Noob M30B35 Build

[tig]

Little unclear but I think you are saying it won't run under about 1000 even with some slight throttle input?

Yes, and (often) won't start without throttle.

This morning it started right up though but the idle was just on the edge of stalling. "Lopey". I drove to get coffee and as soon as I pulled into the drive through it tried to stall when I went to idle.

Try monitoring the O2 sensor voltage as you let the revs fall and see if it pegs one way, either high or low voltage without dithering could indicate an extreme mixture problem.

I have a wideband. It does not appear to be overly rich or lean (13-15 range). Unlike on the b34, where i was using a single O2 sensor (the ECU was slaved off the wideband gauge) I now have 2 O2 sensors. One dedicated to the wideband and one for the ECU. FWIW.

When the revs fall there is a spike of lean.

This makes it sound like a mixture problem and not the idle control system. Best guesses are unmetered air either vacuum leaks or the AFM bypass screw way to far off, possible the AFM spring adjustment also but you've tried switching that already.

Good call. I will dig into this. The two AFMs behave slightly differently; I can't recall precisely how since it was 1am when I was doing it last night. But my spidey sense is tingling on this. I did baseline one of the two AFMs, I think the 1st one I tried. The one in there now was on the B34.

Generally I think it will sputter and cough if too rich and just falls flat like ignition switched off if too lean. A big old vacuum leak will drive it too lean and it will not run.

It's not lean, except sometimes when I come off throttle. Almost always rich and when it dies it sputters/coughs/feels-lopey.

Have you got a vacuum gauge you can stick on the manifold and see what you've got there also. That would give a clue since it should run maybe 14-20 range as you approach closed throttle and idle. If it's low it points to vac leak.

No; probably should invest in one. Any suggestions?

Your description of the fuel relay buzzing is also very odd. It should be either on or off. On if the rpm over 20 and off below. I suppose if the relay realy is buzzing on/off/on it could lead to fuel starvation. You might just jump the pumps and see if that makes it run then figure out what up with the fuel relay. Oh and if you are jumping the relay use your DMM and measure the current to the pumps to make sure thay are pulling proper power. Something like 6 amps IIRC.

See video: https://www.youtube.com/watch?v=PUfrV05aPXg

Bentley's says in-tank is 1.4 and main is 5.0, so 6 is about right. I get 4.

I swapped the o2 sensor heater relay and fuel relay. Buzzing stopped. Will toss that relay.

Of course when I go to video it, it fails to stall. But here's a video that shows the "lopey" idle.

https://www.youtube.com/watch?v=uW0HlA5KyDE

In the video you can see unplugging ICV has no impact on idle.

Unplugging CTS caused quick idle jump, so it's functioning.

Video shows wideband with some throttle blips.

FWIW, now that I've mucked with it, I haven't gotten it to stall, but it sitll is idling 'lopey'. I wonder if that's the paul burke cam in action?

[tig]

Just went for another drive.

It is running much better. Not sure why (other than swapping out the fuel pump relay).

However it still has a dip in RPM *almost* to the point of stall SOMETIMES when I let off the throttle.

Of course as soon as I tried to video it doing this it stopped doing it. Here's a video showing mixture at various throttle inputs. Note how when I let off the throttle the RPM stop abruptly at ~800 RPM as expected. When it goofs up they continue down to 200-300rpm and then the ECU compensates and they spike back up to 1500 or so. But, as I said, once the camera is running it refuses to reproduce.

https://www.youtube.com/watch?v=RiFVz68twiA

Note the B34 was doing this same thing when I had the Miller MAF installed.

[athayer187]

What fuel pressure are you running? I've noticed if I run too high (M30 B34, M1.3, 179 ECU with EAT chip, headers, otherwise stock) that the ECU can compensate and doesn't affect mixture as measured at the O2 sensor, but freaks out a bit during transitions to idle causing a dip. ~48-50 psi is the sweet spot for my motor.

[mitch5]

Have you tried unplugging the battery for a couple minutes yet to reset the ecu. I was have weird idling issues and stalls just like you were. I started to get balls deep into diagnostic when I remembered I might as well try the simplest thing first.

[Ron535i]

I have no idea if this will help or not, but I'll offer it up...

I have an 88 535i 5spd with the original B34 that I converted to M1.3 from an e32. I really like how this conversion helped with smoothing the idle and the drivability of the car. However, the one thing that it does that it did not do before is that when driving and coming to a stop, the Idle will very briefly dip to a point that you think it’s going to die, but then it quickly blips back up and then steadies at a solid 750 RPM. I have switched out several 179 ECU’s and they all do the same. I have talked to a couple of people who have done this conversion and theirs do the same. I figured it’s just a characteristic of running the M1.3.

Also, the M1.3/179 ECU is supposed to be adaptive, so your ECU may still be learning your motor.

[Ron535i]

What fuel pressure are you running? I've noticed if I run too high (M30 B34, M1.3, 179 ECU with EAT chip, headers, otherwise stock) that the ECU can compensate and doesn't affect mixture as measured at the O2 sensor, but freaks out a bit during transitions to idle causing a dip. ~48-50 psi is the sweet spot for my motor.

I just saw this... Having your fuel pressure set at that PSI eliminate the dip in idle during transition..?

*I'm not trying to thread hijack; I'm just trying to gain info and figured the OP could use the info also*

[demetk]

the Idle will very briefly dip to a point that you think it’s going to die, but then it quickly blips back up and then steadies at a solid 750 RPM.

I figured it’s just a characteristic of running the M1.3.

I don't have that idle dipping problem with any of my three b35's. Two of mine were converted to the manual TPS and the third is running the auto TPS with a 5-speed.

[pldlnr]

Drive the car for some more. The ECU needs to learn. I have experienced this with M1.3 in the past. When everything gets re-set, it doesn't run very well at first. It should keep getting better. But, I would at least give it time to learn before jumping into diagnosis/part swapping mode.

[wkohler]

That's racist.

[Ron535i]

I don't have that idle dipping problem with any of my three b35's. Two of mine were converted to the manual TPS and the third is running the auto TPS with a 5-speed.

Interesting... For clarification sake, are you running M1.3 on B35's or B34's..? Also, are your TPS' from a B34/M1.0 or B35/M1.3..? (I am using the TPS that was in the e32 that the rest of my conversion parts came from)

And as far as the "idle dipping problem"... I really don't consider it a problem because it is very slight when it happens. Maybe I'm more used to it now than when I first did the conversion, but I'm all ears if there's something I can do to prevent it...

[tig]

I drove Vlad the 18 miles into work this morning. A mix of freeway and downtown traffic. Damn, it feels good. I've enjoyed driving Maytag, but I didn't realize how much I missed the tightness of Vlad. I am very much in love with the clutch & shifter. The extra ponies and torque of the high-compression B35 ain't bad either. My new steering wheel makes me smile; it's got a great feel.

No stalls, but at almost every stop light I had the RPM dip and spike. That's my new term for it "the dip & spike". Never stalled, but threatened to a couple of times.

So perhaps the ECU is adapting. Something still isn't right about this though. Since I have an adjustable AFR I will try lowering the pressure. Hey, athayer187, if you watch my video you'll see the pressure...it's about 3.5 bar (about 50psi).

https://www.youtube.com/watch?v=uW0HlA5KyDE

Next time I get a chance I'll play with it some and report back.

FWIW, I don't think the dip & spoke has anything to do with the TPS.

Nothing has fallen off the car and there's no leaks. So far so good.

1. Re-check all fasteners and connections.
2. Bleed clutch slave again. I don't think I got all the air out.
3. Fix "dip & spike" when going to idle.
4. Install new throttle cable connection pieces (the old one's are barely hanging on).
5. Install the prototype of My B35 Intake Manifold Bracket.
6. Re-do spark plugs (don't ask; it's a long story that includes me being an idiot)
7. Final treatment of wiring harness at fuse box. Need main fuse relay holder that's not broken. Spence may have one.
8. Mount ECU properly. I didn't realize it goes in upside down in an E28. Gotta figure out how to make that work.
9. Drop fuel tank; replace with a refurbished tank I'm getting from Spence.
10. Install new fuel pump(s). Not decided to go with the Walbro solution or just replace the 2 piece system.
11. Install B35 air filter housing.
12. Dyno + tune. May end up moving to a MAF/War Chip, but I'm going to wait to see what Carb Connection suggests.
13. Rebuild exhaust.
14. Hook up power to E34 Sport Seats heat.
15. Get a e-brake boot made that matches/I'm happy with.
16. Euro bumper conversion.
17. Fix rust bubble that's appearing at left-lower rear window.

This project has only one more major phase to it: Break the engine in and then get it on the dyno to both baseline it against the B34 and to tune it. Everything else on the list is either minutia or really not about the engine swap. This thread will remain focused on just the B35 related things.

My trip to 5erWest will give me enough miles to have broken it in, so the dyno session will be scheduled for the week after next.

[kzolee]

[*]Have beer.

There's no confirmation on that.

You have missed the most important point on Your list. Why are You disappointed then?

Anyway, congrats on that job, that's one of the sexiest M30 engines on the planet.

[demetk]

Interesting... For clarification sake, are you running M1.3 on B35's or B34's..? Also, are your TPS' from a B34/M1.0 or B35/M1.3..? (I am using the TPS that was in the e32 that the rest of my conversion parts came from)

And as far as the "idle dipping problem"... I really don't consider it a problem because it is very slight when it happens. Maybe I'm more used to it now than when I first did the conversion, but I'm all ears if there's something I can do to prevent it...

All the cars are 5-speeds. The 89 535 has a b35 turbo setup and is running a converted manual TPS. The 95 530 has a b35 swap and is running the original auto TPS. And the 88 535 has the original b34 with the M1.3 swap and is running the original manual TPS. All exhibit no dipping idle symptoms. The turbo has the best idle transition from the other two with idle speed returning after a rev in about a second or two. The e28 has the second best and with probably the more normal idle transition. The 95 530 is a more abrupt to idle speed but that's only because I have yet to let the ecu know the ac compressor is turning on.

Maybe you guys that are experiencing idle dipping can comment on the following settings on your cars.

1. Your baseline throttle plate gap
2. At what distance from closed throttle does your idle signal activation happen.

Is it possible that an ICV can be slow to respond to control signals from the ECU?

cheers.

[528KC]

Wow. I just bought a b34 for super cheap and plan on building it back up, more for experience than anything else, and this thread has been a great read. It only took me two whole work days to get through it. lol. But im sure I will be revisiting this thread over and over through the months I'm already planning for it to take. Good job, I can only dream of building something this nice since my budget is incredibly low. Thanks for the inspiration and confidence though.

[tig]

Wow. I just bought a b34 for super cheap and plan on building it back up, more for experience than anything else, and this thread has been a great read. It only took me two whole work days to get through it. lol. But im sure I will be revisiting this thread over and over through the months I'm already planning for it to take. Good job, I can only dream of building something this nice since my budget is incredibly low. Thanks for the inspiration and confidence though.

Good luck! Start a thread. Take lots of pictures. Post them. Ask questions. We all have tons to learn. I'll do what I can to help.

Today I dropped by my mechanic to show off the engine. He had not seen anything but the head and block(s). I think he was a little surprised by the fit and finish .

We talked break-in and mixture. He believes I'm running way lean, but without seeing the wideband at load he doesn't know for sure. My assertions that it stays below 15 but never really dips into the 12s concerned him. He wants the car to nail 12.8 under load and any signs of running lean make him nervous. I find it odd that so many people post dyno charts of M30s (stock and otherwise) where the AFR is 13-15 and he is so nervous that damage is going to be done to the engine like this. But what do I know.

I then went by Carb Connection the tuning/dyno place here where I had Vlad with the B34 tested. I wanted to ask Alex, the main guy what he recommended. He was far less concerned after I showed him the wideband and described what I was seeing while driving. But he did say he had an opening tomorrow morning that just opened up. :-)

So, tomorrow 10am I'll be putting the car on the dyno and having Alex tune it. He knows he limited to the stock ECU at this point, but indicated he was confident he could nail it. He concurs that moving to a Miller MAF/War Chip later would be a good thing, but for now just ensuring the mixture is right is key.

The engine now has about 70 miles on it. No leaks, no weird noises. Just the annoying dip & spike. While there I upped the fuel-pressure to 5.5bar and on the drive home it showed a much greater propensity to stall when going to idle.

[athayer187]

The engine now has about 70 miles on it. No leaks, no weird noises. Just the annoying dip & spike. While there I upped the fuel-pressure to 5.5bar and on the drive home it showed a much greater propensity to stall when going to idle.

That sounds like what I saw too - sounds like you have the fuel pressure right. I agree it could be throttle plate or TPS related.

Sounds like you have a great motor put together - I'm in the process of putting a very similar animal together for my car (PB N31 cam and 806 pistons). Your thread makes me antsy!

[unt0uchable]

Nice work Charlie! Glad to see everything has come together nicely. I'll be waiting to hear how the dyno goes. Good luck!

[tn535i]

On the idle thing. What happens if you unplug the TPS? Does it still idle or dip. I find that unplugging the TPS is a good diagnostic for base throttle setting. If warm it should actually rev up a couple hundred rpm with the TPS idle input off (unplugged). If not the base throttle position is too far closed and you need to crack it open a little. Never mind measuring the darn thing it's too much trouble. Doing this is better and easier, trust me and you can play with it till you get it to act like you want. Start by just adjusting the T/B so that it revs up a little on a warm engine with the idle control off. The valve will have the right amount of range to control it from cold to warm.

I'm thinking it might be too far shut and when you come off throttle and the TPS closes the ICV also goes fully closed trying to slow the idle down. Then the revs finally fall but fall too much becasue the throttle is too far closed and the ICV is closed shut. Now it has to wake up again and open the ICV to maintain idle speed. Another clue would be if you get a jerky on/off idle transition at speed in higher gears. I hat that and clear indication T/B to far closed if so. If the T/B is too far open it will come down to idle much more slowly after reving it up, maybe even like it doesn't want to slow down all the way since now the ICV needs to be fully closed. It closes but can't really close enough.

If you start making fine tuning to the T/B you'll begin to see what I'm talking about. Of course every time you change the T/B position you must readjust the TPS. Also sometimes they idle better and smoother if you use the AFM bypass to force it to the rich side at idle. Just enough to stop it from dithering but no more. This might also help with tip in on the throttle.

And maybe some of your loping is the new cam. Big cams do that IME but I'm also better that after a few miles you need to go back through the valve lash again.

[tig]

This morning I went to Carb Connection in Kirkland, WA to have Alex, the owner, take a look at the engine under load and advise.

Summary:

The engine is basically perfect for having a stock 179 chip and AFM. It put down 195 rwhp / 216 rwtrq. It needs a little advance in timing and will likely easily break 200 rwhp once it loosens up a little and I can advance the timing (likely with a Miller War chip).

We started conservatively with 6-7 runs at partial throttle to about 4k RPM with 10% load on the dyno. We then went full throttle and did progressive runs up to 6000rpm/redline. Alex was checking for detonation or other issues and saw none. Silky smooth.

Here's a video of the tail end of this testing:


We then did 4 runs under max throttle, in 4th gear, to 5500 rpm. The engine just sings. As you can see from the curves below there's some lumpiness which will smoothen out with a tune (previously with the B34 the 3rd gear runs were smoother too), but the torque curve is sexy flat. The AFR is MUCH better than on the B34 and seeing this gives me tons of confidence that the 24lbs injectors are doing their job and that I'm not running lean (my machinist had scared me senseless about this).

Here's a video of the 3rd run, showing just the tach and wideband, this was the best run:


Here's the final run from a different perspective :-):


Here's the graph, which includes the two best runs done with the B34. Note that it was about 82 degrees today vs. 70 when I did the previous run (and those B34 runs were in 3rd gear).

(click for higher resolution)

Needless to say, I'm giddy with these results. Paul Burke told me to expect this M30B35 would be good for 30-40 hp over the B34. Knowing that ALL purveyors of performance engine stuff exaggerate my hopes were set at just exceeding 200hp. If it exceeded 210 it would be icing on the cake. Once I can tune the advance with something like a War chip, I should easily break 200. And, of course, what's really important is the torque .

Even better, by putting the car on the dyno and pushing it relatively hard, with someone who knows their shit there to advise, my confidence in the build has gone way up .

[tig]

I dove into trying to figure out the dip & spike & sometimes stall problem.

The tips above about TPS and the throttle made me remember that I tore down and completely re-assembled my throttle after having it powder coated. I realized that I likely didn't get something right. I took it off to check and compare it to the other throttle body I have.

The first thing I noticed was the gasket was wet. This surprised me. There's not supposed to be a lot of gas in there, and it sure seems like gas. The inside of the intake boot is pretty dry, but there was a smidgen of wetness to it.





Is this something I should be concerned about? In any-case, when I reassembled it I coated the gasket with some copper gasket sealant spray just to ensure it doesn't start leaking.

I also realized the inside of the TB was rough from the media blasting. The throttle plate definitely stuck when closed. I took some light emery paper and shined both the inside of the TB and the edges of the throttle plate. I cleaned it with carb cleaner to ensure not grit was left over. Then I adjusted the set screw on the side of the throttle that determines how far the plate closes so that it's JUST a smidgen away from completely closed.

After installation I adjusted the throttle cable & TPS using the "I can hear the click" method. Off for a drive to see if it helped...

[12valves]

That's a pretty nice dyno result. And I bet tuning could put a bigger bump in the middle of that torque curve.

[wkohler]

So, how many miles is the break-in process?

[tig]

So, how many miles is the break-in process?

Seems like everyone has an opinion on this. My machinist says 1000 miles. My tune guy says its already broken in.

I'm going to split it down the middle. The key is to avoid long periods of constant rpm. Lots of hard pulls with subsequent deceleration with compression.

[unt0uchable]

...After installation I adjusted the throttle cable & TPS using the "I can hear the click" method. Off for a drive to see if it helped...

How'd it drive after all of this?

Those dyno results have got to be a nice number to see. Nearly 200whp from a very nice b35.

Hope you get that drop and spike figured out. That things sounds like a kitten on the dyno man! Awesome work. Just pure awesome.

[tig]

I just got back from 5erWest. Good news; bad news...

Good news: The engine performed beautifully! It now has just shy of 1000 miles on it and is officially broken in. It pulls incredibly hard, sounds great, and just generally operates as perfect as it can without being tuned.


Bad news: On the back-side of Mount Hood we stopped for a break and I figured it would be smart to check under the car...just in case. I'm glad I did and I'm sad I did.... there was a quarter sized spot of oil. Uh, oh.

After we stopped at the Full Sail Brewery in Hood River for lunch looked closer and there was a little oil on the bottom of the bell-housing and some splatter back on the exhaust support at the back of the tranny. Not a good sign.

I just put it up on the lift and looked around.


Ugh. However, if you look closely at this pic, you'll see some moisture up where that permatex is by the oil pan joint at the bell-housing...


Based on what I can see without unbolting anything I'm very (perhaps delusional) hopeful that it's coming from the oil pan gasket at the right-rear.

I scraped off the excess permatex and cleaned that area. Tomorrow after driving to work I'll look again.


Please say a prayer for me tonight that this is it, and that it's not my rear seal or seal-cover gasket. I really, really, really do not want to take it all apart again

In other news: Those plugs I bought at ACE for the reference sensor holes in the bell-housing? Obviously not a workable solution as one is probably on Mt. Hood right now.

[Kyle in NO]

I hate oil leaks!

[tn535i]

Why does it appear to be a gap between the stiffener and the trans bell housing? Can I see the flywheel ring gear? Is the stiffener for a different trans than that one or is the stiffener missing?

For the plug I think an aluminum or nylon piece like a mushroom held in by a bolt and washer would do the trick but if there is a gap between the stiffener and bell housing anyway a plug won't matter much to seal it up.

[tig]

Not sure what you mean by stiffener.

From what I understand you are supposed to be able to see the flywheel teeth; these things are never fully sealed up.

[ahab]

Those plugs I bought at ACE for the reference sensor holes in the bell-housing? Obviously not a workable solution as one is probably on Mt. Hood right now.

Stick with BMW parts and stay out of the hardware store. Try caliper guide pin dust covers. As for the oil pan leak (or hope of), I'd recommend Permatex Aviation Form-A-Gasket #3 for all paper gaskets. That orange crap is for 'murrican iron and gas station repair bays. I would have offered my unsolicited advice sooner but once we got over 3 pages I was out.

[Ron535i]

In other news: Those plugs I bought at ACE for the reference sensor holes in the bell-housing? Obviously not a workable solution as one is probably on Mt. Hood right now.

Try BMW part #21111225047 (realOEM, > Manual Transmission => Individual transmission parts #19, Blind Plug)

I can be a little anul too and I bought these when I did my m1.3 conversion. Very inexpensive.