# Toyota loses tons of gas mileage please help! **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** corolla, fuel-economy, toyota\ **Created:** [November 28, 2009, 2:09pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067 "2009-11-28T14:09:50Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 28, 2009, 2:09pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/1 "2009-11-28T14:09:50Z")
1986 toyota corolla gts (ae-86) my friend owns and says that over a course of three days he lost half a tank of gas from driving to school and back which in total is only about 15 miles or less. we have checked for leaks and the spark plugs and the wires are good. we are about to check the O2 sensor to see if its failed. we any and all suggestions. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [November 28, 2009, 2:31pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/2 "2009-11-28T14:31:17Z")
He “lost” half a tank of gas? Or does he think that he actually used/burned that much gas? You tell us that there are no apparent leaks, so the implication is that the car actually used 1/2 of a tank of gas to drive 15 miles. This leads to two possible conclusions: 1. The car is in very bad shape mechanically. 2. The gas gauge is not accurate. On what is he basing this estimate of gas usage? If he is basing it on gas gauge readings, please remind him that a car gas gauge is not a laboratory-grade measuring device. He needs to calculate the amount of gas used by filling the tank and dividing the number of miles driven since the previous fill-up by the number of gallons needed to refill the tank. If he does this, and averages his calculations for three fill-ups, I can virtually guarantee that his car is not using 1/2 of a tank of gas to go 15 miles. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [November 28, 2009, 2:49pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/3 "2009-11-28T14:49:32Z")
Check for a thermostat that’s stuck open, a choke that’s stuck closed, or for a faulty Thermostatic Vacuum Switching Valve located on the thermostat housing. Tester ---
**Author:** ![edb1961](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/edb1961/32/122_2.png) [@edb1961](https://community.cartalk.com/u/edb1961)\ **Post date:** [November 28, 2009, 2:57pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/4 "2009-11-28T14:57:21Z")
Is there a possibility that the gas was siphoned out of the tank? Otherwise checked the mpg as suggested by VDCdriver. Ed B. ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 28, 2009, 3:15pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/5 "2009-11-28T15:15:25Z")
thanks ill tell him ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 28, 2009, 3:17pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/6 "2009-11-28T15:17:57Z")
will do. did you own one of these Tester? ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 28, 2009, 3:18pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/7 "2009-11-28T15:18:49Z")
dont think so. its very hard to get the gas tank open trust me its taken me 5 minutes to get it open with the normal lever before ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [November 28, 2009, 3:35pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/8 "2009-11-28T15:35:43Z")
No. Never owened one. But repaired a lot of 'em. Tester ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 28, 2009, 7:32pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/9 "2009-11-28T19:32:39Z")
that must have been fun. ---
**Author:** ![hd72mm](https://avatars.discourse-cdn.com/v4/letter/h/9fc29f/32.png) [@hd72mm](https://community.cartalk.com/u/hd72mm)\ **Post date:** [November 28, 2009, 8:27pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/10 "2009-11-28T20:27:09Z")
Someone stole his gas or his gauge is wrong! ---
**Author:** ![galant](https://avatars.discourse-cdn.com/v4/letter/g/77aa72/32.png) [@galant](https://community.cartalk.com/u/galant)\ **Post date:** [November 28, 2009, 11:17pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/11 "2009-11-28T23:17:15Z")
Knowing the car and its audience I have a bias. So I say someone took the car out for a joy ride. ---
**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\ **Post date:** [November 29, 2009, 12:19am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/12 "2009-11-29T00:19:02Z")
No chance the gas is in the crankcase? Let all the other readers know your 02 sensor checking method. ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 29, 2009, 12:30am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/13 "2009-11-29T00:30:16Z")
we checked the O2 sensor by the book by shorting 2 of the terminals in its service connector and then connecting a volt meter to 2 terminals and kept the engine at 2500 rpm and it was suppose to deflect more than 8 times in a 10 second period and it deflected 13 times so its good ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [November 29, 2009, 12:50am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/14 "2009-11-29T00:50:05Z")
One other thing. Pull the dipstick out and smell the oil. If it smells like gas, the diaphram in the fuel pump might be leaking. Tester ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 29, 2009, 1:00am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/15 "2009-11-29T01:00:34Z")
the fuel pump is in the gas tank and the car is fuel injected not carburated so how is it possible for the 2 to mix ---
**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\ **Post date:** [November 29, 2009, 2:17am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/16 "2009-11-29T02:17:49Z")
An injector that is constantly being told to fire is one way, I have seen a pinched wire harness do this (caught under the valve cover after a valve adjustment) ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 29, 2009, 2:26am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/17 "2009-11-29T02:26:45Z")
would cracked or broken fuel injector connectors cause them to short and continue firing? ---
**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\ **Post date:** [November 29, 2009, 3:26am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/18 "2009-11-29T03:26:21Z")
No, I can’t picture how, the failure would have to be in the harness or fuel injector its self, Hey have you checked fuel pressure? perhaps it is way high ---
**Author:** ![teenchanic09](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/teenchanic09/32/1210_2.png) [@teenchanic09](https://community.cartalk.com/u/teenchanic09)\ **Post date:** [November 29, 2009, 3:31am UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/19 "2009-11-29T03:31:01Z")
no we havent guess well look at that tomorrow. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [November 29, 2009, 11:22pm UTC](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067/20 "2009-11-29T23:22:00Z")
Your friend must have the 4AGE engine, if its an AE86, then its rear wheel drive. This is a vary popular vehicle with the drift crowd and gets a high price on the retail market. I think, but not 100% sure, that this engine has a cold start injector. It could be leaking. When it leaks, it leaks into the intake manifold. The excess fuel washes down past the rings into the oil pan. This is why several people have asked you to check the oil for the smell of gas. [Next page](https://community.cartalk.com/t/toyota-loses-tons-of-gas-mileage-please-help/40067.md?page=2)