98TAauto

iTrader: (2)

My car seems to act a little weird on start up now. Sometimes it will surge and stall while other times it fires up perfect. Everynow and then while it warming up i can hear a little surge, maybe like 50-100 rpms. But again sometimes its there, and sometimes it isnt..

I played with my MAF table to get my Ltrims in wack to around -+5 bascially mult the table by 120% almost

will this effect idling any??

IAC's are weird also.. i logged one time at 200degrees and they were 30-40, then the next log they were 18-20?? WTF

usually they are around 40 though.. throttle bod has been drilled also

Ragtop 99

iTrader: (7)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> My car seems to act a little weird on start up now. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">They say that cars begin to take on the personality of their owners... <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Do you have any big drops in your rpm verus temp table? Does the surge occur at the temp where the idle goes from open loop to closed? Monitor your LTRIMs by temp and see if you go from rich to lean at any point. You might also try adding a couple degrees of timing and seeing if that helps.

It's about time for you stop messing with stuff and run the car. <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

98TAauto

iTrader: (2)

joel, where would I add the timing at??
I know where to go, but what rpm and where at down the scale?

TooManyIDs

I scaled my MAF table by 113%, with no impact to my idle.

<small>[ September 19, 2002, 09:48 PM: Message edited by: TooManyIDs ]</small>

Ben99Z28

I'd noticed the exact same thing, the MAF was mult. 119%, Ltrims looks good on atap, average -1 to +1, O2 looks good too, but the car just doesn't seems right(problems like you'd mentioned), so I'd tried different different settings~~>added from 1 to 3 degree timing at around 800~1600rpm on Base Spark (both park and in gear)...didn't do squad, infact...my car ran like crap and felt like I'd lost mucho power <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> so I went back to the previous setting, I haven't try to retard timing but as far as I'm concern my car does NOT like more timing down low <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
IAC had been jumping up and down from 40 to 0..depends on its mood LOL I had already flashed the PCM no less than 10 times with different settings in the last 7K miles, as far as I'm concern....don't mess with the timing, and the more I'd alter the MAF table the weirder my car react.

BudmanY2KTA

I used A-tap to monitor my Maf Frequncey at idle and adjusted the Maf table there.That and adding more timing at idle helped mine,but I did not have problems with my IAC changing.Maybe try an idle relearn or look for a vacuum leak.

98TAauto

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ben99Z28:
<strong>I'd noticed the exact same thing, the MAF was mult. 119%, Ltrims looks good on atap, average -1 to +1, O2 looks good too, but the car just doesn't seems right(problems like you'd mentioned), so I'd tried different different settings~~>added from 1 to 3 degree timing at around 800~1600rpm on Base Spark (both park and in gear)...didn't do squad, infact...my car ran like crap and felt like I'd lost mucho power <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> so I went back to the previous setting, I haven't try to retard timing but as far as I'm concern my car does NOT like more timing down low <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
IAC had been jumping up and down from 40 to 0..depends on its mood LOL I had already flashed the PCM no less than 10 times with different settings in the last 7K miles, as far as I'm concern....don't mess with the timing, and the more I'd alter the MAF table the weirder my car react.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">well im glad im not the only one.. maybe mult the MAF by over 119 or so has some effect on the car in the lower rpms. I guess i can always set the MAF back to stock and see

Vettepartz

I have noticed that by multiplying the MAF table by a constant pertentage, the lower end is always much richer than the mid or higher ends. I believe the table does not effect the fuel ratio in a straight linear ratio.

Ragtop 99

iTrader: (7)

For idle issues, I would not mess with the timing table above 1200. The 800 rpm table is the main one since your idle is around 850 - 900.

98TAauto

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Vettepartz:
<strong>I have noticed that by multiplying the MAF table by a constant pertentage, the lower end is always much richer than the mid or higher ends. I believe the table does not effect the fuel ratio in a straight linear ratio.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">ok does this make sense?? wouldnt it be better to leave the idle a little leaner on the MAF table?? and just richen from say 1500rpms up maybe?

if so how would you go about this?? Im not sure how to translate the MAF table values to rpms and etc

for exmaple would there be a certain cell group i could leave at say +5 and just get the rest to 0 to -3

Vettepartz

Here's what I do:
I run a scan showing rpm, fuel cell, both banks of ltft, and raw MAF input. IN MY Case (a 1999 C5) I use only trim cells 1-16. Look at the LTFT's for the different values of the MAF measured in hz. If positive, you are lean there and need to adjust at that approximate frequency in the MAF table. Go opposite for rich values. Try for all slightly nagative values, good luck.