Poor gas mileage,step inside
Thread Starter
Drifting
Joined: May 2003
Posts: 1,647
Likes: 28
From: Woodbridge NJ
Poor gas mileage,step inside
My 84 gets about 6 mpg city driving. No codes, no black smoke on start up or during driving. Its a little better on the highway, maybe 10 or so. Hit the control to show instant average and it reads 25 mpg.
Where do I start? I can't afford to even pull the car out of my driveway.
Where do I start? I can't afford to even pull the car out of my driveway.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Well for starters you can look at the basic tune-up stuff. Plugs, wires, fuel filter, air filter. Then I would find a way to put a scan tool on the car and see if the O2 sensor is working correctly. If it isn't you can replace the O2 sensor. If it still doesn't improve you may need to check the emissions stuff. A clogged catalytic converter can shoot your gas mileage to hell, but if the mileage is that bad I would think that you would feel a very substantial power loss.
Thread Starter
Drifting
Joined: May 2003
Posts: 1,647
Likes: 28
From: Woodbridge NJ
I did a complete tuneup, plugs, wires, K&N air filter and fuel filter. The cat is gutted. The car runs quite well for an 84 with 167,000 miles. Starts right up at 1100/1200 RPM's, then gradually settles at 700 RPM's. No hesitation when I hit the throttle. I pull no codes from the computer.
I may just go for the O2 sensor. Is it possible the previous owner played with the chip? As I memtioned the car runs great, just very poor gas mileage.
I may just go for the O2 sensor. Is it possible the previous owner played with the chip? As I memtioned the car runs great, just very poor gas mileage.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Originally Posted by Brimis
I may just go for the O2 sensor. Is it possible the previous owner played with the chip? As I memtioned the car runs great, just very poor gas mileage.
I usually don't like just throwing parts at the problem, it would be good if you could scan it and watch the O2 activity before replacing it. As it is though an O2 for your 84 should cost $20 at best so it might not hurt if you don't know the last time it was changed.
Instructor
Joined: Jan 2005
Posts: 138
Likes: 0
From: Germantown OH
If you haven't already, try visiting the Crossfire Forum. I have learned a lot about my '84 from those guys.
http://www.crossfire.homeip.net/
http://www.crossfire.homeip.net/
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Racer
Joined: Jul 2004
Posts: 308
Likes: 0
From: Christiansburg VA
It's a total shot in the dark...but have you considered the possibility of some kind of gas leak?
I had a similar problem with my old Scout years ago. It ended up being a leaky fuel pump.
I would make sure to check your tank, lines, filter, etc. to see that all of your fuel...is actually making it to your motor.
Best of luck.
I had a similar problem with my old Scout years ago. It ended up being a leaky fuel pump.
I would make sure to check your tank, lines, filter, etc. to see that all of your fuel...is actually making it to your motor.
Best of luck.
Elite Torch Red Member
Joined: Sep 1999
Posts: 57,805
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
As suggested above, calculate the actual MPG by noting your gallons at fill up vs miles driven, also, have yoy tried resetting the MPG on the car?
Remember it doesn't reset itself.
If I didn't reset my MPG, I'd only be getting 10 MPG, especially after a run at th etrack.
Remember it doesn't reset itself.
If I didn't reset my MPG, I'd only be getting 10 MPG, especially after a run at th etrack.
