Single turbo supra auto - hesitation on WOT... help!!

[and1c]

ok guys.

Got back on to the car now the weather has picked up a bit.

 

 

Brief spec - Titan stage 2 auto, 3800 hi stall

refreshed engine with all ARP hardware

Link ECU

PT 6768 dbb turbo

800 cc sard injectors

Dynoed at 495 rwhp Dyno Dynamics previous to my ownership

 

So I have been through the car pretty much completely and it has wanted for nothing... All usual things have been attended to (in addition to many others lol) and it runs sweetly except for if I get on the gas hard, then I get random hesitations/misfire possibly.

 

It seems to be at 1 bar boost near enough. It doesnt go much above this due to the above and I dont keep pressing on.

 

What I have done,

new NGK BKR8EIX

Gapped to .024 thou, Nero at Titan recommends 0.025 as good for the vast majority of single supras, some running much higher boost.

I have redone all of the coil pack wiring as far back as possible , with new wiring and new connectors.

It has super spark coil packs that are nearly new and are not the problem.

I have boost pressure tested the system to 18psi (that's what the dump valve opens at)

 

I am kind of out of ideas and it is starting to p*ss me off!! If I go steady on the throttle it goes like a rocket (slow increase) but at some point usually above 5000 rpm it will stutter.

 

AFR gauge fitted, it's hard to tell exactly as it doesn't always do it (depends on driving style) but seems to be about 12:1, although I glanced and saw it at 10.3 under wot.

 

Could the standalone be at fault? It could be the map, I have no way to be certain apart from it was running fine for the last owner apparently and it had no spec changes since the dyno chart.

 

 

 

 

I wonder if it is worth redoing the coil wiring all the way back through the loom. Could be another waste of time though!!

If I had a good specialist locally I would undoubtedly take it there as I dont have time for it at present.

 

Anyone got any ideas on where to go next? thanks

 

 

ps/ Could it be trac control related?

Edited April 5, 2017 by and1c (see edit history)

[Wez]

Can you not pull logs from the ECU?

 

Is it full standalone or running piggyback?

 

Also, didn't think you need to gap Iridium plugs, in fact it's best not too as can weaken the the tip.

[and1c]

It's a Link G3 LEM mate, I don't believe it does log recording, only logging while you have a laptop hooked up..! And it's hard enough reading the gauges at wot.

It is full standalone, running the 2j auto ECU only for auto box functions.

 

I thought you didn't have to gap them either!! I rang Norris motorsport who are the nearest 'quality' place to me to see if he could take a look, (he wouldnt! as they do EVO or cosworth not 2jz..) But he was saying what are the plugs gapped at? I said they were not gappable and were preset Iridiums I thought. He advised me that they gap them all the time for higher hp turbo motors, and they ARE totally gappable.

So I duly removed them this evening, gapped them very very carefully and refitted. It made naff all difference sadly!

[and1c]

I think if I pay to update the firmware to the Link G4 then I can do logging... may be worth exploring but then the map needs 'porting' to the G4, though I guess this is manual replacement of all values that were present in the old setup

 

Oh and I compression tested it just to be sure and they are all 180psi give or take a couple of psi

Edited April 5, 2017 by and1c (see edit history)

[Chris Bailey]

How do you know for definite it's not the super spark coilpacks? They are prone for causing missfires.

[and1c]

How do you know for definite it's not the super spark coilpacks? They are prone for causing missfires.

 

Really??

Hmm, I dont know for sure!! but they look brand new, no cracks or heat damage, and they cost the last owner £400! I was reading up on them and found only good stuff?? You think it may be them>?!!

[and1c]

Although one thing I don't like about them is the little springs that go on to the plug, they dont line up straight in the rubber sleeve, and nor do they actually loop over the top of the plug as I tried it when they were removed earlier!!

Edited April 6, 2017 by and1c (see edit history)

[Chris Bailey]

Really??

Hmm, I dont know for sure!! but they look brand new, no cracks or heat damage, and they cost the last owner £400! I was reading up on them and found only good stuff?? You think it may be them>?!!

 

We had a set fitted for about a year, They were fine on medium boost (1.4bar) but when we turned the boost up to 1.8bar on dragonball for abit of fun, the first time we went on boost its missfired badly at 5000rpm. Swapped the coilpacks for brand new OEM that Lee at SRD had with him the same evening and it's been fine ever since. Also the super spark ones we removed looked in brand new condition.

[and1c]

We had a set fitted for about a year, They were fine on medium boost (1.4bar) but when we turned the boost up to 1.8bar on dragonball for abit of fun, the first time we went on boost its missfired badly at 5000rpm. Swapped the coilpacks for brand new OEM that Lee at SRD had with him the same evening and it's been fine ever since. Also the super spark ones we removed looked in brand new condition.

 

Thanks Chris!!!

Did some more searching after you said they were notorious and found this http://www.mkivsupra.net/vbb/showthread.php?313009-missfire-under-boost-faulty-coil-pack&highlight=super+spark+coil

it seems Lee has had a lot of issues with them

 

Anyone got any idea on the cost of a new set from SRD?

 

Thanks again mate, I pray that this solves it

[and1c]

Anyone know if these are just black super sparks?

http://www.garagewhifbitz.co.uk/toyota/supra/ignition-parts/garage-whifbitz-568.html

[Chris Bailey]

Thanks Chris!!!

Did some more searching after you said they were notorious and found this http://www.mkivsupra.net/vbb/showthread.php?313009-missfire-under-boost-faulty-coil-pack&highlight=super+spark+coil

it seems Lee has had a lot of issues with them

 

Anyone got any idea on the cost of a new set from SRD?

 

Thanks again mate, I pray that this solves it

 

OEM coils are about £600 a set. Might be worth seeing if anyone has a second hand set you could maybe buy/borrow.

[and1c]

OEM coils are about £600 a set. Might be worth seeing if anyone has a second hand set you could maybe buy/borrow.

 

Cheers, borrowing a set is a good plan if anyone happens to have a spare set for sale!? or loan!£!

Otherwise I will do further research on the options for coil packs

[Mk4Gaz]

I've got a set of oem coil packs here, that were perfect on my car at bpu levels.

Then I went single, and as soon as we turned the boost up to 1.4 bar, I started getting misfire problems.

So, I bought a brand new set of benchmark coil packs, and I've still got the same problem - in fact, the exact same issue you have!

Before I go and spend an inordinate amount of money on a set of oem coils, I'd like to rule mine out, in case it's something else.

I'd be happy to send you my oem ones to try, to see if it cures your issue? Whilst it may seem like a waste of time, at least it might rule those out

I too am using bkr8eix plugs - although I haven't tried to re gap them

 

 

[and1c]

I've got a set of oem coil packs here, that were perfect on my car at bpu levels.

Then I went single, and as soon as we turned the boost up to 1.4 bar, I started getting misfire problems.

So, I bought a brand new set of benchmark coil packs, and I've still got the same problem - in fact, the exact same issue you have!

Before I go and spend an inordinate amount of money on a set of oem coils, I'd like to rule mine out, in case it's something else.

I'd be happy to send you my oem ones to try, to see if it cures your issue? Whilst it may seem like a waste of time, at least it might rule those out

I too am using bkr8eix plugs - although I haven't tried to re gap them

 

/QUOTE]

 

HI Gaz, thanks mate. That sounds like a good plan. I will of course cover postage both ways.

Likewise, I am reluctant to fist £600 notes to Mr T if that turns out to not be the issue!!

Will drop you a pm.

[Wez]

I've got a set of oem coil packs here, that were perfect on my car at bpu levels.

Then I went single, and as soon as we turned the boost up to 1.4 bar, I started getting misfire problems.

So, I bought a brand new set of benchmark coil packs, and I've still got the same problem - in fact, the exact same issue you have!

Before I go and spend an inordinate amount of money on a set of oem coils, I'd like to rule mine out, in case it's something else.

I'd be happy to send you my oem ones to try, to see if it cures your issue? Whilst it may seem like a waste of time, at least it might rule those out

I too am using bkr8eix plugs - although I haven't tried to re gap them

 

/QUOTE]

 

What ECU are you running?

[Mk4Gaz]

What ECU are you running?

Hks fcon gold vpro bud

 

 

[Wez]

HI Gaz, thanks mate. That sounds like a good plan. I will of course cover postage both ways.

Likewise, I am reluctant to fist £600 notes to Mr T if that turns out to not be the issue!!

Will drop you a pm.

 

Just looked at the spec of your ECU, Link G3 LEM and for 6 cyl operation it runs wasted spark as it only has 4 ignition outputs, has this ever worked at the boost you are trying to run?

 

http://forums.linkecu.com/applications/core/interface/file/attachment.php?id=2542

 

I had similar issues with the AEM PnP many years ago and its why you had to use a HKS DLI which is basically an ignition amp to boost the spark, without it you could not boost over 1 bar even on stock twins.

[jcbt]

We had a set fitted for about a year, They were fine on medium boost (1.4bar) but when we turned the boost up to 1.8bar on dragonball for abit of fun, the first time we went on boost its missfired badly at 5000rpm. Swapped the coilpacks for brand new OEM that Lee at SRD had with him the same evening and it's been fine ever since. Also the super spark ones we removed looked in brand new condition.

As Chris said ours was coil packs- I could build speed up slowly to about 5k revs and then would badly misfire so my initial thought would be coil packs - if on the other hand it's a bit like Kangaroo effect and feels like it's holding back it could be boost control solenoid. But looking at your circumstances I would put money on those coil packs being your problem.

[and1c]

Just looked at the spec of your ECU, Link G3 LEM and for 6 cyl operation it runs wasted spark as it only has 4 ignition outputs, has this ever worked at the boost you are trying to run?

 

http://forums.linkecu.com/applications/core/interface/file/attachment.php?id=2542

 

I had similar issues with the AEM PnP many years ago and its why you had to use a HKS DLI which is basically an ignition amp to boost the spark, without it you could not boost over 1 bar even on stock twins.

 

I have not had the car running properly above 5k rpm , no! I am assuming it used to because Chris Wilson did quite a lot of work on the car before I bought it and said it ran sweetly, but I don't know if he had tested it to the extent I have. Since then it has been rebuilt pretty much. I wonder if there is already a 'faulty' ignition amp on the car? I cant see how it would dyno at nearly 500 rwhp with this issue, it is not possible.

Will do some more hunting in the footwell and see if there is one that may be faulty?

Cheers Wez

[Wez]

Are you 100% sure on ECU model, as the normal LinkPlus G3 has sufficient ignition drivers. I had not heard of the G3 LEM until you mentioned it.

[and1c]

Are you 100% sure on ECU model, as the normal LinkPlus G3 has sufficient ignition drivers. I had not heard of the G3 LEM until you mentioned it.

 

Yes mate, I'm 99% sure. The G3 LEM is the cheaper version of the G3 (G3 does full sequentia injection I think?)

I've just checked inside it and it says G3 LEM on the PCB, the case is the same as the G3 though..!!!

That means that I must have an ignition amplifier somewere.....??? right?!!

 

edited// Apparently the G3 is the Same as the G3 LEM according to Link. One and the same ECU,

 

G3/G3LEM is the same thing. Yes you will need an ignitor or coils with a builtin ignitor.

The G3 to G4 firmware upgrade is a relatively simple process, there is a charge for the upgrade "code". You can buy that through a dealer or possibly direct of us.

Edited April 7, 2017 by and1c (see edit history)

[Wez]

Yes mate, I'm 99% sure. The G3 LEM is the cheaper version of the G3 (G3 does full sequentia injection I think?)

I've just checked inside it and it says G3 LEM on the PCB, the case is the same as the G3 though..!!!

That means that I must have an ignition amplifier somewere.....??? right?!!

 

For a 6 cyl engine that ECU has to run wasted spark, that is of course if its driving the coils as you are auto with the link running piggyback arent you?

[and1c]

For a 6 cyl engine that ECU has to run wasted spark, that is of course if its driving the coils as you are auto with the link running piggyback arent you?

 

Yes indeed. Just been looking through the ignition tables and dwell settings. It is set up as wasted spark, 3 pairs. Meaning there should be an ignition booster...? somewhere! But I have fitted a new engine and had the entire engine loom out to redo connectors and when I did the engine and I have seen nada, zip, nothing!!

 

- - - Updated - - -

 

The problem is becoming clearer lol

 

Is it worth checking the voltage at the coil positive with the engine running? Realistically I doubt it will tell me squat because the car runs sweetly until 5k rpm / higher boost

Edited April 6, 2017 by and1c (see edit history)

[Wez]

If it were mine I would be speaking to a Link dealer / installer.

 

I am going on experience with the older AEM PnP units that also ran wasted spark, the fix was a HKS DLI, it was well known and documented in the US and UK, I even tried with and without on mine with stock JSpec twins and then a single.

[and1c]

Yes, that sounds like a plan..

Will do so and update