Engine build

[Kjewer1]

If it would give a single cylinder misfire I could move parts around and see if it follows, but no such luck.

Just tried the other set of coils, no luck. That car's factory plugs are next.

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[Tune+]

The only issue I'm having at this point is a strange surging at WOT, feels like the power comes and goes at about 2hz. When it gets real bad it's more like a misfire and I can just barely hear some noises from under the hood. If it's knock (doesn't sound like it to me) the ECU doesn't seem to be picking it up. It did it before the motor swap, and does it on the Cobb tunes as well. Changing plugs has always fixed it in the past (been through at least 10 sets in 3500 miles, 3 more since the motor swap), but it always comes back. It does seem to get worse with higher boost and better with lower boost. 93 octane or E30 makes no difference.

The owner of that Skyline in the pic is bringing his EBM over. I'm going to steal all of his coils and see if anything improves. I'm meeting a friend at the track tomorrow to use his IDS to relearn the crank sensor/misfire profile. I don't think that's the cause but it's probably a good idea after putting another motor in the car. Other than that I'm out of ideas. Searching here turns up all kinds of threads about misfires, but solutions seem scarce. I'm open to ideas! Hopefully someone else has dealt with this and solved it. The car has been plagued with it since new and it's time to sort it out.

Sounds like you need some small adjustments in the tune. There are a few clips I can think of off the top of my head that might be giving you issues. I can look at a log and tell you, drop me an email and I'll send you over some parameters to check out.

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[Kjewer1]

I'll probably take you up on that Adam. It does it on the Cobb tunes too though, is that something people commonly experience with those? On Cobb stage 0 there are all kinds of throttle closures and boost recuctions but I can't feel a single one of those. On the highest boost tune I have there are no throttle closures or boost reductions and I feel like I'm riding a bucking bronco.

 

[Tune+]

I'll probably take you up on that Adam. It does it on the Cobb tunes too though, is that something people commonly experience with those? On Cobb stage 0 there are all kinds of throttle closures and boost recuctions but I can't feel a single one of those. On the highest boost tune I have there are no throttle closures or boost reductions and I feel like I'm riding a bucking bronco.

Let's log the bucking bronco one, and we'll figure it out.

 

[Kait]

Very detailed, nice work.

Im surprised no one brought up that gorgeous R32 Skyline sitting outside his garage.


I know its off topic, but I'm sure some people here (namely myself lol) Would care to know the details behind that car lol.

EDIT: Someone beat me to it.


Care to share the details? More importantly, how is that thing wearing legal plates? Surely it can't be 25 years old yet. Or is it?

She's gorgeous! :hail:

 

[Kjewer1]

So, in a strange turn of events, the stock plugs seemed to fix it. Stock gap and all. Strange that all those sets of 6510s and ITV22s didn't work, and these do. I loaded up a 29 psi tune for pump gas and no issues there either. On the last (5th or 6th) pull it did it slightly, but at a 31 gap or whatever, I can't really be surprised. Idle is still a little rough without bshafts etc, but no obvious misfires at idle.

So just like before the motor swap, plugs are the only thing that seem to make a difference. Not sure if this is good or bad.

 

[Tune+]

So, in a strange turn of events, the stock plugs seemed to fix it. Stock gap and all. Strange that all those sets of 6510s and ITV22s didn't work, and these do. I loaded up a 29 psi tune for pump gas and no issues there either. On the last (5th or 6th) pull it did it slightly, but at a 31 gap or whatever, I can't really be surprised. Idle is still a little rough without bshafts etc, but no obvious misfires at idle.

So just like before the motor swap, plugs are the only thing that seem to make a difference. Not sure if this is good or bad.

29psi tune? You do realize that you are probably making more than 29psi and 29psi is the max the factory TIP and MAP can read. If your log has flat boost, you are maxing out the factory TIP/MAP. The bucking bronco feel was the ECU unable to transpose information for SD/CEQ.

 

[Kjewer1]

It peaks at 29 psi briefly, only around 3500 rpm, it immediately tapers down to low 20s by redline. The surging was at higher rpm where it was well under the 29 psi level. And again, it does this on the cobb tune as well, that peaks around 24 psi.

 

[Kjewer1]

It did also have a P0148 code when I got back. No CEL, I just happened to look. I'll have to log fuel pressure and related items tomorrow, but I'm not sure what they normally look like.

 

[Tune+]

It peaks at 29 psi briefly, only around 3500 rpm, it immediately tapers down to low 20s by redline. The surging was at higher rpm where it was well under the 29 psi level. And again, it does this on the cobb tune as well, that peaks around 24 psi.

Yea, probably peaking the map a bit. However up top SD is probably off due to your new VE. I think spark plugs might be a "ghost chase" and the problem is still there but comes and goes.

I hope you get it sorted out, again drop me an email if you want me to have a look and check some things.

 

[Edkiefer]

It did also have a P0148 code when I got back. No CEL, I just happened to look. I'll have to log fuel pressure and related items tomorrow, but I'm not sure what they normally look like.

Google says thats fuel delivered code , maybe hitting so high boost is throwing it , maxing out sensor .

 

[Kjewer1]

It's possible. I've never seen the code before all the times I've run boost in this range, but the way codes come and go on their own with this car there's no way to know if it's had it before or not. I normally wouldn't check with no CEL, but everything is under the microscope as long as it's not running right.

 

[EgoBoost]

No disrespect Kevin but it seems to me that you need to use more discretion with the boost and this motor. Seems like you've been taking risks even before the motor let go. Earlier today I was going to recommend giving Adam's tune a shot, but at this point I feel it's a no brainer. His knowledge/results speak for themselves.

 

[Kjewer1]

No disrespect taken! I appreciate all advice. I do take risks on my own cars. That how I got my Talon into the 7s (in the quarter mile, not in the 8th). I don't take risks on other cars however. I've tuned a thousand cars, from my own junk, to street cars, to 4 digit HP turbo V8s. This car is just one more shitbox in my driveway to play with. I learn by doing. And I've been doing this for 20 years. You didn't hear me complain about the stock motor breaking.

I'm also well versed in maxing out a given turbo. I've held turbo "records" on half a dozen different turbos and tuned many others. I also have what are probably the most successful examples of compound turbo charging on gasoline engines. My car has run 8.80 and 8.3 on two different compound setups. The car Kait races has run low 9s on compound turbos as well.

Just trying to give an idea of my experience and back ground. None of this is to say that Adam can't help me here. He's been tuning these cars and Cobb in general much longer than I have and he certainly a lot of this figured out.

If I haven't said it enough already, when the car has this problem on every tune, including the Cobb tunes that don't seem to give anyone else any trouble, I find it hard to believe the problem is in the tune. But we'll see if Adam can find something. No one wants this issue solved more than me. Next week is the last week of the season up here, I'd like to see a decent ET out of this thing before next spring.

 

[Kjewer1]

I realize I don't post a lot here and I'm not very well known, so here are a couple pics for clarity.

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