Maximizing fuel efficiency 93 b2200 fuel injected

Hello I have a 93 b2200 that just sucks gas back. It's fuel injected. I get around 22-23 mpg on highway which is ok but then in the city I'm getting like 12-14 mpg. I've changed the plugs and wires to NGK. Replaced fuel filter. I know there's going to be a drop in city vs highway but that's a pretty big drop and I've heard of people getting 30 mpg no problem with these trucks. Are the carb trucks better on gas than the fuel injected? I'm going to replace o2 sensor and clean up my fuel injectors and maybe check out the air temp sensor. Is there anything else I could do to get better milage?

Sounds like you need a tune-up. I would definitely look at the injectors, if they are leaking you won't get good mileage. Cleaning the MAF may help too.

Replacing the O2 will also help if it's old.

You may want to physically look at the ECU for burnt capacitors etc... Usually the 2.6i ECUs are prone to failure but sometimes the 2.2 will fail.

Dan

I would test every sensor, if you have access to a service manual, it will give you a reading (usually in ohms) that a sensor should give in certain conditions, also do a full tune up. Something as bad as a faulty temp sensor could fool the ECU into thinking the motor is at -40

I hsad a '93 (carbed) that I couldn't get to go into closed loop.

Turns out the wiring harness had corrosion built up on it where it grounded on the intake manifold, so none of the sensors that fed off that ground could find it. Fooled the ECU into open loop operation, too. Took a lot of time with a multimeter to find the excessive ohm's resistance.

Maybe you have something stupid simple like that, too.

Hope this helps.

Yea I'm hoping that it isn't something snall and simple that's easily overlooked. Alright thanks for everyone's input I'll start working on this stuff.

As I understand from your other thread you have a Haynes manual and have already done a basic tune up.

If you have a Haynes manual you should have a pin-out diagram for the ECU. That is the picture of the ECU 34 and 20 pin block. With that and a digital multimeter you should be able to troubleshoot your poor mileage issues. You can test the oxygen sensor, for example.

Please don't start any new threads about this issue; just add to this one as you progress through your repairng it. It will be too hard to keep up with you otherwise.

I only started this one because my check engine light did turn off so thought I would do one specifically for poor mileage as it seems it's a separate issue. I'll only use this one from now on and will give updates when I do this work. I'm gone working for two weeks now so it'll be awhile. Thanks for your input it's much appreciated.