car won't idle w/o MAF (SD)
10-22-2005, 10:35 AM
#1
car won't idle w/o MAF (SD) I'm new to tuning and was going to go into SD to work on my fuel trims but the car won't even idle w/ the MAF unplugged. I reset the fuel trims before starting it and now I have to give it 5% throttle to stay alive around 1000 and any less and it dies immediately. It's like it's not even trying to stay alive on it's own. What am I doing wrong here?
10-22-2005, 11:11 AM
#2
Have you altered your VE in the 400/800/1200 volumns? Try multiplying them by 60%, 70%, and 80% (respectively) and see if it'll idle. This is just a temp fix to get it to idle, so you can then log to obtain the correct numbers. Make you sure you alter the secondary VE as well if you have one.
10-22-2005, 11:34 AM
#3
Not sure what the stock values are b/c I'm starting w/ a mail order tune but my value ranges from 15kPa to 105kPa are:
400 rpm: 33-51
800 rpm: 38-63
1200 rpm: 40-71
and the secondary table from 20kPa to 100kPa are:
400: 44-66
800: 48-69
1200: 49-71
Should the 2 tables be closer together?
Any helpful tips for this would be greatly appreciated.
400 rpm: 33-51
800 rpm: 38-63
1200 rpm: 40-71
and the secondary table from 20kPa to 100kPa are:
400: 44-66
800: 48-69
1200: 49-71
Should the 2 tables be closer together?
Any helpful tips for this would be greatly appreciated.
10-22-2005, 11:39 AM
#4
I'm pretty sure your problem is not your ve, but that your pcm hasn't figured out the maf has failed yet. Either keep it running until you get the check engine light showing that the pcm has switched to sd, or set the maf fail frequency to 0 and leave it plugged in.
10-22-2005, 12:20 PM
#6
Figured it out...did the MAF fail to zero and also found a stock VE table and did the 70/80/90% reduction in the first 3 columns of both primary and secondary tables. Car ran like crap for a couple of blocks but is running like a champ now. Thanks for the help.