For some odd reason I'm getting about 130ish miles to the tank. I can still lay rubber from standstill, acceleration is fine, and no noticable issues driving or idle.

Oil change, coolant change, and tune up were done in july and the car sat during august.
Servivce engine light has popped on for a few seconds then gone back off three times this week.

Also noticed heater not blowing heat, but figure that'* the blower motor.

Going for a diagnostic tomorrow morning, but was wondernig if anyone had any ideas?


*******EDIT********
1993 SSEi (guess that'* what trm means)

Tune up: plugs and wires (found out my brother had another tune up done while I was gone for a weekend, seems 2 wires were crossed)

Oil change was oil and filter

*****EDIT*****
Sadly I forgot to look at that as I was filling the tank. Since I'm at just over 1/2 tank I can run it to an even 1/2 the top off to find out.

First off, what year and trim level is the car?

Supercharged?

What all was involved in your tune up?

We need more info

Lets also find out what your " a Tank" is. How many Gals are you putting in when you fill it up?

You should BOLD your edits... makes them easier to spot
even better would be to actually post them up instead of editing your previous post ( if you are asked for more info ) This way we know you replied.


I also have a '93 SSEi, and I can beat on it pretty severly and still nail at least 280 - 300 miles per tank ( full tank -- about 1/8th tank )

You also should change your fuel filter, air filter, O2 sensor, PCV valve.....

What plugs did you use?

Any check engine lights on?

Check all vacuum lines

What does your boost gage read at idle? how about wide open throttle?

There are a TON of things that could effect mileage.... lets start narrowing this down

If possible, look under the car and trace the fuel lines.... is there any chance you might have a leaking fuel line?

also dont forget Driving habits

i got only 13mpg once...

But yes, we need more info to help you out

Sorry, I thought it was better (manner wise) to just edit instead of adding new posts.

When I asked my brother he just remembers getting delco plugs.

Check engine light has blinked on 3 times in past week, It was only on for a few seconds when it did come on.

At idle boost gauge hovers just above -10, at WOT it bounces slightly just above max.

I'm not gearhead enough to know which are teh vacuum lines...sorry.

I did notice that I seem to have too much oil. So I'm bout to change that.

Was told told delco platinum plugs were used.]


Oh, my driving habits aren't bad, average speed is around 40/45 mph. On the highway I do around 75 mph. I don't really punch it unless I need to move through a turtle maze.

Platinum plugs are not good for a supercharged motor. Replace them with copper plugs.

How old and what brand is your O2 sensor?

Just got back from shop...seems my O2 was running backwards and adding fuel since it thought it was running low instead of reading it running rich.

So now I have to drive it dry and start over to see how my mileage is now. Also gona slap on another tune up. So with that in mind which would be the best plugs for my stock 93 ssei.

The thread for tune ups hurt my brain since i don't have any mods.

Your O2 wasn't running backwards, and your mechanic is a pure imbecile. O2'* will run you rich when they get old and tired.

Run NGK TR55 plugs at stock gap.

Yea sounded crazy to me also, but that'* why I posted what I was told. I even had one shop tell me I didn't have a SC in my car despite it sitting on top of the engine, so I didn't stick around that one too long.

I was in such a rush yesterday, I forgot to ask if i should go for certain wires aslo.