Hi everyone,

I recently purchased a s5 vert with a rebuilt engine. As far as I can tell the engine is immaculate, everything looks new, new belts, no leaks, everything works fine, the only thing I can can complain about is the mpg. on a 17 gallon tank I got maybe 230-250 miles.

Just from the smell of the exhaust its pretty clear the engine is running very rich but I've never owned anything like this before and considering the condition of the engine, I'm not sure where to start looking.

Help anyone?

Chris

 

The EFI isn't all that different from a piston engine. A good starting point would be to check the fuel pressure and make sure it's within spec. It should be within 27-33 psi with the engine at idle, rising to 34-40 if you unplug the vacuum line from the regulator.

 

Rx-7s in general run rich. Does it smell rich when the car is warmed up? If so it may be the car is not going into closed loop indicating a possible problem with the o2s.

Also 230-250 out of a full tank is decent, which tells me you are probably running normal. I get about 220 out of my car.

 

It definitely runs rich all the time whether the car is warm or not. I will check the fuel pressure to see if it is in spec.

 

I will check the 02s but are you telling me 12-13 miles per gallon is normal?!?!

 

17 to 24 I think is the specs.. But city is like 15 ish

 

A lot of people claim 10-15 lol, I know if I am really on it and racing all the time especially in the canyons I will definitely get 10. I can get 25 if I am doing 85 the ENTIRE time and not change the throttle at all. I found this out driving on I5 going down to 7stock.

 

Wow okay, Fuel Pressure is right on and the oxygen sensor is working, I don't have to tool to test O2 sensor sensitivity but it looks like I'm doing pretty good on mpg.

Okay so rx7's tend to run rich in general, I've read somewhere that they tend to backfire as well, Is this normal and are these two related?

 

are you on slcrotary.com? there are alot of locals to you that have fcs that could help.