Rb30 Patrol Fuel Consumption Issues

[erall0]

hey guys I got a rb30 patrol with 33inch tyres I have converted it to efi and im having economy issues

im only getting 120khm to 40ltrs of fuel its got a new afm and new air filter its running nicely any ideas why its using so much I was getting 550 -600 out of it when it was carby

[Ben C34]

What about o2 sensor? Is that new and all hooked up correctly?

[erall0]

as far as I know its hooked up correctly is there a way to test it ? would it cause that much drop in economy the way its hooked up is white -ecu black -ecu red- positive

[Ben C34]

Can be checked with a multi meter and best to check on the ecu pin. Google what to expect when checking it.

That's extremely bad economy so I wouldn't think just o2 could make it so bad.

Have you checked the ignition timing?

Would be good to see of the ecu has any fault codes, but that would assume you have wires it all up to the consult port or engine check light.

[erall0]

timing is 15c +2 advanced im using 98 octane fuel no ecu errors im going to replace the o2 sensor if that doesn't fix it maybe I got leaking injectors

[blind_elk]

So what exactly did you do to convert to efi? ECU? Fuel pump? Fuel pressure?

Does it seem to drive any differently?

(highly unlikely the O2 sensor will have ANY effect, especially if you are in a city.)

[Ben C34]

So what exactly did you do to convert to efi? ECU? Fuel pump? Fuel pressure?

Does it seem to drive any differently?

(highly unlikely the O2 sensor will have ANY effect, especially if you are in a city.)

That's a funny question. I would love to see how someone could convert to edit without changing the pump and regulator. And ecu.

The O2 sensor has a big affect on consumption. Google it.

Not big enough to explain this but easily 15 percent.

Edited January 4, 2015 by Ben C34

[blind_elk]

Just for Ben:

What ECU is being used? Factory? Chipped? Aftermarket?

What fuel pump?

What is the fuel pressure?

And the O2 sensor will have absolutely minimal EFFECT on fuel consumption in city, ie stop / start, driving. The O2 sensor only contributes when in closed loop, ie constant throttle, driving.

[Ben C34]

The O2 sensor allows the ecu to control fuel.mixtures in closed loop at low load as you know.

It also is used by the ecu for long term fuel trim , which is applied when in open loop. When the O2 sensor isn't working correctly the ecu runs as rich as it can (has been programmed for ) as a safety measure. Therefore regardless of what style driving you do, a non functioning o2 sensor will increase fuel usage.

[Dobz]

Have you check water temp sensor?

3km/L seems very excessive. Is there a lot of black smoke coming out the exhaust while driving? I know you said it's driving nicely but I can't see a car driving too nicely when it's using that much fuel.

One thing I'm having trouble understanding is how you were getting 13.75-15km/L on an engine moving a 2T car in the first place.

Edited January 7, 2015 by Dobz

[XKLABA]

What was the economy before you put 33"s on it

And did you correct the speedo, if not how many kms are you actually doing

[AngryRB]

From my previous experience with weirdly high fuel consumption, i found the purge control and fuel return line plumbed up wrong, check that your fuel return is on the pump properly or else the intake manifold will suck up fuel straight from the tank under vacuum from the manifold, in my case my consumption was 20L/100km and came down to 12L/100km which is quite a difference, also consider the fuel reg which can leak raw fuel into the intake.... You will want to sort this out cause it will lead to premature wear on the cylinders, and could result in piston slap from having the cylinders constantly being washed and running dry...

Edited January 11, 2015 by AngryRB