Poor Gas Milage
Pro
Joined: Apr 2005
Posts: 603
Likes: 2
From: Illinois, USA
Originally Posted by gerry72
I would first ask: What method are you using to compute your fuel economy?
I actually am using shareware software called "Automotive Wolf" that allows me to enter each time I fill up, the mileage, and all the goodies. It then shows me the MPG (I don't do partial fills). The mileage has actually improved by 3 MPG since I got the car, but there was plenty of running in the garage, where I get 0 MPG.
Normally, I calc by dividing the miles on that tank by the gallons dumped -- my tripometer works, and this confirms the what the software is telling me. I also have the software to show trends.
Is that a reasonable method?
Brian.
Drifting
Joined: May 2005
Posts: 1,629
Likes: 4
From: Somers CT
Originally Posted by 77 Vette Girl
'77 350, Stock Q-Jet just rebuilt, 16.25 MPG Hiway, Starts good when cold but really hard to start when engine is warm or hot. Garage smells of gas. Please tell me more about the "gas continuing to pour out after turning off" ....is this a float level problem?
Bill
Drifting
Joined: Nov 2001
Posts: 1,469
Likes: 6
From: 68 427 4.11s Roadster
Originally Posted by bobs77vet
you would be surprised what a difference lock up makes on my car with a 2500 stall speed 700r4....its about 4-5 miles per gallon difference
C3nMe, I have a notebook that allows me to do the same thing
Also if your timing is wrong its bad milage. A stretched timing chain can have an incredible impact on milage too.
You can check timing chain with 1-2 tanks of fuel and incredible driving self control. You have to drive very easy with very low accelleration. If milage skyrockets you have a bad chain.
Or you physicaly check it.
Pro
Joined: Apr 2005
Posts: 603
Likes: 2
From: Illinois, USA
Originally Posted by Techno
C3nMe, I have a notebook that allows me to do the same thing
Also if your timing is wrong its bad milage. A stretched timing chain can have an incredible impact on milage too.
You can check timing chain with 1-2 tanks of fuel and incredible driving self control. You have to drive very easy with very low accelleration. If milage skyrockets you have a bad chain.
Or you physicaly check it.
Also if your timing is wrong its bad milage. A stretched timing chain can have an incredible impact on milage too.
You can check timing chain with 1-2 tanks of fuel and incredible driving self control. You have to drive very easy with very low accelleration. If milage skyrockets you have a bad chain.
Or you physicaly check it.
Well, there is no chance of me driving anything gingerly -- I have never babied any car I own (after all, that is why I put on a street & slalom suspension package?)
What I can do, however, is put a timing light on it and gun the throttle and see if the timing is "stable" or does it jump around a bit between accel and decel ...I seem to recal this being a diagnosis for a bad chain.
Of course, with a few thousand miles on a a rebuild, I hope it's not bad -- if it is, then bubba was even more bubb-ie than even I gave him credit for.
Brian.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
I went from 10 to 16 after converting from computer controlled to non-computer controlled... Oh and a $500 trip to the dyno shop hah. However my engine has like a few thousand miles on a complete rebuild, even one of the heads is "new." (one was cracked beyond repair so we got another one with the same casting number)
As everyone has said, check that timing!
As everyone has said, check that timing!
Instructor
Joined: Aug 2005
Posts: 104
Likes: 5
Originally Posted by TopGunn
Not a float level issue, the primary jet wells sometimes leak around the plugs in the bottom of them. The gas then drips down in the intake after the engine is shut off, and is difficult to start when warm because it gets flodded. A common fix is to epoxy them with something like JB Weld to stop the leak. I did mine last year and either didn't get all the leaks or there's another issue, I still get smell from time to time.
Bill
Bill
Thanks Thom
