Poor gas mileage on 74 Dart

  • Thread starter Deleted member 22463
  • Start date
-
D

Deleted member 22463

Guest
Hi guys, hoping you all can offer me some advice. I've been driving my 74 Dart SE now for almost 5 months. I had to do some work to her when I bought her - tune up, a new starter, tires, and a new carburetor (one appropriate for the engine, she is my daily driver after all). My problem now is gas mileage. She's running a stock 318, and the carb is a new Holley. Everything I have read online says the car should be getting at least 15 MPG, and the old heads have said that she should run closer to 20. I don't do much highway driving, but the car is running at about 8.5 MPG consistently. I don't mind the mileage, but if everyone is saying I should have better fuel economy, I figure something is up. I don't haul *** with her, either. Maybe you all could give me some advice on things to check out and possibly address? Anything is appreciated. R
 
need more info, rear gear, what type of holley, 2bbl? 4bbl? dual exhaust or not?? I would assume electronic ignition, like stated above make sure your vacuuum to the dizzy is hooked up and working, what is timing set at. is it advancing and how far..
 
Make sure float level is correct; idle mix set correctly;choke opening fully; advance timing degree or two at a time to find engine's "sweet spot", make sure air filter is clean. Check front end alignment, and the ever popular tire inflation.
 
Thanks guys. I'm back in Phoenix now after a vacation back east. My mistake on the carb, it is a 4 barrel Edelbrock (I'm having trouble remembering the size off the top of my head). Car is single exhaust, should be standard rear gear (if you can't tell, I'm rather new at the whole car thing, and I'm not from a Mopar family). Air filter, tires, and front end alignment are all good. I need to check out the vacuum advance, and some of the old heads also recommended changing the timing chain. Thanks again, R
 
I'll be doing the timing chain in the next week or so. Don't have the tech to check the vacuum advance right now. If my reading of the Haynes manual is right, the car does not have an oxygen sensor, leaving potential problems with the catalytic converter or the injectors. Aside from those two things, can you guys think of anything else it might be?
 
Ended up replacing the advance and the distributor, which turned out to be fubar'd. Thanks for the advice fellas, I'll let you know how she does with the mpg's over the next week or so.
 
You must log in or register to reply here.
-

Back
Top