M30 OEM Turbo project

[CorvallisBMW]

I'm still gonna have to say start with the 02 and coolant sensor if those don't fix it which I feel like it would. If it's the coil maybe go to a wasted spark setup?

I'm not going wasted spark yet, as that would require an entirely new EMS setup. For now I'm just going to try a used coil.

They all seem plausable. It almost sounds like some sort of warmup enrichment problem. 10's are super rich. Hows the ICV, is it opening properly and seem to be working? Possibly stuck and the idle only improves when the motor warms up? What are the AFRs when the motor is warm?

ICV appears to be working well, though I have a spare I can swap out.

When warm I usually see AFRs in the high 14s, so just about perfect. Occasionally after driving and then coming to a stop I'll see it dip down to the high 10s, but it recovers in a few seconds and the idle quality or speed never seems affected.

Oh, and I'm also fighting this problem: http://www.r3vlimited.com/board/showthread.php?t=362751

They don't seem related, but stranger things have happened.

[ZenitramNaes]

They all seem plausable. It almost sounds like some sort of warmup enrichment problem. 10's are super rich. Hows the ICV, is it opening properly and seem to be working? Possibly stuck and the idle only improves when the motor warms up? What are the AFRs when the motor is warm?

[ThatOneEuroE30]

I'm still gonna have to say start with the 02 and coolant sensor if those don't fix it which I feel like it would. If it's the coil maybe go to a wasted spark setup?

[CorvallisBMW]

Well if I unplug the sensor when it's warm, there's a definite drop in idle quality. So it's sending some kind of signal to the ECU, but who knows if it's the correct one.

I did more testing tonight and noticed a couple of things. First, the idle goes from shit to perfect right at about 120F engine temp. That seems to be the magic number. Second, my old ECU with the sssquid tuning chip has the same shitty idle that the Miller one does, yet it was perfect pre-turbo. Third, my AFRs while idling shitty are in the low 10s. Not great by any means, but also not blowing clouds of smoke/undriveable/barely running bad.


I have a couple of theories:

1) my coil is going out, so it's unable to provide enough spark energy when the engine is cold, causing poor idle. Once the engine hits about 120F, the fuel vaporizes more readily and the weak spark does a better job of lighting the mixture. Dan Miller said that these could fail often, but fail slowly, on m30 turbo cars due to excessive heat.

2) my O2 sensor heater is bad, meaning it's providing an incorrect signal to the ECU until it is warmed up naturally by the exhaust and warming engine.

3) somehow the coolant temp sensor is bad, even though it ohms out perfect.

Thoughts?

[ZenitramNaes]

For what it's worth, when I upgraded to the FMIC from the the fendermounted IC I expected a much larger lag. I added a decent amount of pipe considering I didn't flip the TB (planning on it soon) but I didn't feel any additonal lag whatsoever. In fact, it felt much more responsive, however I beleive that's due to the fact I brought all the smaller pipes to a consistent 3 inches.

Good luck on your rich idle hunt. In my experiece with a bad temp sensor, it wouldn't run/idle once the car warmed up. Would completey bog out and stall in revs. If you unplug it and you notice a difference than chances are it's fine.

Good luck and I hope it's something easy.

[AndrewBird]

lol, that pump that comes with that water-to-air intercooler kit is a bilge pump for a boat. I guess use whatever works.

[CorvallisBMW]

Very true. I could conceivably use the Mishi unit you posted, with a 90* elbow on one end and keep my current TB location. If I necked the 2.5" IC tanks down to 2" to match the factory pipes and turbo size, it would be easier to route.

Just some ideas I'll have to ponder over the winter I guess. I don't want to tear in to it now with summer in full swing, I'd rather focus on driving and enjoying.

In other news, I've been pushing to find the cause of my shitty, rich cold idle. I plugged my old sssquid 91 octane chip in, and low and behold the terrible idle remains. So it's 100% not the tune that's causing it. I'm beginning to wonder if it's the O2 sensor, as I haven't changed it since 2007. There's also a chance my temp sensor is bad, even though it ohms out OK. So I ordered new O2 and new temp sensors, which I'll install one at a time to see if I can drill down on the root cause. I also need to figure out why my TPS was acting up.

[ThatOneEuroE30]

I was gonna suggest that. But I feel like with a bottom mount turbo and a fmic with a flipped Tb that should cut a lot of piping out. Maybe not so much for you with AC but with out it I know it should.

[CorvallisBMW]

Ya, no matter how you hash it any FMIC will have a lot of extra piping, whether the entrance/exit are on the same side and you keep the factory TB location, or flip the TB and use a traditional IC.

I've also been considering one of these:

http://www.siliconeintakes.com/front-mount-intercooler/water-to-air-intercooler-p-1034.html

Air/water has several distinct advantages including better efficiency, much lower pressure drops, smaller footprints, and less susceptibility to heat soak. Nearly all OEMs are air/water nowadays.

[ThatOneEuroE30]

M30 OEM Turbo project

But wouldn't that just add to the lag from the intake pipes not being flipped?

This is the Intercooler I'm gonna run

http://m.mishimoto.com/ystore/yhst-62631657248580/mishimoto-universal-intercooler-small.html#0

[CorvallisBMW]

So I did some internetz last night and found these:

http://www.treadstoneperformance.com/product.phtml?p=86216&cat_key=63&prodname=TRV185++Series+Intercooler++720HP

http://www.treadstoneperformance.com/product.phtml?p=68301&cat_key=63&prodname=TR62+Intercooler+450HP

They're a little "oversized" as per their max hp rating, but I don't think that would have too much of an ill effect, besides possible adding a bit of lag as the turbo works to pressurize the extra volume. Plus even with the same-side inlets/outlets it would still be a challenge to get all the piping to fit with my A/C intact. But it would allow me to keep the factory TB position and factory intake pipe, which I admit is more about looks than anything else.

[ThatOneEuroE30]

Ha I'll be doing the same. Good to know the regular IC isn't even worth the hassle

[CorvallisBMW]

I don't know if you're stilling using the 745i intercooler but FYI, before I upgraded to a much larger FMIC I was running the 745i intercooler with my k27. It was placed near the stock location on the passenger side of the bay. I saw intake temps as high as 150 degrees which wouldn't come down once it got heat soaked. Fast forward to the FMIC the highest I've seen is about 10 degrees above ambeint on a summer day.

I know you're trying to do the whole OEM build and I respect that. Maybe look back into finding a velocity stack that will work for the passenger headlight delete in order to bring the temp down a bit?

Honestly I've put about 20 miles on it with the thermocouple to monitor temps, and I'm seeing exactly the same thing. Once it gets heatsoaked, there's nothing that can be done to fix it short of 5+ highway miles, and even then it's not much better.

I think what I'm going to try doing is taking it out completely and running non-IC for now (not really that dangerous on 6psi) and then, over the winter, buying another intake manifold and going flipped-TB and FMIC.

[ZenitramNaes]

I don't know if you're stilling using the 745i intercooler but FYI, before I upgraded to a much larger FMIC I was running the 745i intercooler with my k27. It was placed near the stock location on the passenger side of the bay. I saw intake temps as high as 150 degrees which wouldn't come down once it got heat soaked. Fast forward to the FMIC the highest I've seen is about 10 degrees above ambeint on a summer day.

I know you're trying to do the whole OEM build and I respect that. Maybe look back into finding a velocity stack that will work for the passenger headlight delete in order to bring the temp down a bit?

[delamaize]

Sadly no burnout vids :(

I need to find a set of bottlecaps and shitty tires, then I'll be ready to go :)

I got the shit tires for you, camber worn piles of fuck that need to die. You just need to find some wheels to put them on.