Audi RS2: Long Block 2.7 liters 5cyl, Motronic VEMS, 7.5 to 1 Comp, Precision 6265, 10 bosch injectors 550cc @4bar. 034 DIS high output coils, 60-2 crank sensor.
Quattrololo:
Please find inserted additional clarification
Please start describing your setup (thematically, not chronologically)
Trigger setup
- primtrig HALL, falling or rising ?
- sectrig HALL, falling or rising ?
TDC has been set 12 teeth after the 60-2.
- (with notation primtrig/sectrig) Falling/falling is not recommended, because only 18 crankdeg clearance (which should be enough for cambelt sloppyiness, but we can be safer). Chose rising/falling (3 deg change for 21 deg clearance) or falling/rising for even better (which is a significant 360 deg = 2.5 event change, so rotate ign outputs 2 or 3 entries and also 72deg=12 teeth change in "trigger tooth+tdcdelay" to make up for other 0.5
Quattrololo: i tried falling on the primtrig and falling on the sectrig but had bad explosion.
- any specific RPM or condition for the trigger problem ?
- we should watch the sectrig position in logs (especially before the trigger-error starts), because that could reveal something important (even if this engine has no variable cams we could control) .
15/03/2012
Good morning,
Yesterday I did my first run outside, 10km on street but still have a lot of trigger error.
Both trigger camshaft and crankshaft are hall sensor.
Engine is running very very well but sometimes there are trigger errors and then misfire start :-((
There are sometimes error in trigger at idle but not many but above 2200rpm then there is a lot.
I have recorded a picture with my digital scope, trigger log and vemslog.
1) Here is a picture I have recorded. in gree the 60-2, in blue the cameshaft.
Scope synchronised on the falling camshaft signal on the left of the picture.
2) trigger log
http://www.vems.hu/files/v3.3_u003208-2012-03-14-21.29.26.triggerlog
3)vems log
yes idle is bad and engine fall often after release acceleration.
http://www.vems.hu/files/v3.3_u003208-2012.03.14-21.25.23.vemslog
Q: I am open to suggestion according to your experience.
I had a look to error trigger but could not find explanation.
Initially I thought that was maybe an expectation from vems to see the cameshaft sighal coming after a certain number of deg but according to the trigger log, it seems that there are some holes in the sequences ?? on the scope the signal look nice and sharp, maybe too low ? I forgot to measure the voltage.
A: ?
9/02/2012
audi ADU idle too high at 2000rpm, IAC badly controlled
Information relative to this topic will be moved into a folder very soon
9/02/2012
Here below are the information relative to the bad cold start when cold
MembersPage/LoloQuatro audi ADU no craking when cold, ether needed link to the log is now available
13/02/2102
still same difficulty to crank when cold, any suggestion ?
Crank when warm is fine.
OK. You need to correct your trigger setup first, because most of the time your engine is running (glitching) with trigger errors.
Only after your trigger settings are sorted can you expect anything else to work correctly. I suggest to get a known good vemscfg from similar engine/trigger type as a start.
After spark events (triggering) are sorted, cranking enrichment is way too low, you need ~ 150%-200% at zero degrees C for gasoline. Afterstart settings are also off, you need a few hundred cycles on cold, but probably only a few tens when warm. My best method to try good values is based on startup-lambda: Enable lambda heating before cranking in the wideband calibration window (Start cal., and close window), then start logging and crank the engine. If it doesn't starts for the first attempt, you may need to repeat the whole process.
There are many more suspicios values in your config but first try to start the engine. A known-good config from simmilar engine setup is strongly recommended!
13/02/2012
Once warm press the throttle and relase the idle goes back to normal, but when engine is loaded, press throttle and relaese then the idle goes too low.
What are the step to adjust the IAC PID ? I do not understand clearly the combination and effect of these parameters and the documentation is very limited on that topics.
Many thanks in advance.
Laurent.
-- First off you need a flat area of VE in the idle region, otherwise your fueling will be all over the map. Make the lower left four values much closer, right now they are off from each other by huge percentages and that will induce oscillation. Second your I factor is probably too high, but start by setting PID all to zero and making certain that your idle PWM reference table gets you close, overshooting just a bit, perhaps by a hundred RPM or so. Then when you have that commence PID tuning. If you need more I have written a whole tuning guide for AAN and have learned more since then.
20/02/2012
Dear Vasilis,
I saw on you memberpage a lot of information very good about the idle and you car.
Congratulation.
I also have an Audi RS2 5cyl and have some a lot of problem for the moment to crank the engine in a nice way and tune the idle.
It would be great detail a little bit more all the step you did to have a good cranking and idle and the effect when you change one value and the logic of reasoning to change one parameter and not an oher one.
In addition I do not understand why it takes several undred of rotation to have a start and there is no possibility to do a quick start in only few rotation ? I saw some explanation about the quick start can you develop as well is you have experience on that as well ?
Many thanks in advance.
Laurent.