Engine cutting out

[Amskeptic]

I like the idea of using hot wire AMM instead..cant be that difficult...whats the out put signal look like? how is it different from the
flipper ?

Did you read this: http://www.gowesty.com/library_article.php?id=805

And follow up with this: http://www.gowesty.com/library_article.php?id=1532

I think those should answer your questions.

Than follow it up with this one: http://www.splitsec.com/technotes/AFM_t ... ersion.pdf
Split Second are the makers of the AFM replacement GoWesty was/is offering.
In a nutshell, the MAF sensor doesn't have the range of output (0-5V) that our ancient AFMs do (0-9V-ish), not to mention a different response curve. The Split Second solution is a digital one, and while I'm all for microprocessors where they make sense, I think in this case an analog solution would give smoother results. I only wish I had the analog background to design the circuit.

I am not buying some of the "ad-speak" in this conversion. Right off the bat, they are talking about "air flow restriction" with photographs of "sharp edges" and whatnot. But . . . we are so far upstream of the Big Air Restrictor aka throttle plate, that no one can say that the air flow meter is restricting the engine's breathing. Hawgwash.

Next, when I read of "be sure to keep your oiled mesh air filter clean" because it could "affect the sensor wire calibration", I have to ask, "why have an oil mesh air filter when the stock paper filter is a known superior filtration device?"

Then I read that the analog signal of the AFM seems to fill the blanks better than a digital trying to play catch-up with its own fill-in-the-blank programming yet the concluding paragraph just has to declare that it expects this digital hot wire system is going to improve driveability. No it isn't. It is going to luckily maybe match the original. Period.

The calibration table is where I am most out of my league. I never did find a "recipe" with all of my exhaustive testing of a non 0-2 fuel injection system. I had a tailpipe sensor, not a bung further up the exhaust stream. But I did replicate over and over the fact that a hot pissed-off air-cooled 2.0 preferred a richer mixture and offered better fuel economy. If I were to offer a hill-billy rationale, I could feel the responsiveness of the engine under my right foot. Any time that the accelerator did not translate in verifiable work (acceleration), I ran hotter. There is some beautiful little point where the mixture is converted into work more effectively, and this allowed lower CHTs. If I was too lean, all hell would break loose as I filled the cylinders more but less work was accomplished > heat heat heat. I will re-verify this spring when I do my much-anticipated EGR/CHT relationship test on my Florida itinerary with the BobD.
Currently, my best understanding of the mixture claims that 11.2 under full acceleration at 55 mph leaning to 11.6 or so by 70 mph with a sharp lean to 13.5 or so at steady cruise to a fuel shut-off 22 or so under high speed throttle-off, turning back on to 16 at lower rpms, seems to be the sweet spot.

Airkooledchris and I did some testing with his 0-2 sensored engine, and we had to conclude that there are secret moments where somehow the engine is happy? with stochiometric 14.7 ?? because it somehow knows that the (if installed) catalytic converter is the princess who must be kept happy, yet it would seem too lean for the head temps? Where are we at with that, Chris?
Colin

I was there when CDs promised "brilliance" in sound recording, but we all knew that "0"s and "1"s were taking away ambience that only analog could provide.

[satchmo]

Then follow it up with this one: http://www.splitsec.com/technotes/AFM_t ... ersion.pdf
Split Second are the makers of the AFM replacement GoWesty was/is offering.
In a nutshell, the MAF sensor doesn't have the range of output (0-5V) that our ancient AFMs do (0-9V-ish), not to mention a different response curve. The Split Second solution is a digital one, and while I'm all for microprocessors where they make sense, I think in this case an analog solution would give smoother results. I only wish I had the analog background to design the circuit.

Interesting. I thought we had the whole digital-to-analog thing all figured out years ago when we started recording and playing music on something called Compact Discs. But like I said before, I'm just a simple cave man.

Tim

PS: Just saw Colin's CD reference above after I submitted my reply.

[SlowLane]

Than follow it up with this one: http://www.splitsec.com/technotes/AFM_t ... ersion.pdf
Split Second are the makers of the AFM replacement GoWesty was/is offering.
In a nutshell, the MAF sensor doesn't have the range of output (0-5V) that our ancient AFMs do (0-9V-ish), not to mention a different response curve. The Split Second solution is a digital one, and while I'm all for microprocessors where they make sense, I think in this case an analog solution would give smoother results. I only wish I had the analog background to design the circuit.

I am not buying some of the "ad-speak" in this conversion. Right off the bat, they are talking about "air flow restriction" with photographs of "sharp edges" and whatnot. But . . . we are so far upstream of the Big Air Restrictor aka throttle plate, that no one can say that the air flow meter is restricting the engine's breathing. Hawgwash.

Next, when I read of "be sure to keep your oiled mesh air filter clean" because it could "affect the sensor wire calibration", I have to ask, "why have an oil mesh air filter when the stock paper filter is a known superior filtration device?"

Yeahyeahyeah. Keep in mind that Split Second's target market appears to be the BMW crowd. 'nuff sed?

[SlowLane]

Interesting. I thought we had the whole digital-to-analog thing all figured out years ago when we started recording and playing music on something called Compact Discs.

Ultimately, all signals are analog, even in the the fastest digital circuits. Engineers who cut their teeth on digital (myself included), often lose sight of that.

[Amskeptic]

Interesting. I thought we had the whole digital-to-analog thing all figured out years ago when we started recording and playing music on something called Compact Discs.

Ultimately, all signals are analog, even in the the fastest digital circuits. Engineers who cut their teeth on digital (myself included), often lose sight of that.

Ya young pup . . .
ColinVacuumTubeRadioWarmUpCertified

[khargis]

what happened satchmo? this is exactly what my bus is doing and it is raining but i am not in point reyes, i am in good old reddin'!

[Amskeptic]

what happened satchmo? this is exactly what my bus is doing and it is raining but i am not in point reyes, i am in good old reddin'!

We are not going to short-circuit your own required diagnostics here, by telling you that Tim happened to fix his own cutting out by swapping a different ECU into his bus as written about back on Page 2 or 3 of this thread, are we? He had some worn tracks.
Colin

[khargis]

hello, 4-6 clicks to the left or right? Is it Left(lean) and right(rich)? Thanks, Kris

increasing episodes of cutting out
checked the distributor,
the points,
the plug wires,
the AFM connector,
put in a new fuel pump and filter.
Is there something else I should check?

Smoothly increasing rate of episodes might suggest a vacuum hose split that opens up a little more after the engine does a major shake. As SlowLane mentioned, start with a comprehensive check of vacuum integrity. Did you glue your valve cover gaskets to the valve covers? If not, check them for proper positioning.

If this symptom is temperature related (like it never screws up when engine is still cool), consider things like ignition coil resistance, temp sensor 2 resistance. If everything checks out, lean the mixture at the black cog 4-6 clicks, we want to either inflame or ameliorate symptom. If inflamed, go rich a bit and see if that helps. If it improves (my guess), you have a choice.
A) lean it by means of wiper?
B) lean by means of black cog?

Use A if idle is saying it is a little rich at full operating temp.
Use B if idle is already close to too lean.
Colin

[satchmo]

A quick review here (viewtopic.php?f=50&t=7761) should help.

Tim

[khargis]

thanks tim.

[Amskeptic]

thanks tim.

Well, the Cause was pretty badly worn tracks. We drilled the wiper track board mounting holes oblong and found a terribly skinny little place for the wiper to pass through, and it now runs acceptably. The Solution is a new/used/"rebuilt" AFM.
Colin

[Jivermo]

What is the black wiper blade contact surface made of-does anyone know? I'm guessing that it is an electrically conductive coating. Has anyone looked into any sort of product that might be used to renew the contact surface when it wears through. We adjusted my board when Colin was here by sliding it back a tiny bit. I don't quite understand how the whole thing works...it is quite the gizmo.

[Amskeptic]

What is the black wiper blade contact surface made of-does anyone know? I'm guessing that it is an electrically conductive coating. Has anyone looked into any sort of product that might be used to renew the contact surface when it wears through. We adjusted my board when Colin was here by sliding it back a tiny bit. I don't quite understand how the whole thing works...it is quite the gizmo.

Electrically conductive semi-graphite-impregnated resinyblobablicka, and it is painfully thin.

Don't understand how what works? The whole thing? It is a simple potentiometer like a rheostat on your dining room light switch.
More accelerator pedal blows the flap open while the wiper attached to the flap shaft moves towards less resistance. The signal is interpreted to provide a longer fuel spray (in milliseconds, by the way) to the injectors. Simple! Elegant!
Colin

[khargis]

hey there folks. The bus 'bad danger' has been running like a top, until yesterday... About a month or so ago, i was having starter problems, I bought a rebuilt Bosch and had a friend mechanic put in in while i was out of town, along with a new bushing. Upon my return (prior to Colin and I's visit by about 3 weeks) the bus started fine (ran shitty until Colin and I worked on it, but it started) yesterday I was driving about 15mph and I could not accelerate, so I pulled over and turned of the van, thinking a hose came off. Hoses checked out fine, accelerator cable fine, so I go to start the bus and the starter spun mindlessly even when I turned the key off, i had to get under and rap on the starter to get it to stop. I push started and got home. I tried to start and nothing, not even my aux and oil light came on, so I got under the bus and used my screwdriver to cross the 2 big bolts on the solenoid and the starter began to whirl and then I did the same with the "battery" terminal to the ignition switch terminal on solenoid, the bus acted like it was turning over. This morning I got under and cleaned connections on solenoid, cleaned battery posts, made sure stuff was tight, checked fuses, did a dance and turned the key and.... the bus acted like it wanted to start and everything stopped, no oil or aux lights when key is turned, no nothing, battery is good. I had to cross the 2 big bolts to get the oil and aux lights to come back on. So bummed! Any thoughts? (I talked to the guy that put the starter in and he said that it may have failed and I know I have a 2 year warranty) Could it be the ignition switch? Thanks people, Kris

[Amskeptic]

If the lights go out upon a big demand, like the starter, then a big connection is likely the culprit. It is sort of an instant oxidation that blocks electrical flow.
Scrape the battery posts shiny. Scrape the inside rings of the terminals that fit on the posts. Loosen the bolts on the terminals so that you know they will go down the battery posts fully, then tighten firmly but not nutso.
Do the same clean shiny at the starter post (NEGATIVE CABLE OFF THE BATTERY) where the battery positive cable goes, and every single wire that joins it there.

There is a big red/white wire on the starter post that feeds the fuse box and all electrical consumers up front. Make sure it is next to the battery cable.
Colin