Does that mean my LT/ST fuel trims are out of whack? I dont have the equipment to check them anymore should I be working on that? The OBDII reader I have is the cheap one doesnt let me check it..

Ive already adjusted my fuel map on the UTEC but Im worried Im going to have to do it all over again if the temperature changes drastically again. I kept the old map and put the changed one in another slot so I can just switch back and hopefully the a/f will be corrected in the event it does happen again to save time but thats like a bandaid.

But my a/f went from 10.5-10.6 between 2,500-4,000rpms (low boost/spoolup) down to 10.0-10.2:1 when it was consistent for at least a month at the a/f I had originally tuned it at.

Could I correct this by messing with the intake air temp correction in the parameters? Suggestions about that specifically would be great to hear

-paul

UTEC
PE650s
Walbro 255lph

do you have the latest firmware (utec software)?
if so, the temperature compensation could remedy
your problem. do you have a laptop?
do you know how to datalog?

yeah, i normally use logger 1 but do one of the other ones log the temperature compensation ( so I know if its in effect or not)? I think ive got the latest UTEC download that has the option for speed density from september 06' is when i downloaded it. I tuned my whole map from scratch with PE650s so you can be specific with me, I just never messed with the temp. compensation before

With the temp. compensation whats the norm there? The values are (-10)-10 right? So if I put a value of 1 in the temp. compensation section at any of the temperatures its going to be like adding 1 whole percentage to my fuel map everywhere once it crosses that temperatures?

So in my case since I already took out fuel from the map since it got warmer, so I should be looking to add fuel back when my IAT gets below a certain temp.?

paul if you knew your colder weather map was good and stable (ie fine all winter), use that as your basis.

then, in the currently warmer temps, pull fuel using the temp compensations.

well I switched to speed density, with the stock MAF in its current location in my perrin shortram. speed density wasnt so hard to tune for WOT(in fact the values are very uniform compared to my old maf based map. but getting the transition right in the lower columns is tuff. and also if i start the car and let it idle for a while as the ECU lowers the rpms and closes the TGVs my a/f jumps a bit and the idle goes crazy for a minute or so. I still used logger 1 for most of my tuning, i cant figure out how im supposed to use the special logger for SD to help me tune. Ive got the injector size set to 650cc and the deadtime set to 1450.

What are the VE percentages telling me and how do I use that to tune?

in anycase its been alot of fun to re-tune the car in speed density but im not sure if i can keep it like this without moving my MAF sensor since the air temp reading im sure are skewed. But the car runs well.. but i still feel the need to constantly check my wideband to make sure the a/fs are the same as the last night:lol:

I heard some knock at 4,500 rpms and my UTEC didnt log anything during the speed density tuning, kinda irked me. I had lowered my sensitivity settings a bit because of false knock readings but now i realized i lowered it too much.. at least around that rpm i did because my motor is alittle noisy

speed density has been working fantastic, the a/f are solid up top and the values in most of the columns are within .5 of each other i hardly had to do any work. Im trying to get the a/f to smoothly transition at part throttle still as it jumps from stoich to around 13.1 once it gets into the 10% column so if I slowly get off the gas it jump back to 14.7 way too quickly and its not smooth at all. unless i run into any issues with keeping my MAF sensor in stock location im going to stay with SD