$10 DIY cylinder management for honda

[t vago]

For all of those people here who are considering/performed the disabling of one or more fuel injectors to kill pistons to achieve cylinder deactivation:

The dead pistons are still passing air, which still requires work to be consumed. This is work that would otherwise have been used to push the vehicle forward.

Basically, you're burning gasoline to pass air through an engine, and you'd be very lucky to get the same EPA figures for running an engine with dead cylinders, as you would with a properly running engine.

[slownugly]

Yes that's understood from multiple previous threads but what about only doing it at idle once to operating temp? I'll answer my own question by trying it tomorrow when I get to work. I have an afr gauge in my car so it should be easy to tell. Ill take a pic of the afr at idle at operating temp and then unplug an injector and take a pic and see what happens

[t vago]

Originally Posted by slownugly

Yes that's understood from multiple previous threads but what about only doing it at idle once to operating temp?

You mean, instead of having the engine just power the accessories (like power steering, alternator, water pump, and A/C), have the engine power these accessories AND also pump air through itself?

[UFO]

Just an observation - the O2 sensor is monitoring the exhaust in the manifold, and without the injector firing it will read an excess of oxygen and try to richen the mixture. I cannot imagine how this will save fuel or improve mileage especially with only one dead cylinder unbalancing the firing pattern.

[Xist]

I try to save fuel by deactivating all of my cylinders.

[slownugly]

UFO is correct, the only important thing in this topic is what the computer ACTUALLY does when it sees a dead hole. not every car is the same, not every ecu prom is written the same, not every ecu has the same fail safe modes, etc. it is important that we not totally bash an idea because of a hunch we have that it will work or not. especially when no tests have been done to prove the otherwise.

that being said i have no experience in my personal vehicles type of tuning software, im sure others could explain it better. all i can do is post my findings in the mosts scientific way i can, using an afr gauge and monitoring the ACTUAL mixture coming out of my exhaust.

this morning when i got to work i wanted to pull into the lot and recreate a stop light. i pulled in and took a picture of my afr after 5,10, and 20 seconds of running. the afr bounced between 14.5-14.8 and i will include 3 pictures of that. then i walked out and pulled the number 1 injector off. with the notable misfire, the afr proceded to bounce between 17.7-17.9 at the same 5,10, and 20 second intervals. i will include 3 pictures of that. the ecu did not compensate the mixture it simply ran leaner. the only downside is the engine light came on, which i knew would happen. stacy can test this stuff easier because he already has the resistor wired in to prevent the light from coming on.

if the computer doesnt set the light on during the misfire and the same 17:1 afr is coming out of the tailpipe then it might be worth looking into more. this morning was a crap shoot, it couldve went either way. just so happens my ecu reacted in this manner. its not safe to say every other one will do the same

[slownugly]

[elhigh]

^^ You're killing me.

The only way I could do that would be to 1) drill out the little anti-tamper plug that blocks off the adjusting head and 2) attach a long cable by which I could adjust my mix on the fly at the carb.

For some reason I don't think Sweetie would smile on that. She's pretty accommodating about some things, but there's a limit.

I want to save a lot of money on fuel, but I understand divorce is expensive too.

[Phantom]

Unless you have two O2 sensors one for each bank more common on v8s and some v6s, the ECU will see lean and dump more fuel to get it to 14.7. If you have 2 O2s then you just need to send the signal from the one running all cylinders back as both sensors that will be a bit of work or you could create a fake O2 like is used for off road cars with the cat removed to eliminate the CEL.

What would be easier/better for the engine is to custom tune the engine to run leaner when the reading the idle section of the map, if the ECM allows for it.

[gone-ot]

...a case of "unintended consequences" arising from "uneducated tinkering."