VEMS Community Forum
Technical => Ignition => Topic started by: Bambi on September 09, 2011, 06:13:21 am
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Hi All
I have a high boost (above 1.5bar) misfire on AAN with LS2 UrS4/S6 Plug and Play Coil Kit. Firmware 1.1.88.I tried upping the charge time to 4.5 ms but no difference to running 3ms. NGK BCPR 7ES Plugs gapped to 0.5mm. Eventually put in 4 Prong 1.8T plugs gapped to 0.5mm and now OK to 1.8bar, but idles with faint hickup and will not do 2 bar boost.
I read the other posts and wonder if I should ether try the parallel 500ohm resistors, but I don't know where to mount them (on the PCB directly it sounds?) or running plugs without the "P" or even without damping resistor? Can the lack of an "R" cause damage or only interference?
Thanx Leon
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My suggestion is not to use any other plugs than Bosch F5DP0R.
With those 3B engine with native single coil is capable to 2...2.5bar boost.
Additional 500Ohm resistors in parallel with existing 500Ohm are required for 1.8T coils. And just for I259 logical outputs. 1.8T coil has strong pull-down resistor inside. Because of that input current is higher than normally.
From datalog you can found is it exact cylinder what misfires or is it random behaviour. Usually 4 coils are driven by stepper chip (strong signal) and one - from I259 logical output (not so strong signal).
Gints
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with those plugs, I have misfire from 1 bar up. Funny enough, with 1.8T coils all is fine (borrowed some) - except that I don't have them, and I bought the LS2 kit as it was advertised as a higher performance option.
In the "normal" setup for the AAN in 1.1.88 is the output voltage to the coils 5V or 12V. The LS2 supplier felt that I had to change the voltage regulator to 14.5V as they want higher charge voltages than other coils. I am starting to doubt wheter these coils can perform as advertised...
If I tried the stepper route as described by Rob, will it help?
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With the motronic 55 plug though, how di I change the wireing and what settings to run for the assignments for 5 cyl AAN?
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if they are EFI LS2 coils they perform very well I use them on a 2.5 stroker ABY
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Yes they are. What plugs are you running and what boost? Whats your driver config and charge time settings?
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Depending on coil, wires and plugs and the combination of them you can get into trouble. Never played with LS2 coils but had issues with noise (USB adapter flipped out, and trigger errors). Simple remedy = resistor spark plugs.
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Out of interest why are you using NGK plugs? The stock bosch ones are used as upgrades by the s4 / rs4 bi-turbo owners!
I've had my car to 2 - 2.5 bar boost, quite a few owners on s2forum have used these kits no issues.
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OK, I bought 5 new Bosch F5DPOR plugs - friggen expensive, but worth it I know.. - but now its even worse. I puts the NGK's back and still even worse than before. Now the car wont even drive normally without misfiring all over the place. It's like every time I swap the plugs, it gets worse. I don't get it. The LS2 kit is brand new, the plugs are new, the VEMS is new. Not sure what to do now except drive it till whatever it is fails completely.
Could I have damaged something by running 5ms dwell? Or maybe with a run on non "R" plugs - both of which made no difference.
HELP! PLEEEESE ??? ???
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5ms? Sounds a bit high! Take a look on your datalogs. What is dwell when boost hits?
What is your coil charge MAP scale value???
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I set the charge time to 5ms as a test, but made no difference. I run it at 3.8ms, with mapscale 1. I tried up to 5, still no change. I'm going to borrow my mates 1.8T coils again today. Previously with those I had clean boost up to 2.5 bar with no issues on 2.5ms Maybe the LS2 kit just needs more voltage, but I don't know how to give it to it.
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I tried 1.8t coils on various vehicles and had never problems with them (from n/a to 2.5 bar). You could drive it with 1.8ms dwell time without misfire up to 2+ bar. I259 outputs with 500 ohm in paralell works just perfect. Maybe you damaged your coilpack with 5ms dwell time.
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Reading this:
http://ls1tech.com/forums/generation-iii-external-engine/1337141-dwell-time-coils.html
I think you'll be fine with 5ms dwell - all that will happen is that the coils will start to get hot - you may end up overheating the coils, but remember these things are "off" more than they're "on"
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are the I259 outputs marked on the PCB or is there a scematic I must use to identify them?
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Not marked. Here is good pictures:
http://www.vems.hu/wiki/index.php?page=MembersPage%2FGergelyLezsak%2FAssemblyThreePointFive
here is layouts and schematics:
http://www.vems.hu/wiki/index.php?page=GenBoard%2FVerThree%2FSchematic
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Are the plugs ok when you take them out? If not check injectors wiring and solder mounts especially flyback route.
Check connection IGBT cooling surface that they get cooled correctly.
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Where are you grounding the coils too?
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Are the plugs ok when you take them out? If not check injectors wiring and solder mounts especially flyback route.
Check connection IGBT cooling surface that they get cooled correctly.
IGBTs are built into LS coils. So these coils should be driven by stepper outputs or logical outputs. Means - no IGBT.
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Where are you grounding the coils too?
Good question! There is two grounds for each. right?
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I first had the ground on the tappet cover where the standard coils are grounded, but then moved th ground to the firewall - made no difference. the kit came as plug 'n play so there was only one ground - as per the standards coils.
Maybe I should use the stepper outputs - but I unsure how to setup and rewire for 5 cyl AAN. Is there a guide I could use. I read Rob's post on the subject, but I'm not sure how to do for 5 cyl AAn with the motronic 55 header on it. Has any one done something like that?
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Hi Rob
Do I do all the wiring changes for the 5 cyl AAN as per your example for the 4 cyl. i.e.
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The wires must be swapped from the Ingition pins on the EC36 plug and moved to the EC18 plug as follow
Coil 00 EC36-pin35 to Stepper A EC18-pin4
Coil 01 EC36-pin33 to Stepper B EC18-pin10
Coil 02 EC36-pin34 to Stepper C EC18-pin5
Coil 03 EC36-pin36 to Stepper D EC18-pin11
******************************************************
Must I assign a “Coil 05 EC36-pinxx to Stepper E EC18-pinXX ??? for the 5th coil.
How does the fact that I have the motronic 55 plug influence things?
For the assignments:
************************************************************
Now we change the ignition outputs Settings->Ignition Outputs from the EC36 pins to their corresponding EC18 pins.
So that the coil drivers are mapped to the pins correctly, reflecting the wiring changes made above.
Do I just assign in sequence old: i.e. 54231 to same sequence EDBCA
Or can the stepper outputs not be used for the 5 cyl AAN?
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I measured the trigger voltage on the coils, and no 3 coil has 5V, rest is 12V. I contacted the supplier of the coils and they said that that is ok as the LS2 coils are driver in the oem application by 5V. They did say however that found that the spark plug connector had been faulty on some of the kits they sold, and that arcing occurs from the HT lead to spark plug connector joint to the head, and from the plug to connector interface to the head.
I noticed that lately under 0.5bar boost I now get firfire of first one cyclinder, and then at 0.7bar a second cylinder misfires as well. They offered exchange the leads for new improved ones, or to give me credit if I return them and buy higher rated magnacore (might have mispelled) leads. Does anyone have recommendations in terms of leads?
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That is interesting.
i have had LS2 coils, probably similar to yours for the past year, running dwell quite high, as i was told by EFIexpress that they are ok running 2.5ms charge time and 20 map scale, and have never had any misfires. So if it isnt a spark plug problem, it may be a faulty cable or coil.