B27 fuel conumption

[Ingars]

hello!

i'd like to ask to share your experience on either a 262 (my case) or
any other volvo running with a B27.

i recently bought a 262c bertone and it appears to be very greedy on
gas. not that i expected wonders, but currently it appears the car is
making about 12 mpg, which seems kinda low to me, given the engine has
about 80k miles (140k km) on it, no oil consumption, all working fine
and clean. the first question though is - is this normal? the second is
- what might be wrong (most common fallacies of this engine showing the
discussed sympotms, your experience)?

thanks,

ingars

 

[User]

hello!

i'd like to ask to share your experience on either a 262 (my case) or
any other volvo running with a B27.

i recently bought a 262c bertone and it appears to be very greedy on
gas. not that i expected wonders, but currently it appears the car is
making about 12 mpg, which seems kinda low to me, given the engine has
about 80k miles (140k km) on it, no oil consumption, all working fine
and clean. the first question though is - is this normal? the second is
- what might be wrong (most common fallacies of this engine showing the
discussed sympotms, your experience)?

thanks,

ingars

B27E and B27F are similar but not identical. Most B27F motors had
computer feedback systems and a lazy or inop O2 sensor would cause the
system to go rich. The CI fuel injectors would spray inefficiently and
cause the fuel consumption to be high. Vacuum leaks around the injector
seals would cause high fuel consumption. If the car has been sitting a
lot it's possible that the screen in the control pressure regulator is
restricted and pushing the fuel control pressure high (4.9-5.0 bar vs
variable low side pressure starting at 1.7 bar and rising to 3.7 bar).
High control pressure reduces the amount of fuel injected but being
overlean while underway requires more fuel to generate adequate power.
If it has a frequency valve to regulate fuel distributor lower chamber
pressure be that that it buzzes and that the relay is working properly.

Bob

 

[James Sweet]

hello!

i'd like to ask to share your experience on either a 262 (my case) or
any other volvo running with a B27.

i recently bought a 262c bertone and it appears to be very greedy on
gas. not that i expected wonders, but currently it appears the car is
making about 12 mpg, which seems kinda low to me, given the engine has
about 80k miles (140k km) on it, no oil consumption, all working fine
and clean. the first question though is - is this normal? the second is
- what might be wrong (most common fallacies of this engine showing the
discussed sympotms, your experience)?

thanks,

ingars

That is pretty low, you should get more like 16-20 mpg, still low, but
better than what you get.