DWELL meter

[Bitsyncmaster]

I've expended my RD funds for a while, doing my environmental oven and the new smaller lambda ECU. But I though of another project while working on the lambda. Since it's getting hard to find dwell meters anymore, I though of building a new dwell meter.

It would contain an LCD displaying:

INSTANT DWELL
AVERAGE DWELL
MINIMUM DWELL
MAXIMUM DWELL

It would have a reset button to reset the average, min and max readings. It would power by an alligator clips to the battery jump block and engine ground. Of course a banana jack for the dwell input signal. Using car power would let me backlight the LCD and make the unit smaller.

Remind me later in the year about this if anyone is interested. Or if someone else wants to do one you can use my suggestions.

[FABombjoy]

I would think one of those >$30 pocket oscilloscopes would be work well. They can read out duty cycle which is the true measurement anyway.
For example:
https://www.aliexpress.us/item/3256805458469353.html

Loads of additional diagnostic uses. I picked one up for the garage and its amazing for the price point.
For most purposes it beats dragging my big scope into the garage.

[Bitsyncmaster]

I would think one of those >$30 pocket oscilloscopes would be work well. They can read out duty cycle which is the true measurement anyway.
For example:
https://www.aliexpress.us/item/3256805458469353.html

Loads of additional diagnostic uses. I picked one up for the garage and its amazing for the price point.
For most purposes it beats dragging my big scope into the garage.

Agreed. You just have to remember that dwell times the negative pulse so if your scope reads duty cycle it uses the positive pulse for the resulting values. You also have to multiply the duty cycle value by 0.9 to convert it to 4 cylinder dwell numbers.

[David T]

An analog (mechanical meter) type dwell meter is easier to read than a digital display, especially when it is not a steady reading. There are plenty of them around cheap on the Web. I doubt there would be much interest in your project. Once you set the duty cycle it only changes if there is a change in the parts, a vacuum leak, a bad O2 sensor, etc. The fix is not to adjust the duty cycle, it is to replace the parts. Kind of like the torsion bars. Once properly adjusted you never should have to adjust them again, just replace the weak strut.

[FABombjoy]

Disagree.
I datalogged this thing extensively while trying to make K-jet turbo work well (it doesn't)
The Lambda box just ping-pongs between two values. It's an "all P" PID controller.

It would be beyond trivial to make a digital display with high/low/calculated mid point. Or call out certain modes (warm up, full throttle enrichment).

I can see the value in a plug & play device that just display the relevant data in an easy to read method. The scope I mentioned would take some know how.

[r00b]

What would be cool is a delorean clock that had multiple functions including dwell meter. Then you could just switch to the meter whenever you needed.

[Bitsyncmaster]

What would be cool is a delorean clock that had multiple functions including dwell meter. Then you could just switch to the meter whenever you needed.

Cool idea. One guy did already do that but low interest made him stop selling.

My new small lambda ECU can have a remote LED attached. It shows solid when dwell is within 35 to 45 deg dwell, flashing outside that range. Will be off during warmup, disconnected sensor, WOT or dwell at the max or min value. My original ECU has that same function but the LED is mounted on the circuit board since there were no spare pins wired in the OEM harness.

[Emit]

Yes please. A nice simple (to read/understand) dwell meter would be very welcome - I'm looking at getting my car set up for the first time and analog dwell meters are not readily available where I am, and while I'll have to use a scope or a digital dwell meter (multimeter) there is a lot to set or read incorrectly.

it would be a great addition to the community that would enable people to have their cars running well, without having to resort to piles of text, and swinging gauges.

[Michael]

Yes please. A nice simple (to read/understand) dwell meter would be very welcome - I'm looking at getting my car set up for the first time and analog dwell meters are not readily available where I am, and while I'll have to use a scope or a digital dwell meter (multimeter) there is a lot to set or read incorrectly.

it would be a great addition to the community that would enable people to have their cars running well, without having to resort to piles of text, and swinging gauges.

Doesn't get any easier than to read an analog dwell meter not to mention there are dozens if not hundreds of old school meters on eBay right now all for under 100 bucks, most in the 20-30 dollar range.

[Emit]

Doesn't get any easier than to read an analog dwell meter not to mention there are dozens if not hundreds of old school meters on eBay right now all for under 100 bucks, most in the 20-30 dollar range.

True, they are easy to read but as I said, not everyone lives in the land of bucks ;) , and we need to push the envelope of these things, make parts and procedures simpler and more reliable.

This solution won't be for everyone, but I'd love to be able to glace at a gauge/light/meter and see my dwell is out - especially if it's part of another upgrade like the lambda computer.

[David T]

True, they are easy to read but as I said, not everyone lives in the land of bucks ;) , and we need to push the envelope of these things, make parts and procedures simpler and more reliable.

This solution won't be for everyone, but I'd love to be able to glace at a gauge/light/meter and see my dwell is out - especially if it's part of another upgrade like the lambda computer.

Anything Bytsyncmaster could make is going to cost you more than you can find a dwell meter for on E-Bay even if you include shipping (you would have to have him ship his too!). It would be neat to get it on the dash, even in the clock, but it really isn't necessary. As for "easy to read", an analog meter is much easier to read when you have a changing value, it is more intuitive to see the rate of change (which BTW is the 1st order derivative). A scope is also nice but takes a bit of skill to operate and read.

[Bitsyncmaster]

Anything Bytsyncmaster could make is going to cost you more than you can find a dwell meter for on E-Bay even if you include shipping (you would have to have him ship his too!). It would be neat to get it on the dash, even in the clock, but it really isn't necessary. As for "easy to read", an analog meter is much easier to read when you have a changing value, it is more intuitive to see the rate of change (which BTW is the 1st order derivative). A scope is also nice but takes a bit of skill to operate and read.

Yes it would cost a lot more than used Ebay dwell meters. Most of that cost would be due to a machined box and the LCD display.

Soon to come out is a "Mini-Lambda ECU". That will let you keep your original but would need you to connect the 7 or 8 wires. Most benefit is for customers overseas to save on shipping. It removes the OEM lambda ECU from the cubby which gives you more room and less heat in the cubby for a speaker and or audio amp.

[Michael]

True, they are easy to read but as I said, not everyone lives in the land of bucks ;) , and we need to push the envelope of these things, make parts and procedures simpler and more reliable.

This solution won't be for everyone, but I'd love to be able to glace at a gauge/light/meter and see my dwell is out - especially if it's part of another upgrade like the lambda computer.

If a 30 dollar dwell meter is a hard pill to swallow, check the prices on a fuel distributor. Besides, mixture is something most of us may check once a year, and set even less often. It's one of those things that really doesn't need constant monitoring especially to the point of adding a gauge to your dash.

I'm not throwing off on Dave's product or idea but I think you are looking for a problem to your solution.