone who uses D-cal ever experience this issue. This has been happening to me with cals I have tried in the past. Some run good wile others dont, even though the changes are extremely slight. I am not sure if this is normal for it to run very rich like this before it settles in.

Thanks,

Justin

[cordes]

What ECU are you using? Are you getting any codes? What base cal are you running? Injectors? Map?

[turbo84voyager]

89 SMEC. I am running a 2.5 g-head cal from Matt ( Moparzrule ) which I fine tuned to my van. It is a 3-bar cal, I am using a MSD 3-bar map, 40+ injectors and the cal is set up for 40+. The cal runs fine and the air fuel is fine, but when I make a small adjustment sometimes the van runs pig rich and does not seem to want to adjust to the cal. I am not sure if I got a bad chip or 2. I wrote my cal which I have been running for some time ( the same cal minus my last mod which is a hair more fuel at WOT and at 0" in part throttle) on to another chip and when I throw that one back in it seems to run fine after a little driving. All I did on the last chip was add anout 2 - 3% more fuel at part throttle only at 0" and more in boost at WOT. I assumed it should run the same as before with only added fuel in these 2 places. But it does not. Next I am going to change the oil ( dont want to take a chance of there being gas in there ) and I am going to burn the same cal to another chip and drive the van.

Any ideas?

[cordes]

If it just started doing this all the sudden with the cal change I would look at the cal again to make sure you didn't do anything to accidentally mess it up, and go on with your present plan.

My SBEC car will take a couple days to adjust to changes I make, but if this is a new issue for you after swapping many chips I would assume that this is not your problem.

[turbo84voyager]

I have been experiencing this issue for some time. It just seems like it is a lot worse now since the weather is coolder. I made the changes again yesturday to the cal which I know works. I will let you know how I make out over the next few days.

Justin

[turbo84voyager]

When you say it takes several days for your SMEC to adapt to the changes, what does it do? does it run rich like mine is?

Thanks,

Justin

[cordes]

When you say it takes several days for your SMEC to adapt to the changes, what does it do? does it run rich like mine is?

Thanks,

Justin

It's an SBEC, but it will idle high, especially with the clutch in as I come to a stop. I don't have an WBO2 in the car so I don't know what it is doing AFR wise during this time.