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IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: Engine start very very difficult when cold. I can start the engine only using ether. Once started during warmup I can maintain only using the accelerator. To summaryse a lot of sympthomes makes me suspecting srongly the IAC valve not working properly. This valve was used on my previous engine and mecanically checked. But data in VEMS play an important role and I am now investigating on the VEMS parameters to control well this valve. I recorded log and did initial analysis. I saw that the IAC duty cycle is always 100% I saw a frequency of 200hz and PID of 255, 25, 10. I saw in other config that some are using lower frequency and different values for PID, warmup etc... How to set or get good reference parameters for a quick start of the engine and warmup available for Audi 5 cylinders ? Many thanks in advance. Laurent. -------------------------------------------------------- Hi Erikk, Thanks for your advise and I have complemented some additional info for you --------- /Erikk Is it a Bosch 3-pin IAC ? If so, 100hz seems to be the correct freq http://www.vemssupport.com/forum/index.php/topic,1900.0.html Chech that Dual Solenoid is Enabled Check wiring and that Higher DC% == More air into engine, not viceversa (forget this in case of a 2-pin IAC) -------------------------------- LoloQuattro It is a 2 pin IAC so is there something I should do ? -------------------------------- /Erikk PID values of 50/25/50 seems OK. You have to set the IAC Reference curve vs CLT to reasonable values. -------------------------------- LoloQuattro OK I will change the PID value to 50/25/50 and 100hz frequency my IAC reference curve versus CLT start at 75% for -40°c and finish at 45% for 69°C. -------------------------------- /Erikk Under "Start/Idle -> Idle Crankning, PWM" you can set DC% at crankning. 85% is probably OK at cold engine, same or lower at warm engine. -------------------------------- LoloQuattro OK, I had something very close 70% and 42% but will change ------------------------------- /Erikk Remember the fueling at cranking must be set correctly also. First set Crank VE% when warm and laborate with "Start/Idle -> Crankning Enrichment Curve" -------------------------------- LoloQuattro Erikk could you develop this point? My crancking enrichissment curve is: -20°c 300% 0°c 281% 30°c 200% 70°c 163% /Erikk ------------------------- -------------------------------- LoloQuattro What values recommanded for PWD Idle control ? Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.