I have an '88 vert and I just did a 13b streetport swap. The car runs really good and feels great at high r's. However during normal driving, it is almost dumping gas ut the exhaust and kind of gutless. I do have a cold air intake and a extremely freeflowing exhaust so I know i'm not geting the back pressure for the secondaries. So they are permanently open which would account for the gutlessness at low r's. I am only getting 12MPG on a good day (170-180 miles per tank). My a/f gauge is telling me it is running lean to stoich, but the people behind me would disagree. Does anyone have any avenues I can explore to maybe remedy my condition. I can't help but think if the fuel mixture was right it would run better. And who doesn't want there car to run better?



Thanks,

Jack

 

I get a solid 20mpg with my vert, but its stock



If I actually get a nice long drive with no traffic and use no AC I have gotten 25mpg if I can remember right.

 

Haha I get like 30+ MPG in my spec V, gotta love the 6spd. But no 12mpg isnt normal, you might wanna get an SAFC to tune the numbers down to get the best mpg.

 

o2 sencer maby?

 

I'm with the drunken idiot. With the streetport, I'm guessing you need some kind of fuel controller that will allow you to tune the fuel delivery. I don't think the stock ECU can handle a ported motor.

 

i've talked to the guys at Hayes Rotary in Redmond, WA, where i got the motor and they said nothing about a SAFC and i thought of the o2 sensor and he said not likely the problem. he keeps telling me the a/f adjusting screw on the pass side of the engine bay needs to be tested. and that brings up another question...is that suposed to change my a/f gauge reading when i adjust that.

 

That's an idle adjustment. It's not likely to have any significant bearing on your fuel economy.

 

Ive herd also oof alot of people not even running 02 sensors and getting better mpg than that.

 

i think otherwise stamped right on it there is an L (lean) and an R (rich) to let you know which way to turn it.

and it does make a tiny difference on my a/f meter but it really affects the way the car runs.

 

haha no 1988RedT2 is 100% right, that only has to do with anything when the car is at idle.