Help With Engine/tune And Just Plain Dramas

[JET-25L]

I purchased an lt16 microtech a few weeks ago and put it in last night. Got a mate that knows his stuff in regards to tuning them and did a road tune for a few hours and got it going pretty hard on 15psi with only about 10 degrees timing. Drove it around pretty hard doing this for about 3 hours and couldn't fault it. Got the afr's all perfect and car drove really well in all areas idle/cruise/wot. After the last bit of wot tuning i cruised on the highway at bout 80k for the 10 min trip home and then all of a sudden it started running on 4 cylinders. Pulled over couldn't find anything wrong with the wiring on the computer etc and was a bit confused. Put the standard computer back in and was no different so was relieved it wasn't wiring to the computer. Drove the last 2kms home at about 30kph Got it home and plugs 3 and 4 were still wet. The others weren't too bad. Then i looked at the tops of the coilpacks on 3 and 4 and they were a bit melted and no longer shoot spark if i pull them off when car is running. So obviously the ignitors in them have blown up or something but i'm not sure why??

I have since put some old stock coilpacks in 3 and 4 and car runs on 6 cylinders again fine. Drove a bit tonight with standard ecu and no dramas. I have the coilpack cover on all the time and it was a relatively cool night when the coilpacks blew by the way. The dwell cycle on the computer is 2.5ms so not like the coilpacks are charging for too long as that's what most imports run and it came with that on the base tune.

If plugs 3 and 4 fouled for some reason and i drove for another 2kms to get the car home could that cook the coilpacks? I wouldn't think so coz shouldn't the power just blast through it or earth back out?

I really have no idea why they blew up as surely driving fairly hard for 3 hours would have been harder on them than highway cruising.. Just want to try and sus it before i purchase a new set of splitfires and prevent it possibly happening again when i put the computer back in.

Steve

[JET-25L]

I have a plug and play that's how i can change back to the standard computer. Yes i have series 2 coils and internal ignitors the splitfire coilpack number is dis005 had these in the car for about 50 000kms and never had a problem with them till the other night.

I thought 2.5ms would have been perfect for them?? Wouldn't anything under 3ms be okay? I'm not sure what it could be because the only setting in the computer that really has to do with them power/heat wise is the dwell and the coils get their power directly from the computer.

[James_03]

What I have seen some people do is run the X6 ignitor box combined with S2 coils. That will give you melted coils. I noticed you have a S2, so you should be running the inbuilt ignitor's on the S2 splitfires.

How has it been wired? did you get it with a plug & play conversion loom, or has it been wired into the stock loom?

Let me know what that model number is off the coils, and if your running a plug & play loom. Dwell cycle of 2.5 shouldn't kill them, there just being belted with excessive current I believe.

Edited August 4, 2009 by James_03

[payback21]

I recently had a problem with a intermitant miss happing for about 2-3 min while driving and then it would disappear. After changing coilpacks, checking pulgs, wiring etc it turned out to be the ignitor. I changed it and my problem was solved.

As you may already know that the s1 rb26 have a external ignitor that can be changed but with yours being a s2 33, changing the coilpacks is your answer.

The only reason why i could see yours failing would be that they are overheating while your giving it a hard time. I would leave the center rocker cover out to disperse the heat better.

I picked up a set of yellow jacket coilpacks from Paul @ Performance Wise. $370/set

http://www.performance-wise.com/

Yellow jackets are half the price of splitfires and i recommended them as it did make my car run much smoother and rev better.

Hope you find your answer!

[mad082]

i had a mate who had issues with his microtech, except it melted the ignition driver on the board and then when it got repaired they put a different board in and didn't tell him.

[rob82]

Hmm interesting that its 3 and 4 as in a wasteged spark setup these will be the paried coils. From what I've seen even on the supposed 6 igntion outputs is that the microtech still seem to run wasteged spark. You could check this with a snap on timing light - (Just check the rpm and see if its double the actual rpm). Its time to scope the ignition drive and see whats happening. Dont expet to see the dwell time to exactly matched the software dwell time but it should be within +/- 0.2ms. I dont know whether the skylines are a positive or negative trigger but you may find that the oppisite of what it should be is occuring on cyls 3 and 4 causing incorrect dwell control (acually from the r33 transistor diagrams it looks like a positive trigger). IF you have a 2 channel scope compare the microtech ignition drive of say coil 1 vs coil 3 and see what you get.

[rob82]

Hmmm i'm starting to think that myself. I went for a blat this afternoon for a few hours trying to sus out any other niggly problems and got home and opened the bonnet and there is silicon on the side of 3 and 4 coilpacks just near the plug. Just pulled number 3 out to inspect then and it's got a tiny little crack on the side of the coil and i presume 4 would have the same!

Perhaps i should change the dwell timing from 2.5 to lower?

At 3000rpm the duty cycle on the coils with a wasted spark setup at 2.5ms dwell is 12.5%, as in 12.5% of the time the coils are on and 87.5% the coils are off. Cant see that this amount of dwell wasted spark or not is going to cause them to fry.

There is a possiblility that timing on those two cylinders is incorrect as well!

[Adriano]

Yes, i wonder if 2.5ms is too much when run in wasted spark?

[Adriano]

Except it is still double the recharge time(or less than half the discharge/cooling time than stock. AFAIcan remember the stock dwell is 2.2ms, and reduces slightly at idle

[rob82]

Except it is still double the recharge time(or less than half the discharge/cooling time than stock. AFAIcan remember the stock dwell is 2.2ms, and reduces slightly at idle

A race car with an Rb26 will average 6000rpm at the track and they dont melt coils with about the same dwell/recharge rate as a wasted spark system at 3000rpm.

You got issues and I dont reckon its dwell!! If the dwell is only 2.5ms.

[JET-25L]

Hmmm i'm starting to think that myself. I went for a blat this afternoon for a few hours trying to sus out any other niggly problems and got home and opened the bonnet and there is silicon on the side of 3 and 4 coilpacks just near the plug. Just pulled number 3 out to inspect then and it's got a tiny little crack on the side of the coil and i presume 4 would have the same!

Perhaps i should change the dwell timing from 2.5 to lower?

[JET-25L]

hmmm yeah i know PM-R33 uses an lt12 and his dwell is 2.5ms and has no dramas. Ahh i don't know what it could be. Might be time to give rxengineering from microtech a call and see if he knows anything. Something has me thinking it might be something fairly simple that maybe just wasn't setup quite right..

[JET-25L]

So they want me to send the computer back to them for a looksie so i'm probably going to do that...

So the computer controls all the feed to the coilpacks right... and rob82 u were saying with a wasted spark setup.. 1 and 2.. 3 and 4.. 5 and 6.. ? So would that lead you to believe that there's something wrong with the 3 and 4 driver and send the computer back to check?? Coz there's nothing else that it could really be?

Anyones opinions?

[James_03]

So they want me to send the computer back to them for a looksie so i'm probably going to do that...

So the computer controls all the feed to the coilpacks right... and rob82 u were saying with a wasted spark setup.. 1 and 2.. 3 and 4.. 5 and 6.. ? So would that lead you to believe that there's something wrong with the 3 and 4 driver and send the computer back to check?? Coz there's nothing else that it could really be?

Anyones opinions?

The ECU pulses a ground trigger to the coils in order to fire them. You have 3 terminals on the coils usually, 12+, Negative, Trigger. The coils don't ground out via the ECU, as that would kill it. Instead the negative trigger from the ECU is responsible for opening the ground to that particular coil. So to put it simply, the ECU is just flicking an on/off switch inside the coils, then the coil grounds out via the common ground that they are all using.

What are the condition of the other coils? Are they showing any signs of heat damage or is it just 3/4?

One thing you could do to test, is remove the CAS and get someone to spin it around with IGN on. Remove the plugs from all the coils packs, put the multimeter on say CYL 2 and measure the current output from number 2 when it fires.

Then do the same for plug number 4, check what the current output is when it fires and compare. Keep all the results from that test, then plug the stock ECU back in and do the same thing again. Also check the trigger wire output between cyl 2 and 4 then compare for both ECU's.

This should tell you if the trigger on the microtech has too much current, and also if the issue lies between just the 3 and 4 driver on the microtech.

The problem should show on the muti between the good/bad coils, if there is one. I think what you *MAY* have ran into, is an incompatibility between the 16 and the integrated ignitors with the S2 coils.

Post up on the Microtech EFI forums too, there's a couple of guys on there that are quite good.

Edited August 5, 2009 by James_03

[JET-25L]

Yeah i posted up there. Was talking to jon from rxengineering as well and he thinks there's something sus with the driver for ignition 3 and 4 and recommended to send it back. Think this has also had a drama on my plugin board as well because two of the pins seem to have melted and merged.. Don't remember if it was like this to start but it looks a bit sus. Hopefully it gets fixed under warranty as i have used it for less than about 5 hours total and i believe something was sus with the driver to begin with. Microtech will tell me if there's anything up with it soon enough. Will let you know the results incase anyone else has the same drama!

Drove around all day with standard computer in and the cracks on the coilpacks on 3 and 4 didn't change so defo seems something up with the computer. All the other coilpacks are perfect i checked them many many times.

For the record i think the microtech runs the car beautifully while it is going!

Steve

[rob82]

So they want me to send the computer back to them for a looksie so i'm probably going to do that...

So the computer controls all the feed to the coilpacks right... and rob82 u were saying with a wasted spark setup.. 1 and 2.. 3 and 4.. 5 and 6.. ? So would that lead you to believe that there's something wrong with the 3 and 4 driver and send the computer back to check?? Coz there's nothing else that it could really be?

Anyones opinions?

I'm pretty sure the LT12's have 6 igntion drivers however for some reason and I can only comment on the lt12's I've seen that they run wasted spark. So even if you wire in to 6 drivers you only get 3 - so they probably just bridge them internally meaning that cylinders 1 - 6 , 2 - 5 and 3 - 4 fire at the same time(ie 1 cylinder is on compression the other on exhuast stroke).

The way most ecus work is to power 1 side of the coil with the negative side of the coil going back to the ecu. So the coil is energised when the igntion driver grounds the coil for x amount of time, with x being the dwell on the coil. The coils in skylines however have an igntion feed, ground and trigger. The trigger dependig upon the coil can be negative or positive and for skylines I cant remember if its a positive or negative.

To me it sounds like the drivers for cylinders 3-4 are oppisite to the other drivers meaning that instead of having 12.5% on time at 3000rpm you have 87.5% on time - scary!!!

[JET-25L]

So with all of that in mind^^ you would be thinking there's a fault with the computer somehow?

[JET-25L]

RESOLVED:

Sent computer to microtech.. They said computer is fine but the dwell was set to time based and it should be cycle based so they changed the setting for me. Blamed us for changing it however we never touched the dwell so i believe it was like that from the start but who knows. But anyway problem solved no more cooking coilpacks. What a pain in the arse for about 2 clicks! $60 bucks including return delivery = nothing. Although i woulda liked 6 splitfires instead of the 4 i have now!

Steve.

[Adriano]

Interesting, as time based is what i have them set to, otherwise the coils melt at idle.

[N I B]

The Timing a Microtech thinks it has and really has is very different ,Be very careful when tuning ignition on the things.