Hey, my stock 88 GTA is getting something like 12MPG for city driving, is this a little low? 350 with automatic. Also I notice my gas gauge fluctuates alot, as much as 2 notches. Im not just talking about during turns, even when just going straight.

 

could be better could be worse. my TBI got about that city driving

 

12mpg is horrible, I get 18 mpg with my setup.

Glenn on here gets 30mpg, but has done some computer mods.
I would think you should be at at least 20mpg.

Done a tune up lately?

 

I did a tune up a few months ago, you think theres deffinitly a problem?

 

I'm not too familar with emission equipment, but did you replace the O2 sensor?

 

yeah try the o2 sensor. that can fix a fuel problem.

because when the o2 goes, the fuel mix gets all screwed up, or does the ecm go to limp home mode?

 

It'll run rich with a bad 02 sensor.

My 350 IROC gets between 19 and 20 all the time.

 

hmm, how much for a mechanic to swap an O2?
When you guys are talking 20mpg, you all know im talking about city driving right?

 

i get 15 city. always have, always will... until i do some computer work.

 

I was getting 13 mpg city/highway mix. Nothing brought it up for me. Then I put in 24lb injectors and it skyrocketed to 17mpg.

I decided I just needed to get into my computer.

 

does it run rich and rich and rough at idle?

i also think changing the O2 sensor should be about $30 labor to pay + the sensor so about 60-65 total are rent the o2 socket from autozone for 15 bucks then get it back when u return it so u save 30 bucks
and also check/change the egr

hope this helps

 

who? me?
If so, it doesn't seem to run rich. I have a miss in my idle that I believe is due to a sticky valve. I'm bringing it to Snap-On Diagnostics (where my dad works) and we're gonna throw it on every bit of equipment they have.

 

City MPG is a completely subjective and unique measurement. You can't compare your city MPG numbers with other people's because everybody's 'city' is different. On guy might be talking about stop signs and red lights every block, significant traffic, etc. Another might be talking about mild suburban driving. IMO the only way to guage your city MPG is to keep track of what it does over time in the same conditions. If you notcied it starting to go down, you know you have a problem.

Highway MPG can be pretty fairly compared though since you should be talking about basically open road cruising.

 

You're getting a mechanic to do it? It's really quite simple, about 15 or 20 minutes. I've done mine twice now.

 

I don't know, since I measure fuel consumption on the TA in furlongs per cubic inch. got a conversion chart?

Your results may not be that bad if you are driving in stop-and-go traffic, AC on, and have that ThirdGenner tendency to "test" the posi unit every once in a while...

 

Yes, my car seems to "suffer" from this problem. I think ive killed maybe 4 minivans and smoked a few volvos by now. Mohohaha. Oh yeah, I got my license yesterday hehe, happy birthday to me.