JWG

I just installed some 21lb/hr (221cc/min) injectors.

I had dialed in a little too much fuel pressure, because I did not back off enough from running the insanely high psi that I needed to feed the stock injectors enough fuel. Fear of running high fuel pressure for a prolonged time (and putting undo stress on the fuel pump and related fuel system items) caused me to get appropriate sized injectors that I may use now (and grow into as I do a few more mods).

However, with a few days of experimentation, I should have the ideal fuel pressure close to dialed in, and, in a few weeks, I will know exactly where it works best.

For the first time, I saw my O2 sensor spike above 0.6v--all the way to 0.8v on WOT at heavy engine load. I had wondered if Hitachi had even programed the ECU to allow a rich mixture in any mode.

Perhaps my imagination acted up, but I believe that the engine ran a bit smoother with the new injectors; as though it did not have to work as hard to make power.

Needless to explain, I need more seat time, but I thought that some of you might feel interested to know that the ECU appeared to work well with larger injectors in both closed loop and open loop.

Updates as relevant.

snowman '92 100

"open loop" is an oxy-moron... that's weird

moribundman

And "closed loop" is redundant! ;-)

MikTip

How do you measure rich-lean?

JWG

now I can see when the engine runs lean, stoich', or rich "on-the-fly." :-)

moribundman

Typically, the needle will display 0V for a second, then it will quickly jump to 0.6V and fall back to 0V, sometimes stopping for the fraction of a second on the way. At WOT, the needle jumps to 0.7 or 0.8V. The needle spends most of the time in the < 0.5V area. Means I'm running rather lean?

JWG

The existence of oxymorons in our language results from the fact that no one stresses the teaching of any philosophical disciplines (like logic, set-theory, ethics, and linguistics) in school any more. These are the underpinnings of all knowledge, mathematics, and the scientific method. All life-long learners and truely educated persons are essentially philosophers (or as the word means in Greek: lovers of knowledge). Ever wonder why all academics get Ph.D.'s or "Philosophy Doctorates" no matter what their field of study?

Unfortunately, schools make philosophy courses elective if available at all. For some reason, society has associated philosophy with mental ************ (i.e., social uselessness), when philosophy concentrates on education and teaches problem solving--that which all human endeavors seeks to accomplish. Quite simply, philosophers (formally trained or self-taught) have the best problem solving skills. For this reason, they always prove themselves most valuable in their work.

So, shop talk includes oxymorons like "open loop" and redundancies like "closed loop". Perhaps, we should speak of "mapped" and "monitored" fuel injection.

JWG

That is about right for "open loop" or "mapped" fuel injection. My problem: I moved so much air that I could never get it past 0.6v! I always ran lean when I needed a richer mix.

There is a short, but not very good, discussion at the link below. (Best I could do on short notice. Wife's calling, gotta go now!).<ul><li><a href="http://www.gadgetseller.com/gauges/index.htm">click</a></li></ul>

quattro.pilot

what's the increment difference between stock injectors &amp; these 21lbs ones?

moribundman

One's 130k miles old, the other one is about 40k miles old. And both post-cat O2 sensors are also 130k miles old. Aiiiieee!