Cold start problem very rich condition

bataradena · Post by **bataradena** » Mon Feb 02, 2004 5:46 am

I’m having a problem in the morning when the engine is dead cold. The mixture is so rich; it’s hard to get out of the driveway. After the engine warms-up, the engine runs great. I received a reply from diy-efi.org about some table to tweak but having a problem location the correct one to tweak.

Here is the reply I received.

->There are a few tables that affect how this works.

->Choke AFR Multiplier vs. Coolant Temp
->This value multiplies the AFR to create the new AFR as the engine
->warms up. The number in here will determine how quickly the choke is ->let off of the engine.

->AFR at Startup vs. Coolant Temp
->This table has the values for the AFR at a given temp for
->startup after the engine has just started running. Combine this table
->with table above and you can get how the choke system works on the
->computer.

->These are the tables that usually affect your problem. You can also ->check crank AFR table as well.

I looked thought the “TurnerPro” tables but I don’t see “Choke AFR Multiplier vs. Coolant Temp”.
Below is a listing of cold tables I found in TurnerPro, but not the one I’m looking for.

1.) Cold start crank correction vs % rpm
2.) Cold AFR Vs VAC Kpa (added to AFR Vs temp)
3.) Time out AFR cool -> Choke (Sub from AFR)
4.) MAP filter Coef Vs Coolant

I have a 1989 K1500 383 TBI using the 7747-MINE.ECU

Can anybody who played with these tables for choke give me a better insight in what I need to do.
Thanks
Byron Taradena

480ss · Post by **480ss** » Sat Mar 13, 2004 5:24 pm

First of all make sure you have a full copy of the 7747-mine.ecu file. The copy I downloaded from here was not complete. I got a good copy from the GM_ECM site. It should have a table called O/L AFR vs Temp try adjusting that. It may do the trick.
Now if I could just figure out how to do or get an ALDL definition file for the 7747 I could try out TunerPro RT.... MAGNUS you out there?

Good luck

Post by **Mangus** » Sat Mar 13, 2004 6:22 pm

if you'd like to create one, i'd appreciate the help!

480ss · Post by **480ss** » Sun Mar 14, 2004 8:20 am

I've been trying to figure it out. There seems to be a bit of a learning curve to it. I've never done this before but I'm using the A58 data stream information, Set the payload at 20, Moved around and changed some of the BYTE information using your 7165 definition as a starting point, but 'm not sure what to do with the BIT description/information.

Thanks,

480ss · Post by **480ss** » Sun Apr 25, 2004 4:09 am

Oh well I guess the 1227747 ALDL datastream will have to wait till next winter when I have more time off, unless somone else will give it a try... (I'm back to work full time now for the summer 6 days a week 12-13 hours a day driving a semi) By the time I get home from work after another hour commute there's only time te eat dinner and go to sleep for a few hours before I have to get up at 3am and do it again.

jeepguy553 · Post by **jeepguy553** » Fri Apr 30, 2004 8:38 am

If someone figures out a 7747 datastream, please let me know. I would like to try it on my 8746 to see if it works. The one I made up is a POS and I can't figure out where I screwed it up.