Just a quick question, when hot what revs are folsk 1.8ts running Qpeng idling at? as mines ticking over at between 1000 and 1100 when hot (cold its around the 900 mark) what are other folks idling at? (I have no over heating issues though as the cars got a new vr6 rad on it! its HUGE and even being stood in traffic the temp in the bottom hose is only 40deg top and as soon as you start moving it rapidly drops to bellow 7 - 8 deg (the gauge stops working then and says EEE as its too cold ) im just curious as I prefer it to idle a smidge lower) cheers Karl.
Thats way too cold. If the temp isn't getting up to normal operating range (70-95 deg) the ecu will never get out of warmup mode & will never idle correctly. It sounds like you don't have a thermostat fitted. get that sorted first.
the top hose is hot, running at just bellow the middle on the dash gauge, I also have a temp gauge in the bottom hose for peace of mind.
bottom hose should stay stone cold till the gauge gets to half way, then warm up. normal operating temp for just about every VAG engine is around 90 degrees, ish or half way on the temp gauge. if it goes cold when driving its your stat is stuck open or missing most likely. size of rad makes no difference to running temps, as coolant flow should be blocked off when coolant temp goes below 87
I will double check, but im pretty sure its just the fact that the stat shuts as the rads very efficent, the in car heater gets red hot, and the top hose is hot,
any other ideas on this? thinking about it I am sure the car has a stat, Mark wouldnt build it with out one, plus like I say the rad is a raddo VR6 one so its HUGE but it does warm up quite quick and will happly sit all day long at just bellow the middle of the temp gauge. (I have only driven the car in cold weather so far back in november when it was about 6deg out side, so I would say summer it should run a smidge warmer)
might have a cooler opening stat in it, some people like to fit these. if the bottom rad hose stays cold for a while then gets warm, you know there is deffo a stat in there. if it gets warm almost straight away, you know there isnt! keep a hand on the lower hose and watch your temp gauge(s), when it gets warm look at what the temp is, then you know what degree stat you have roughly
MBE 992, as used in the QEng kit, does not control the stepper motor in the J338 throttle module ( if this throttle system is fitted). Most likely the throttle stop is mechanically set a bit high for cold start and warmup idle stability. When everything expands, when fully warm, you will experience a higher idle. This is not something I would worry about unless you tweak the base idle stop a bit lower when hot. Corrado VR6 rad is a big old thing, more like over kill on these motors. This is why you run a bit cooler over an 8v or 16v/1.6 job.
cheers for that, mine has a cable throttle so I thought it would be like on my mk1 where all you did was adjust the stop when warm to lower it a smidge but the pay off is it can be pain to start from cold. I will drop it a tiny amount and see if I can find a happy medium between lowered hot idle and being able to idle when cold yeah the rad is HUGE but should be ideal for the summer and track days to make sure everything stays happy! it just means fitting an external oil coolers a pain but then again the oil so far hasnt got above 91deg! so it would appear that the water cooler s foing it job well for a change.
do you know the pin out and function pins of the 8v throttle body on the mk3 gti 8v per chance? AGG engine i think..
cool. any chance you could send me the info to bill@badger5.co.uk i will be adding a dta to georges e45 8v mk3 in the new year and would like to retain the throttle bodies idle control if possible many thanks if you can do this cheers bill
update - I had a look at this the other day and it would appear that the throlle body doesnt have an externally adjustable stop..Ill get the part number of the throttle body at the weekend when I am back in the garage. it looked like the one found on the girlfriends arosa sport, with a spindle that goes horizontal, and not like the mk3 one I ran on the charged engine that has a verticle spindle, and had a proper metal adjustable stop
this is the throttle fitted does anyone know if there is anyway of adjusting these? as it would be nice to lower the hot revs a smidge, even if its just down to 1000rpm
I used an AGU throttle on mine & drilled and tapped a lug on the throttle body, screwed in a bolt and now have an adjustable idle. Magic!
hmm I like that Idea, im yet to take my inlet hose off but thinking about it mine must be sat fully closed, so short of playing with the fuel mix in the ecu I wont be able to lower it....I was having a blonde moment
haha!! update on this as its been bugging me, spoke to the chaps at Q peng again and they have told me there is no provision for a ecu idle controlled valve, BUT they said look for an air leak on the manifold, and if thats all fine then under the black cover on the throttle is a adjustable stop, so I can wind the idle down when warm on there.
What i did for hot idle, Was to reduce the spark angle down when over a set temperature. Doing a boost leak check can help too. I had many a leak.
I have now fixed this. I sprayed lots of WD all around the manifold and ajoing pipes while wiggling them etc and it made sod all happen! so I thought it must be a stop issue... Took the back cover off the throttle and was faced with the auto choke stepper motor, and the gearing system for it, with the throttle sat in a "default" position, if I rotated one cog one way it activated the "choke" and wound open the throttle.... or you could just open the throttle normally which left the choke alone. like wise you could actually shut the throttle completely, which made the engine run very quiet as there was no deep drone from the induction cone... but oddly the engine kept running! the problem turned out to be one of the vac lines from the manifold to the servo.. theres 3 1way valves fitted with there being a main vac line before and after the 1st of these valves... it turned out that the second take off pipe had perished on the underside and when sat resting normally it was only allowing a tiny bit of air in but due to it split under side and how it was sitting it wouldnt suck up the WD! once removed it turned out it had split nearly 1/2 round to some degree! so a quick chop and then back together, things seem better now, with hot idle being about 1000rpm. so I will see bhow things go and if the fuel economy improves along with the power (as I am think this would also be a boost leak when the turbos running... so in theory I should now be a smidge quicker..maybe) As for reducing the idle some more I may look into it depening how it goes, I dont have the software on the laptop yet to play but hopefully will soon as I think I have now fixed the CAN box as 2 connector pins were broke by the last owner. I dont think there are nay boost leaks as all the pipes were off not too long ago and the inetrcooler was cleaned out with lots of brake cleaner which didnt find any holes... so fingers crossed.
