If anyone who has any ideas on why I'm be getting poor fuel mileage please let me know.

I recently bought an 82 Chevy Luv w/ the Isuzu c223 in it, which is supposed to get ~32-36 mpg. I'm getting more like 20-22 mpg. I got 36 on my first tank, but don't know what has happened.

Could a clogged fuel filter do this? The filter was changed about 1000 miles ago. I don't suspect it, honestly, b/c I am not experiencing any other symptoms, such as poor starting or lack of power (although this little rig lacks power on its own).

I also put new shoes on the rear brakes and replaced both wheel cylinders. I'm wondering if somehow the shoes are not returning and causing drag on the drums. This would definitely cause poor fuel mileage! I checked for free spin after install though, so unless my old return springs are broken or bad . . .

Any ideas, especially if you've experienced this before, would be helpful.

Also, there seems to be a little bit more black smoke than there used to be, but I am not sure. I've only had this little rig for about 6 weeks.

Otherwise, it starts and runs fine. I do drive it easy, except for up hills, which require flooring it!

thanks,

Hello Dean
One way to tell if your brakes are dragging is to feel the brake hubs after a drive, if the are warm, that's ok, but hot means the shoes may not be releasing. How does the emergency brake feel? It should have some slack before it grabs. If it is tight right away, maybe back off the adjustment in the cable.
As far as the C223 engine getting 36 miles to the gallon, I wish either one of my Troopers did that well. Maybe when they were new the C223T (turbo) got better mileage than now with 100k plus milage. There is another thread here in the diesel section where we are talking about the injector pump timing after replacing the timing belt, maybe that is the ticket to improved performance.
Brian Rodgers

Welcome, Dean.

As these engines were rated for 58-62hp (depends on the year), holding it to the floor is not unusual when climbing a hill.
I live in hilly terrain, and during the summer, I cart my Kubota compact tractor around on the trailer (about 3000lbs combined, plus the truck), so it spends a lot of time on or near the floor. With almost 550,000kms on this motor, I don't hesitate to hold it there if required. I have learned not to baby it so much, as it was actually causing me problems. I don't try to murder it, but it sees 3000rpms often now.
Speeding is NOT an issue! <img src="/forums/images/graemlins/smile.gif" alt="" />

Dean, I have an 81 PuP. At 65 MPH I get 34.0 MPG. THis is with the tailgate down running either DF2 or Bio-diesel. As for you the FIRST thing to look at is the air filter. If it has any crud on it give it to the trash people.
Second. Tire pressure. Look at the sidewall, inflate (COLD) to the side wall PSI.
You mentioned the fule filter was replaced about 1000 miles ago. You should be OK with that. Fill the tank to the EXACT same place for each refill and calculate your milage.
The C223 is a tough engine and it will last a very long time with clean oil, air and fuel. NEVER exceed 3500 RPM. The engine will most likely explode (this results in VERY poor fuel milage).
I live in Northern VA and if you are near by I'd be glad to stop over and take a look for you.
Or you can come over and pull your vehicle over my oil pit in my garage.Yeah, a real nice thing to have)
Regards!
Eric

Thanks for the input everyone!

After reading Outfitboss's response, I remembered that I had tightened the parking brake cable adjustment right after buying the truck to try and get the parking brake to work. Later, I discovered a faulty mechanism behind the drum! Fortunately, I was able to find a replacement from an Isuzu PUP/Chevy LUV restoration yard and replace the damaged part. Anyway, so I loosened the cable and got 30 mpg on my most recent road trip. This is more respectable. I was loaded down, and have put a topper on that juts out a couple of inches on all sides around the cab, so perhaps these are why 30 and not 34 or 36 mpg.

Thanks for the reminder/advice Outfitboss! <img src="/forums/images/graemlins/smile.gif" alt="" />

Thanks everyone else for the info on the motor/model. I like hearing from other owners of LUVs and PUPs about their truck's performance, etc.

Now I've just got to figure out why it's smoking on me some, not too bad, perhaps just an old diesel (or maybe it's time for a new timing belt?).

-Dean

Cool I am glad I had something to give back to this group, they have been very helpful to me.
Thanks everyone
Happy holiday
Brian Rodgers

Many folks advise that the timing belt be changed after 50,000 miles. If it does break your engine will self destruct. In changing the belt there is a proceedure for checking the timing and you can set the pump timing for optimum performance (power, mileage or whatever).
Don't exceed 3500 RPM!
These engine are BSH tough and will last a long time. I have 220,000 on mine now.
Regards!
Eric

Dean and Eric, you have probably heard about it or at least seen a link to the website but take a visit to www.isuzupup.com This is another great website to be a member at especially for diesel owners like yourselves. Eric, I know you've been a member here for awhile and I wasn't sure if you were aware of the PUP site or not. If you are already a member just disregard the message. The more people the better for the ability to learn and work on the Isuzu diesels.

Salvy