SuprJames

Hey everyone. I've got an 82' Stingray with a Lingenfelter/Accel TPI setup. I'm running sequential injection with Accel Calmap Gen. 7 software. I've got the car running pretty well, but right now I'm using pretty much guesswork for the values in the A:F map, cylinder head fuel coefficients,and ignition base advance maps. In a little over my head (over many people's heads I've discovered looking for help).

I don't know if any of you have aftermarket programs, but I know all of you are running sequential fuel injection. I was wondering if anyone knows where I can find info on fuel mapping. Any books or websites. I'm pretty sure I'm running really rich right now. The mechanic Accel suggested is mostly a Ford guy and sounds like he just plays with it till it works. It would be nice to have some equations and guidelines for figuring out all the maps. So,any help would be appreciated. :confused:

Avanti

Running an ACCEL system, why cannot they help you? I've always started with the distributor (seldom the manufacturer though) of the system when dealing with aftermarket FI's. All the best. :yesnod:

Oops, I forgot, I'll get you the contact info for a guy in IL (as I recall) named Rance who sells and services ACCEL system. It will be tomorrow and if I can find it, I'll IM you, if it's finally working again. Sorry, I forgot, I've been dealing with Compomotive and others of late.


[Modified by Avanti, 5:19 PM 1/8/2003]

SuperFast80

I have no help here but just wanted to chime in and say that your car sounds waaaaaay cool. :yesnod: :thumbs:

SuprJames

Thanks SuperFast80!! Hopefully it will be when it's straightened out. :cheers:

Avanti, just IM'd you and didn't get an answer. I've been dealing with Mike at Accel DFI, but there's only so much time these guys can spend on the phone with us. Was hoping to get a book or a web site that had some good explanations about what affects what while I'm making changes. The distributor's, or Accel's EMICs, are alright, but some of them are just BS. The EMIC I've been dealing with is good, but these guys don't really have time to sit down and explain what every little thing does. I installed the system on the block, set up the software, ran the wires, and have done everything, minus some tranny work and some exhaust, myself. I'd like to see it the rest of the way through myself also. :D

If anyone was confused about the sequential injection comment it's because this was orignially posted in the C5 forum and someone moved it. :nono: Sorry bout that. :D

zwede

I'm running EFI on my '71, and set up all the programming myself. It's the Holley system rather than the Accell, but there are alot of similarities. I'll be glad to offer any advice I can.

You say you think it is rich. I take it you are running a closed loop system? If so, record a few datalogs while driving around and study them. They will tell you alot. Look at how the O2 compensator moves while driving. If it is constantly trying to remove fuel, your base map is rich.

My procedure for dialing in the base map was to drive at steady speeds and change the base map until the O2 compensation was 0 to -5%. I then did the same for slight loads (acceleration). Once I had about 10-15 points mapped this way I looked at the map in graphical 3D mode and moved the other points so they were smooth transitions in relation to the points I had mapped.

Once the fuel map is properly mapped, you can move on to the spark map, and then the rest (idle, throttle follower, acceleration enrichment and temp modifiers). The key is a correct fuel map, though. Before you have that one right, you can't tune any of the other properties.

Also, unless you have a wideband O2, you can't map the WOT fuel curve. You will have to take it to a dyno for that.

SuprJames

Awsome advice Zwede! I'll do that this weekend when some friends are off so I can concentrate on the computer. I am running closed loop exhaust.

This is only my second engine replacement and my first direct injection car so this is all new to me. Now I know who to e-mail when I have problems!! :cheers:

zwede

No problem. This forum: http://www.chevytalk.org/threads/pos...t=&Board=UBB12 is excellent for all things EFI related. Just looking through the archives there will give you many threads regarding tuning of the accell system. Also, Craig from accell is active on the board.

SuprJames

That's a cool site. Glad you pointed me to it. I'll work on those tables this weekend and load that thread up with questions soon afterward. :D