Open Heart Surgery

[Swiss 2002Tii]

57 minutes ago, PaulTWinterton said:

Seems overly rich to my mind.  I'm around 10.5-11 at idle.

Thanks for the encouragement Paul.  This time around I'm making small, incremental steps.

 

Before I changed out the KF pump I was getting a miserable 16 miles to the gallon.  I am just working through my first tankful since the change.  It seems better, but we'll see.  I am really winding it up to see the POT and WOT AFR readings, so not looking for economy at this point.

 

After a few more tweaks I'll fill it up and then do some "normal" driving and see if it has improved.

[Conserv]

On 4/6/2019 at 7:37 PM, PaulTWinterton said:

 

Lastly, I thought all E12 heads in 72 did not have a fuel pump plate, just a blank.  Learn something new everyday.

 

Good work.  

 

 

 

A Note on E12 Heads

E12 heads, like 121 heads before them, came from the factory in both a drilled (carbed) form and an un-drilled (tii) form — originally.  My ‘73 tii (VIN 2762757, October 19, 1972) has an un-drilled E12 (dated August 1972, if I recall). And I am accustomed to seeing un-drilled E12 heads on tii’s from late in the 1972 model year onward. I purchased a drilled backup E12 head (dated July 1972), however, because — with quality heads becoming a rarity — I am more concerned with head thickness and overall condition than with pedigree. (And, I admit, I would probably have the fuel pump boss holes filled if the head was placed in service on my tii.)

 

I assumed this backup head served originally on a carbed tii, but if your car’s head is unambiguously original to your engine, then I suppose my backup head could have theoretically served originally on a tii.

 

I do not know the state of “replacement era” E12 heads: (a.) drilled, (b.) un-drilled, or (c.) both. I suspect the answer might be (c.) if you view the overall “replacement era” as ca. 1976 through 198? (or is that 199?). (The E12 head, designed and named for the 4-cylinder versions of the e12 series, was introduced in early 1972 and used on ‘02’s through June 1976, the end of 2002 production. The E21 head, designed and named for the 4-cylinder versions of the e21 series, appeared only on 49-state 1976 2002’s.) But at some point, you simply accepted whatever BMW might be able to provide.

 

Back to Business

I stopped following this thread when things got busy for me. Oops. Great, detailed thread! I’m reading with great interest now.

 

Are the multiple sensor failures possibly related to the bung’s location (apart from the depth issue that Ted mentions)? Are there different viewpoints on the bung location? Obviously, I’m finding a wide-band installation increasingly attractive ? and looking at this issue.

 

Thanks and best regards,

 

Steve

 

 

 

Edited May 2, 2019 by Conserv

[PaulTWinterton]

38 minutes ago, Conserv said:

Are there different viewpoints on the bung location?

 

I'm a year into AFR use and have had uninterrupted service with my WB setup using the Bosch LSU4.2 sensor.

 

http://www.wide-band.com/product-p/wb_d2n.htm

 

Reading and listening to professionals I situated my bung as far back as possible to (more) accurately read collected gases and for easy access.

 

[Swiss 2002Tii]

7 minutes ago, Conserv said:

Are the multiple sensor failures possibly related to the bung’s location (apart from the depth issue that Ted mentions)? Are there different viewpoints on the bung location? Obviously, I’m finding a wide-band installation increasingly attractive ? and looking at this issue.

Welcome back Steve,

Thanks for the configuration detail on the E12 head.  I could not testify to the originality of the E12 head on my engine.  It is stamped '72, but there are a number of other details on the car that point to contributions from a '74 for example, that I would guess that it was replaced.  Cleaned up just fine and my valves are ticking along, so I just drive! ?

 

Regarding the sensors, I think my first one failed from a mechanical shock, as it was mounted on the tailpipe and dropped off.

The second one is back in operation.  It's still a little quirky, but working most of the time.  The Innovate tech suggested it was starved for current for the warm-up, and that is likely true.  I cut off the cigarette plug and have it jumpered in with the alligator clips but the wires are probably too thin. 

I have wired up a permanent beefier connection but haven't had a chance to mount it yet. I made sure it had a good solid connection and its behavior improved.  I believe that it will work better when I can get it wired in next week.  I thought I would wire it to my fuel pump line at connector #31, as it would then only be powered when the fuel pump is running.  I have installed heavy gauge wire all the way to the pump, but as I'm writing this, I'm thinking of my months-long fuel pump current starvation adventure...?  

I think I'll go with the radio circuit! ?

 

Anyone who has read Ted's comment about the original wiring harness for the fuel pump being insufficient to support the current draw on the pump and doubted the significance, trust me - you want to fatten up that wire all the way to the battery! ?

It's a separate harness that runs along the wall along the driver's side under the plastic sill, along under the rear seat, into the trunk and along the spare well to the tank.  Easy upgrade. Replace both +12v and Ground at the pump with at least AWG 14 or AWG 12 (3 sq. mm in EU).

 

Per Innovate, the sensor should be at least 24 inches from the exhaust port, that's about 4 inches beyond where the down pipes join.  Their sensor needs to be recessed from direct exposure to the exhaust flow, so they supply the 1" bung mount. 

 

[Conserv]

Thank you, Gentlemen!

 

Best regards,

 

Steve

 

[Einspritz]

I'm working on a Tome, so until then, please stop obsessing about your idle AFR!

[ray_]

I'd be concerned if I were seeing leaner than 13.3 under load with your foot on the floor at 4000rpm's and up.

 

I'd also have a concern that you're contaminating oil at richer than maybe 11.5 at idle...

 

Good that it's running well!

 

Cheers,

[Swiss 2002Tii]

8 hours ago, ray_ said:

I'd be concerned if I were seeing leaner than 13.3 under load with your foot on the floor at 4000rpm's and up.

 

I'd also have a concern that you're contaminating oil at richer than maybe 11.5 at idle...

Good advice... I'm on it next week... after they wash the salt off the roads... Snow forecast for Sunday!!! 

Not so much where I am at 450 meters, but they got a meter of snow above 800 meters a week ago, and it looks to do the same on Sunday!

 

I have to work on narrowing the mixture band.  As you say I'm too rich at idle/POT, too lean at WOT.

[Swiss 2002Tii]

So how to narrow the  AFR band over range of throttle travel?

This is where my practice of grabbing interesting details and posting them to a Word Doc so I can find the info again actually worked as planned.  I cannot find through Search where I grabbed this from, I thought it was from my thread (long thread, simple solution):

But I don't find it there. It might have been WAS part of a KF/WUR thread Paul W. was running at that same time... FOUND IT!?  Great thread!

Anyway, I thought this might apply to narrowing the range of fuel over the throttle position arc from idle/POT/WOT.  dlacey's original post had this cool video graphic of this geometric model.

 

 

 

dlacey    39

•  

March 26

Effect of the length of the 85mm rod

I took a look at the linkage..and will use a crankshaft analogy...the real situation quite complex as the arcs moved by the throttle spindle and the kugel spindle are in different planes...i guess a serious mathematician could take that into account..

The Throttle butterfly ball/pivot (that the rod clips on to) starts (closed throttle) at~10 ATDC (TDC is 3 o'clock on the GIF wheel below, ignore the red/green/blue) and as throttle is opened goes to 90 degrees ATDC and at full throttle is about 110 degrees ATDC... that means the linear motion of the rod (related to the angular opening of throttle) starts low, rises to a max and then starts to decrease again at WOT (in the GIF its the crankpin moving from ~4 o'clock to 7 o'clock).

The Kugel throttle position lever ball/pivot goes from something like 190 degrees ATDC closed throttle to 270Degrees ATDC at WOT. (in the GIF from just after 9 o'clock through to exactly 12 o'clock). That means that every, say 1mm, movement of the rod is having a decreasing rotational degrees effect on the pump lever as you move towards WOT.

So, it seems that the linear variations DO NOT cancel out, as the two pivot points do not follow equal/opposite arcs relative to the rod direction.

If the rod were shorter and all other Tii setup procedures were followed, the throttle butterfly ball pivot would start closer to TDC, (closer to 3'o'clock), meaning there would be less linear motion (per degree of throttle angle)....that would weaken the part-throttle mixture as the Kugel lever will simply move less... 

If the rod were longer, then the throttle ball pivot would be further from TDC, meaning more linear motion per degree of throttle angle in the part-throttle period, meaning more kugel lever movement early-on...meaning richer earlier.

hope this makes some sense...

I am gonna experiment at the weekend...

 

So after I go through all of the standard adjustments WUR enrichment lever travel @ 2.6mm, D-cam adjustment, air mixture adjustment, etc...  If I still have too broad an AFR band, 

I would give this a try.

 

Edited May 3, 2019 by Swiss 2002Tii
additional info

[Einspritz]

I was writing a Tome and addressing Paul's rant about gas mileage, but felt with all the conjecture it be best to put bullet points for Tom's situation.

 

On 5/2/2019 at 8:35 AM, Swiss 2002Tii said:

I made three incremental 1/8 turns CW on the air mixture screw, driving and observing AFR and response between each 1/8 turn adjustment

Warm idle: dialed down to 900 rpm, AFR likes to stay at a steady 8.6

Low partial open throttle: @ 2000-3500 rpms, AFR 9.6 -11

High partial open throttle: @ 3500-4500 rpm, AFR 12.0-12.8

Wide open throttle: @ 4000 -5500 rpm, AFR 13.0-15.0, only exceeded 15.0 as a spike on engine braking, coming off of throttle (occasionally)

When running at a constant rpm without load, AFR would settle at 9.0-9.6 at pretty much any rpm.

 

Get back to your previous pump setting to get the WOT to 12.8-13.0 AFR., 12.8 is the stoichiometric where the most poser will take place.

THEN fiddle with the "D" cam to get your partial throttle AFR to come into play. The technical stoichmetric value for the best fuel economy is 15.4 AFR, but I wouldn't go that lean.

 

The thing about specifying an AFR for partial throttle is that it is dependent on several factors, the head, the CR, the timing, if you have an early or late pump cam, valve adjustment, and on and on.....So what is good for a '74 Tii is not the same for a '72.

 

The BEST AFR for partial throttle is the one that is just richer than when the engine detonates, but I can't tell you what that point is. So, then, shoot for ~2.0-4.0% CO which is 13.00-13.77 AFR. You will know it when you drive it.

 

The AFR will spike lean when you take your foot off the throttle, and that is normal, but it should stabilize "rock steady" back to your partial throttle or idle mixture setting.

 

The idle mixture setting can be from 2% CO / 13.77AFR to a maximum of 5% / 12.64 AFR; whatever will give you a smooth idle and smooth transition from idle to increased RPM with no "hitches".

 

In summary, your WOT is too lean, and your idle and partials are too rich.

 

As Tom and I have discussed, here is where having an output graph is key to validating the pump is correct, as everything else follows. the visual of seeing the WOT, the P2 and P3 as well as the idle graphs help you to understand.

 

 

 

 

[Swiss 2002Tii]

Thanks Ted.  I've got my homework for next week - after snow and travel!

[Swiss 2002Tii]

I had a chance for some good tuning runs, and my AFR meter actually cooperated a couple of minutes out of several hours of driving! ?

I dialed the mixture screw back about 3/8 turn to where I started, set the idle @ 900.

I got really strong performance, but back to a rich idle at AFR 8.6-9.4, and POT around 10.6-11.0, WOT at around 12.6-12.9.

I turned a couple 2 x 1/8 CW, gained some RPMs, so I reset back to 900 rpm again, and went driving.  Quite good performance, quickly spinning up to 5000 rpm, idle AFR around 9.6-10.0, POT around 11.2-12.1, WOT at 13.2-13.6.

It felt like I had done as much as I could with the mixture screw, and didn't have the range.  I locked the KF lever and moved the D-cam slightly to the right, perhaps 1.0-1.5mm away from the hole to move the AFR range leaner.

I dialed in one more 1/8th CW and got to idle 10.0-10.2, POT around 11.8-12.4, and WOT at 13.6-14.1.  I'm getting just a "catch" as I accelerate in third gear through 3000 rpm.  Run-up in 1st and 2nd gears is pretty much straight ramp up, just the catch in third.  

I think I'll dial it back 1/8th and just drive and observe for a while. 

Might as well, as my AFR meter is now almost useless.  Of the last four hours I've driven, I have only had a few seconds of stable readings.  Mostly error codes and wildly meaningless numbers.  I am going to write for a warranty claim on the sensor.

 

All in all, it's running really well, and I'm driving it as my daily driver whenever the weather permits.  It's just great having a quick little run-around for errands in town!

 

My throttle body support bracket had broken at the TB mounting screws, so I gave it to a local metal shop and they seriously beefed up the head of the bracket! (great to find a local shop!)  I may have to cut it back some, but it sure is solid!

 

At some point soon I will have to pull the air filter and maybe a runner to swap out the warm-up regulator (and of course, drain my coolant again ?).  Unfortunately my liquid metal patch job has a (very) slight leak.  I can't see, but can feel that the liquid metal has lifted at the edges.  Just a drop now and then, but if it failed altogether, I could lose coolant pretty quickly.

 

 

 

[ray_]

FWIW I dumped my Innovate years ago because it was being wonky. Though Daron got it to mostly behave. I'm running and analog AEM gauge now.

 

Looks like you are making good progress!!

 

Cheers,

[chargin]

On 5/2/2019 at 12:51 PM, Swiss 2002Tii said:

 

Anyone who has read Ted's comment about the original wiring harness for the fuel pump being insufficient to support the current draw on the pump and doubted the significance, trust me - you want to fatten up that wire all the way to the battery! ?

It's a separate harness that runs along the wall along the driver's side under the plastic sill, along under the rear seat, into the trunk and along the spare well to the tank.  Easy upgrade. Replace both +12v and Ground at the pump with at least AWG 14 or AWG 12 (3 sq. mm in EU).

 

Tii Truth, I ended up calling a flatbed when I singed the connectors and lost pump power. Now the BMW OEM trigger wire which routes through a Inertia Switch only powers a Relay in the trunk, That's al 12 Gauge wire!

 

My AFR looks to be updated from the one pictured in the Group Buy

 

 

and my Bung location

 

 

 

Edited May 20, 2019 by chargin

[irdave]

Can we get a pic of the inside of the tuna can?