Poor MPG / California ECU - I think I may have found the problem!

[ssybert]

Hi Guys,

I've got a 96 Metro 3cyl manual. I bought it with a bad transmission and the first thing I did was replace it along with a clutch. A 3cyl transmission wasn't available anywhere (for short money that is) so I went with a $200 4cyl transmission. I was getting 45 or better mpg. It was great but not what everyone else was reporting. The tranny wasn't geared for my underpowered car and eventually I got stuck on a steep hill trying to get out of my job site, got mad....long story short, I needed another clutch. I figured since there just wasn't enough grip on this clutch and the tranny wasn't matched well to the car I'd go for a swift GT flywheel and clutch and a 3cyl tranny. Everything is now perfect. Couldn't smoke the clutch even if I tried (well maybe I could). Problem now is ever since the swap my mileage has been NO BETTER than 40 and that is at EXACTLY 65 mph.

THe car was originally purchased in NH and driven to California for 8 years. then driven back to Massachusetts where I bought it.

My question is, if the car was driven to california, to pass emissions there would the previous owner have been forced to replace the original computer with a california one? If so, how can I identify this?

I'm wondering if the good mileage I was seeing was from the 4cyl lower geared tranny on the 3cyl and the poor mileage now is because of a california computer in there. Maybe I've been chasing a ghost that didn't exist all along.

Thoughts?

~Scott

[Crvett69]

if you car has 13" wheels your tranny gear ratio should be 4.39, the 4 cyl one you put in there was like a 3.73 or higher, thats why you had no power but better mileage, a 3 cyl tranny from earlier metro will have a 3.89 (xfi) 4.10 or a 4.39 (convert)

[ssybert]

well my RPM definately went up when I put in the 3cyl tranny. I'm around 3050 or so @ 65. The computer I think is my biggest issue. Need some high level tech input on this one