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.

[george graves]

Science-y stuff!

I found these badass thermocouples on eBay for $10/each

Those are interesting! My 2 cents. They look as delicate as all hell. One knock on them and the seal/weld is broken. Not fun! Since you're measuring air, the key is small thermal mass. That's the most important thing. These sensors are not. The tubing and build are huge thermal masses with heat sinks attached - in effect - to measure the surrounding environment(the long tubing is going to be a heat sink - getting cooled or warmed by the outside air in the engine bay - depending if your stuck in traffic, or doing 90). Those would be better at measuring water temps on a boat engine room, then air for a inter-cooler I would think.

[CorvallisBMW]

Ya, I was kind of thinking about that, but IIRC thermocouples only measure temperature at the point where the two doped wires cross, i.e. right at the tip. If my understanding is correct this should negate the effect of the long metal body. But I suppose I should try heating the body and then sticking an ice cube on the tip ( :giggle: ) just to confirm

[CorvallisBMW]

George you were right, the metal body picks up quite a bit of ambient heat. I used a lighter to heat the metal body near where it connects to the braided line, and it caused the temp reading to rise pretty fast.

Oh well, it was worth a shot :(

I can make some out of standard thermocouple wire and try to insert them in to the airflow through the rubber couplers, those would have little if any thermal mass.

[CorvallisBMW]

I'm still facing a driveability issue related to WOT. If I stomp on the pedal or push the throttle to WOT, the engine just dies super fast. I also see my AFRs go to max, which means no fuel.

This has me thinking that either there's something goofy in the wiring between my TPS and the ECU that's causing a bad signal and telling the ECU to cut fuel when it should actually be pushing more fuel, or that my 24-year-old m20 fuel pump is just struggling to respond to the instant demand of 36lb/hr injectors when it normally supplied 15lb/hr units.

[staysideways]

I'm still facing a driveability issue related to WOT. If I stomp on the pedal or push the throttle to WOT, the engine just dies super fast. I also see my AFRs go to max, which means no fuel.

This has me thinking that either there's something goofy in the wiring between my TPS and the ECU that's causing a bad signal and telling the ECU to cut fuel when it should actually be pushing more fuel, or that my 24-year-old m20 fuel pump is just struggling to respond to the instant demand of 36lb/hr injectors when it normally supplied 15lb/hr units.

Yea sounds like fuel pump cant keep up or you dont get enough spark

1989 E30 325i Sedan Alpine

[CorvallisBMW]

I rented a fuel pressure tester over the weekend and followed all the tests in the Bentley to test for flow and pressure. Everything checked out perfect, zero issues.

I also changed out the coil and ICV. Again, zero changes.

So now I'm starting to wonder if it's more airflow related. A malfunctioning MAF could cause the engine to add too much fuel on idle (if it was reading high) and too little fuel at WOT (if it was reading low). I know the wiring is solid, and the MAF appears to be working but it's hard to be 100% because Miller offers no real troubleshooting. I do know that if I unplug it it drives significantly worse, so it's at least doing something.

Part of me keeps coming back to the TPS though. It could also cause too much fuel at idle and too little at WOT. And when I test for continuity between it and the ECU per this diagram, I'm not getting any at all (open circuit). This seems incorrect, yes? THe ECU is the #6 block, so I should be seeing 0 ohms between pin 2 and the brown/blue wire, and 0 ohms between pin 3 and the brown/black wire, yes?

[ThatOneEuroE30]

I thought that the tps and Ecu should be in constant circulation?

[CorvallisBMW]

Here's the Miller-developed tune that I have. WOT fuel is 150 across the board, though I never use this one b/c the on/off throttle transition is absolute shit. https://drive.google.com/file/d/0B4v...ew?usp=sharing

And here's the one I got from another r3v member running a similar setup. It's the one I've been going off of 99% of the time. 255 fuel at WOT across the board.

https://drive.google.com/file/d/0B4vP9afE06OqY25CbVFSbWpLV3c/view?usp=sharing

If the files don't work, I can probably do screenshots... slowly

I tested the old AFM w/ my sssquid tuning chip. Same exact problems: horrible, rich cold idle and inability to go WOT.

Plugged the MAF and WAR back in, still behaving like a bitch. I did notice though that if I unplug the TPS, I can go WOT just fine, no problem. The idle is weird, but WOT works. This is basically what I was running on for about a month when I snipped the WOT trigger wire on the TPS harness; it had an idle signal but not a WOT signal, and it ran OK aside from the too-lean condition at WOT (obviousely). Clearly not a resolution to the underlying issue, or a long-term fix. But it's one more piece of the puzzle.

Video: https://vimeo.com/135318837

[2mAn]

Why not get the car tuned properly on a dyno?

[CorvallisBMW]

At this point it won't even rev, I can't dyno it. I have to fix whatever is causing all the shit before I can really start tuning.

[staysideways]

Is the top suppression plug on your coil good? I had the same backfiring/antilag bullshit problem when the suppression plug to my car was all croded and snapped check that even if its new. Also if it is that it could be that you have too much resistance that you are frying the plug/wire.

Also my experience was in my M20B25 so idk if you have a similar setup as the m20 does but to me it sounds alot like spark issue. Keep in mind you can always do a smoke test and see if you have a vaccum leak

1989 E30 325i Sedan Alpine

[CorvallisBMW]

Well guys, I have some news... Not sad, but not what I was hoping for either.

I've been fighting with the Miller stuff now for months, and nothing seems to be working. They (Miller) swear it's because I need to spend $400 on their newest-gen MAF. But everyone I've talked to, and I mean everyone, says that the entire system is inferior to MS anyway. So, to break it down:

Cost of going to MS: $650 (whodwho PnP system)
Cost of fixing Miller: $400

Why am I even debating this??? The Miller stuff is getting sold off and I'm going MS. I know that in the end it will be so much better, and very much worth it. The bummer is that it's not going to happen this summer. So, sadly, the car is going back in the garage (it's only august!!) while I plan out my MS and FMIC journey for the coming winter.

So, no big burnouts or anything...yet :evil: Next year....

[Bearmw]

Sounds to me like the end result will be well worth the wait.

[Good & Tight]

Well guys, I have some news... Not sad, but not what I was hoping for either.

I've been fighting with the Miller stuff now for months, and nothing seems to be working. They (Miller) swear it's because I need to spend $400 on their newest-gen MAF. But everyone I've talked to, and I mean everyone, says that the entire system is inferior to MS anyway. So, to break it down:

Cost of going to MS: $650 (whodwho PnP system)
Cost of fixing Miller: $400

Why am I even debating this??? The Miller stuff is getting sold off and I'm going MS. I know that in the end it will be so much better, and very much worth it. The bummer is that it's not going to happen this summer. So, sadly, the car is going back in the garage (it's only august!!) while I plan out my MS and FMIC journey for the coming winter.

So, no big burnouts or anything...yet :evil: Next year....

Great choice moving to MS, you will have more tuning parameters and options than you will ever need, and very user friendly. And most importantly the best tech support.

And
I'll be honest I have yet to hear one success story on the Miller stuff.