well just thought I would post up how much gas im useing see if other are about the same.

JC Cosmo
stock port 20b / stock computer about 65000 km on this engine
only engine mod right now is the intake.

323km 16.6 gals of gas so about 12 miles a gal on a almost 100% stock Cosmo!!!

going to fill up again tonight and check it.

 

Hmmm. .. goofing around with the wideband a little Saturday, I got 100 miles out of 7 gallons. That's about 14.2 MPG. That was cruising at approximately 80 almost the whole way. My applicable mods are nothing more than 3" exhaust, emissions removed, Walbro 255 and E11v2.

I know that Mike was getting around 17 when he had it, but I have goofed with some of the settings and screwed that up. LOL. I'm shooting for closer to 20MPG by the time I leave for California in February.

Reese

 

key is to make it lean in vacuum, like right up to 0psi....

 

Mike, I tried doing that in the middle area of the vac side of the map and it ran fine while I was on the highway. As soon as I tried driving from a stop, the car was acting like it was too lean. (lurching and bucking when I went through those leaner areas).

I'm guessing that part of it is because only the middle of the vac map was lean? (i.e. my 3000 RPM map wasn't a smooth curve towards 0psi, it was actually a bit wavy (like a mild sine wave)?

Help! Heh. Semi-related, how long did your wideband last in the stock location? I'm thinking I might have fried mine. Bleah.

Reese

 

Did you ever get your injectors cleaned and flow tested?

 

Adding a little more fuel to the accel enrichment might help too (if you haven't already). I set the map in my 13B to about 15:1 at cruising speed. It was fine under steady load and I got about 24mpg, but it shuttered a bit under throttle movement. I reduced this problem by about 90% using the accel enrichment correction, but it was still not as smooth as it was at 12.5:1afr. I think part of the problem is that there is some lag due to the location of the injectors in relation to TDC.

 

Thanks for that suggestion, CC. I'll try that as soon as possible.

t-von, yup, the injectors proved to be fine.

 

it was pauls, and it was used to start with, i didnt kill it

 

Adding fuel by throttle pump will work for trasitions when cruising around on a lean map, but if you are getting stuttering and bucking at constant throttle cruise you will just have to add fuel.

Luckily this usually only happens at low rpm (below what you cruise at on freeway). For instance, on my 13BT I have to have it rich from idle to 2,000rpm even in vaccuum and then lean out quickly to stoich from there in vaccuum.

 

I found that on computers that use closed loop O2 , to set cruise afr to 13.0 flat or even 12.90's then with correct o2 settings it will lean out to 15-16 afr's under cruise. That way throttle response is crisp and clean, as well as getting perfect gas milege. If you dont have closed loop (microtech, bastards) you are screwed and have to tolerate one or the other.