Oxigen Sensor question

[Oldblueaccord]

Before I move anything in my tune, I'll check if there is a fuel economy improvement just by removing the lag due to the age of the old sensor.

In the mean time, it is only a nice before-after chart

I should let you test mine sometime there original with 315,000 miles on them. I pulled a 32 mpg with 87 octane and a few ounces of acetone.

What fuel octane do you use or do you have where you live?

I also wonder how much the stock Honda ECU samples the O2 sensors and how much they effect the fuel mix. I have thought about unhooking them and doing a mpg test to see.


wp

[Buzo]

I should let you test mine sometime there original with 315,000 miles on them. I pulled a 32 mpg with 87 octane and a few ounces of acetone.

What fuel octane do you use or do you have where you live?

I also wonder how much the stock Honda ECU samples the O2 sensors and how much they effect the fuel mix. I have thought about unhooking them and doing a mpg test to see.


wp

WOW 32 MPG! I would not move anything! Not sure about the octanes in our fuels, all I know is that we have only two options, one expensive and another less expensive, so I use the less expensive.

What is that acetone thing? Do you pour it in the tank with each refill?

[Oldblueaccord]

Well my car is stock fuel injection so to me 28-32 mpg is about average maybe a little high. The only two things that might help it is I have a K+N filter cone directly on the throttle body and newer RCeng. 250cc injectors. I have some wideband O2 checks and for the most part the cars runs very well with it being rich 12.5 at higher rpms. its idles at 14.7 when warmed up.

Acetone is something I have been using on/off for about 5 years. you just need a small amount like 2 ounces per 10 gallons of fuel. it works very well in carburator cars and helps a small amount on most,but not all,fuel injected cars. I think it smoothes out the burn rate of gasoline but thats just a theory. theres is alot about it on the internet if you google search it.

The last 2 years I have been running about 30% Ethanol with 87 octane fuel. I have been following your post because I am wanting to goto 100% with a minimal amount of modifications to my injection system. if it goes ok I would then rebuild my old motor and up the compression to take full advantage of Ethanol fuel. its is rated about 105 octane.

wp

[Buzo]

Running our cars with ethanol would be the most incredible project thought!

When switching to 100% ethanol, you must upgrade the components inside the fuel tank. Ethanol is going to corrode any non-plated and copper materials. I'm sure you knew it and are planning for it too.

I know a good source of ethanol-ready fuel components in town, so let me know when you are ready to start and I'll see what I can get for you.

[Buzo]

Question for my friend Cygnus...

I did switch my setup to sequential ignition for a week or so, just enough to measure the new fuel economy and I got 28-29 MPG.

However, I had to switch back to wasted spark because I couldn't get rid of a sporadic loss of synchrony. I'll say 2 loss of sync in a 15 minutes trip.

A loss of sync in Megasquirt means your engine shuts off for a fraction of a second and then turns on again, so you see your rpm gauge going to zero and back. And you fell the engine how it suddenly shakes to one side.

OK, the question. Could you please tell me how is your cam sensor installed in your car? I am doing something wrong, I know it, but after I applied all my knowledge of signal filtering I just couldn't fix that noise that causes the loss of sync. Thanks.

[Oldblueaccord]

It this cam signal wire shielded or with a drain wire possible? it might need to be.


wp

[ecogabriel]

The sensor wires in the EFI cars are shielded; I took the wiring maze apart to repair a broken connector near the distributor and saw the two shielded wires going to the distributor (one CYL, the other CRANK).
From what I have read about EDIS and seeing the sensors and triggers' positions inside the distributor, they should be pretty close and on a solid (vibration-free) surface.... EDIT: I have read your thread and your hall sensor inside the distributor
TIP: you can use the cam sensor from a 86-87 USDM Acura Integra in place of your old distributor. It has a crank and cyl sensor inside. The only modification would be finding a way to screw it to the a20's cylinder head, and possibly keying it differently; otherwise it fits perfect (I tried one in the junkyard). Those sensors are magnetic (is that the proper word?) using only two wires.

[Buzo]

Thanks for your advises. I'll get to fix the cam issue in a short time...

[cygnus x-1]

However, I had to switch back to wasted spark because I couldn't get rid of a sporadic loss of synchrony. I'll say 2 loss of sync in a 15 minutes trip.

Hey Buzo, sorry I missed you question until now. I assume you are still using the 36-1 toothed wheel for primary ignition input? If so then I think the only reason it would lose sync is if the primary input has a problem. The secondary input (cam sensor) is only used to signal whether it's on the first or second half of the engine cycle. In a sequential setup if the cam sensor is lost completely the MS will revert automatically back to semi-sequential, e.g waste spark mode for ignition. You shouldn't notice when it switches. If the cam sensor signals too often (noisy) I think it should do the same thing, but I'm not as sure in this case.

So the sync problem only occurs when you add the cam sensor?

OK, the question. Could you please tell me how is your cam sensor installed in your car? I am doing something wrong, I know it, but after I applied all my knowledge of signal filtering I just couldn't fix that noise that causes the loss of sync. Thanks.

I'm using a hall effect sensor with a magnet buried in the head of one bolt on the cam pulley.






The bolt with the blue on it has the magnet. This picture was taken awhile ago, and looking at it now I'm not sure if the bolt is in the right place. I'll have to double check when I get home later. I've never had a problem with loss of sync so it's been pretty reliable.

I'll try and read through your old threads on msextra.com and see if anything jumps out that could be causing you sync issue.

Using a fuel injection distributor would work for sequential ignition, but since you already have a crank mounted wheel it would be a bit of a step down. Crank based signals are more accurate because they aren't affected by cam belt stretch and vibration.


C|

[defiance]

Wow I like what im seeing here ! So you guys are running megasquirt in place of the stock ecu, and using extra sensors to increase gas mileage ? I like where this is going. any updates ?