Lousy gas mileage Dodge 360 | Joined: Sep 2016 Posts: 90 journeyman | OP journeyman Joined: Sep 2016 Posts: 90 | I took the Dodge camper on a 300 mile trip this weekend. Keep in mind the wind was blowing harder than I've seen in a long time . The Dodge was a handful even at 55 to 65 mph . But I only got 8.9 mpg that's horrible. I'm wondering if I should start replacing parts. Start off with new plugs and wires. possibly replace the Coil , it's the original possibly the brain box computer. Sometimes when you floor it It bucks and stumbles, but only sometimes , let off it and floor it again and it's fine. Hummm. oh I very recently had the Rochester 4 barrel rebuilt. It seems to run really well. I think the fuel pump needs replacing. I still have to crank on it to start it.
1988 Dodge B350 1ton 360 motor 727 3 speed trans 4 barrel Rochester carb.
Last edited by Jerry_XtraVanTastic; October 08th 2017 7:46 pm.
| | | Re: Lousy gas mileage Dodge 360 | Joined: Nov 2013 Posts: 2,321 Likes: 156 veteran | veteran Joined: Nov 2013 Posts: 2,321 Likes: 156 | Hi Jerry,
Hightops are a handful! Not the ideal situation for gas mileage. I run stiff Bilstiens and tires. Air bags run seperately, plus the factory Hellwigs in the rear. All that helps quite a bit in the wind. Cuts way down on the Pucker Factor.
My experience with mechanical fuel pumps is when they fail, yer not going anywhere. With a computer, you may not be able to alter the coil, depends on how electronic your ignition system and the distributor is.
A tune up never hurts if it's time, especially new wires. Cap and rotor for sure. Plus a quality oil change. That has got every vehicle I've owned through smog in Cali. Well, except for the 298000+ mile 2.8 v6 in the S10...
My '88 318 has throttle body FI. The '94 360 in the Xploer has MPI. There's a reason Dodge went FI...
If thats a computer controlled carb and your accelerator pump works? Sounds like it's as good as that carb will be. The only carb I have on the 4.3 Chevy in the Searay does the same exact thing as yours.
The 727 doesn't help. Xplorer's are heavy. Carb, no OD. Might not achieve much gain, but the motor will be happier.
I prefer all the engine and tranny mounts be solid, so I can apply power firmly to the ground so I can enjoy not achieving great mileage while driving the V8s.
How is the exhaust? No matter whatchure talkin about, a clog is never ever a good thing.
Good wrenching, and Happy Vanning! | | | Re: Lousy gas mileage Dodge 360 | Joined: Mar 2016 Posts: 339 enthusiast | enthusiast Joined: Mar 2016 Posts: 339 | 1 ton, 360, high profile and wind? 9 is about right.
Tucson-it's a dry heat...like an oven
| | | Re: Lousy gas mileage Dodge 360 | Joined: Sep 2016 Posts: 90 journeyman | OP journeyman Joined: Sep 2016 Posts: 90 | Hi Wedgy an H ben s thanks for responding Ya the exhaust seems ok never had it checked. Sometimes it sounds like it might have a leak by the header . I should have it checked to be sure. For the most part the exhaust is solid. You may remember I had a busted Rt rear leaf spring and the rear was way out of alignment, that will really kill your gas milage. Try Crabbing down the highway. Anyway that's fixed. It tracts much straighter now. 9 miles per gallon in 50 mile an hour cross wind . Ya it was a trip, not fun But I kinda was hoping for better. The engine seems to have more power since the carb rebuild. The guy said It definitely needed it. He did a lot to it. Even fixed the butterfly. Drilled and plugged the bottom. All kinds of little things. This guy is good.
I'll do a basic tune up next week and check a few things out closer like the EGR valve. Also have the front end inspected as I may need new parts on the front suspension. And I'm sure this has the original shocks on it. Definitely need replacing. I have new tires on it last year. I don't have a lot to spend on this , but I think it will be worth it in the long run. Thanks | | | Re: Lousy gas mileage Dodge 360 | Joined: Aug 2001 Posts: 12,107 Likes: 37 Maniac | Maniac Joined: Aug 2001 Posts: 12,107 Likes: 37 | (1) if you haven't had the catalytic converter replaced, at least get it checked. Carbs and cats don't mix well. Carbs can't keep a tight enough control on the fuel mixture to avoid excess fuel getting to the cat and causing an internal meltown. I have seen it happen. If yu are runing the original cat it probably has faile dinternally and is causing a restriction inthe exhaust.
(2) ignition system condition is very important. Verify the mechanical and vacuum advance systems in the distributor are functioning properly.
(3) if all is going well, a 360 high top van MIGHT get 12-13 MPG on a good day.
If I wee you, I would focus the ignition system and making sure all the vacuum lines are hooked up properly and not leaking. If you have a lean-burn ignition or carb system, you should really consider ditching it and converting to a standard non-computer controlled ignition/carb. Get a factory service manual and go through the regular maintenance items. Don't just through new parts at it.
Windows- they're what make a van worth owning! | | | Re: Lousy gas mileage Dodge 360 | Joined: Dec 2014 Posts: 396 enthusiast | enthusiast Joined: Dec 2014 Posts: 396 | Same exact problem here. 1984 Dodge B350, 360 4 barrel, Thermo quad. Re built it my self, it still runs rich. Plugs get fouled after a while.
If, i can ever afford it, its getting a better carb and maybe A better intake. Edlebrock has a good pair, but, for about 500 bucks.
Dual exaust might help. But, the way dodge designed these things The gas tank is in the way of a second pipe.
I would love to hear suggestions or tricks. Anything without a microchip. I have no electronics and would like to keep it that way. | | |
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