Car is my friends '86 928 S with 4.7litre V8, Strosek body kit and ultra-wide Folger 18inch wheels. Engine produces 310hp stock.
This is the beast:
It has LH-Jetronic from the factory. LH is fuel only, so spark is distributed by two(!) 4cylinder dizzys!
That's going to change because I threw old engine compartment wiring off and ignition is going to utilize VW COP's.
Car has 100-1 tooth wheel on the flywheel with VR sensor.
What redline RPM are you aiming ?'
A: No more than 7000rpm
14.09.2006
Hooked a customers VEMS box to the VR sensor to get trigger config ok until cars box arrives. After some tweaking I got steady rpm signal without trigger errors.
So, one (probably the biggest) obstacle is defeated!
21.09.06
Got the new connectors for the COPs (VAG part number 036 905 715 A) and trying to figure out the pinout for them. It seems to be the same as the ones at the COP page here (pin1- +12V supply, pin2- Ground, pin3- +5V signal and pin4- Ground), but can anyone confirm this?
I measured the resistance between pins.
it's like that: Between pin 1 and 4 = 390 ohms, between pin 3 and both 1 and 4 40kOhm and betweens pins 3 and 2 16kOhms.
26.09.06
Got the wiring done and since I have two of the 8 COPs needed, i thought I'd try to get a spark on the plug. Ok, got everything hooked up correctly and I set dwell to 3ms, cranked and.....Nothing!
Disconnected the coil and measured (how? what equipment ? what settings ?) the output of Genboard while cranking, it was something like 1.2-1.3 volts for a second and then dropped to 0.08-0.1 volts.
If you measure with a DVM in DC mode, that measures mean voltage. Eg. 5V, 20% of the time (80% off) measures 1V
Answer: Yes, I measured DC voltage and it triggered nicely 1 V, so it's all ok then? I set outputs to sequential and it gave 1 v reading after whole firing cycle.
But, what I don't get is spark!
- Check InputTrigger/TriggerLog ... maybe no need if no wheel errors and RPM steady
- MegaTune log is often useful
- config and tables for this car: MembersPage/PeepPaadam/Config_Tables
- config looks like wasted spark setup. I'd start the car with wasted spark coilpack, and only move to COP later.
- check if the right outputs are selected
- make a separate page for ignition wiring. Sounds like you try to drive 2 COPs with 1 logiclevel signal ? This might work, unless the COP input impedance is too low (primary suspect?).
- make sure there is fuse protection for each ignition transformer (3A per transformer; if it's only possible to fuse them paired, than 5A; use 7.5A if fuse powers 4 channels; use 10A if fuse powers 8 channels, but use more fuses if possible, that is always possible with COPs).
- use mdn03 (mdn02, mdn01, mdn00) to fire small spark (make some sparkgap - not necesserily from sparkplug - outside the engine so you can see; make sure the total gap is sufficient, eg. end of stripped wire 1mm from block ). Try to drive just one COP from an ign-channel, even if your original plans were to drive 2 COPs from 1 channel
MembersPage/PeepPaadam/PorscheIgnition
28.09.06
It turned out that the owner gave me wrong pinouts for the COPs and when I found out about it and fixed it by swapping two pins, I got good spark immediatley at the plug!
I'm going to connect fuel pump tomorrow and attemt to start the car.
3.10.06
Started the car today after i connected the fuel pump.
It ran ok, except for lumping a bit below 2000rpm. What could be the cause of that?
And one more thing. I got trigger errors in MegaTune near 5500-6000rpm and misfires, resulting loud backfiring through the exaust.
Datalogg is here:http://www.hot.ee/raceboy911/928.xls
Any ideas?