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Hey, I have a 1993 toyota pickup, v6, 4x4, xtra cab, auto transmission, with 220k miles. I know there are many threads regarding the fuel economy issue for the 3vze motors, but none that i’ve read through quite seem to cover my issues and provide a solution.
My truck i bought about 2 and a half years ago when i was about 14. The truck mostly sat for about two years other than going cruising out in the woods for an hour or two. Once I got my drivers license i started driving it daily, and that’s when the issues started. The truck at first did pretty well on fuel,(do not know exact mpg), but recently started doing very bad and threw a code that was for the o2 sensor, which i then replaced. As of now, my truck is getting somewhere around 8 mpg. Not exactly obviously, but the closest calculation i can get at the moment. I have replaced spark plugs, wires, o2 sensor, distributor cap, and fuel pressure regulator. I mostly drive city, start stop, but i am very conservative with my throttle. After all of that i am still getting about 8 mpg, and i think the truck is also misfiring. I am not positive if it is misfiring but i often hear an “empty thud” sound from the exhaust and the idle will stumble and jump around. I recently cleaned the EGR valve as well as i could and it seemed to have maybe helped the jumping idle but everything is still present. It also has a lack of power from what i can tell, and it has no CEL codes stored other than a code 64 which is a transmission number 3 solenoid issue.
With current gas prices being well above $4 and being 17 in highschool, i just simply cannot afford this mpg. I have been doing research and more research and have found a few things i will try; injector cleaner/sea foam, throttle body clean, and triple check for vacuum leaks. But i really do not think that will help a whole lot and i just want some more feedback on my specific situation as it seems to be a little different than others’. If anybody has any advice i would GREATLY APPRECIATE it, thank you.
Last edited by 93toyota3vze; 03-30-2022 at 01:23 PM.
You can do a "cylinder efficiency test" (who makes up these names?) by removing the plug wires one at a time. If you remove one and the idle doesn't change, that cylinder isn't doing anything. You can check both your ignition timing and spark at each cylinder with a $30 timing light. Remember to use the jumper when checking timing. To check plugs, put your inductive pick up on each wire; if the light flashes the plug is firing.
I would do a compression check, Ill bet you have a cylinder or two down. Probably a tight valve. In that case you will need a valve adjustment….that’s the first place I would look. If your down on power it will kill mileage. Let us know what you come up with. Good luck
I would do a compression check, Ill bet you have a cylinder or two down. Probably a tight valve. In that case you will need a valve adjustment….that’s the first place I would look. If your down on power it will kill mileage. Let us know what you come up with. Good luck
I am not 100% sure if it is low on power necessarily. I know these trucks don’t have much power to begin with, so i do not know if it is around where it should be or not, it just has never had much power. (Not enough power to maintain 40 up a small hill). But i will buy a compression tester and test the cylinders.
Not sure if it is relevant in this case, but i just remembered that when we had the plenum off to replace the fuel pressure dampener, the bvsv, (i believe that’s what it is), had the top nipple busted off so the hose wasn’t connected. Could that contribute to the problems?
And would it be possible for the o2 sensor to go bad this quickly? I have only maybe put 1k miles on the new Denso one since. To check it, what terminals in the diagnosis plug do you use? The link provided by scope103 is not working for me.
Also some more info, the truck starts right up immediately even when cold. Starts faster than my 2012 ford focus, the truck never struggles to start. Also, the idle in park will be high, until i put it in drive or reverse and it will drop to where i’m assuming it should be normally (truck doesn’t have tachometer on dash). I do have 31x10.50 ATs on the truck, when the sticker says the stock size is 225-75-15. So my reading could be a little off but either way the truck is getting horrendous gas mileage.
Last edited by 93toyota3vze; 03-31-2022 at 08:46 AM.
... And would it be possible for the o2 sensor to go bad this quickly? I have only maybe put 1k miles on the new Denso one since. To check it, what terminals in the diagnosis plug do you use? The link provided by scope103 is not working for me....
Hey, I have a 1993 toyota pickup, v6, 4x4, xtra cab, auto transmission, with 220k miles. I know there are many threads regarding the fuel economy issue for the 3vze motors, but none that i’ve read through quite seem to cover my issues and provide a solution.
My truck i bought about 2 and a half years ago when i was about 14. The truck mostly sat for about two years other than going cruising out in the woods for an hour or two. Once I got my drivers license i started driving it daily, and that’s when the issues started. The truck at first did pretty well on fuel,(do not know exact mpg), but recently started doing very bad and threw a code that was for the o2 sensor, which i then replaced. As of now, my truck is getting somewhere around 8 mpg. Not exactly obviously, but the closest calculation i can get at the moment. I have replaced spark plugs, wires, o2 sensor, distributor cap, and fuel pressure regulator. I mostly drive city, start stop, but i am very conservative with my throttle. After all of that i am still getting about 8 mpg, and i think the truck is also misfiring. I am not positive if it is misfiring but i often hear an “empty thud” sound from the exhaust and the idle will stumble and jump around. I recently cleaned the EGR valve as well as i could and it seemed to have maybe helped the jumping idle but everything is still present. It also has a lack of power from what i can tell, and it has no CEL codes stored other than a code 64 which is a transmission number 3 solenoid issue.
With current gas prices being well above $4 and being 17 in highschool, i just simply cannot afford this mpg. I have been doing research and more research and have found a few things i will try; injector cleaner/sea foam, throttle body clean, and triple check for vacuum leaks. But i really do not think that will help a whole lot and i just want some more feedback on my specific situation as it seems to be a little different than others’. If anybody has any advice i would GREATLY APPRECIATE it, thank you.
Probably should check your distributor cap or your timing belt. I got 17 MPG fully loaded on the deck. Wouldn’t also be a bad idea to use a timing light.
Probably should check your distributor cap or your timing belt. I got 17 MPG fully loaded on the deck. Wouldn’t also be a bad idea to use a timing light.
Look for what specifically with the distributor cap? I replaced it maybe 1k miles ago. The timing light will likely also be added to my list. Also, what are your guys’ opinions on seafoam? I know there are many threads but every single one contradicts another. Also if seafoam is something worth trying, what is the best method and how to do it in depth
So far, after changing the distributor cap and rotor, among other things, every spring on my pickup and 87 4Runner, I've gotten 3 bad ones from Napa. They had invisible, hairline fractures that caused all kinds of trouble. One had the center conductor, that sits on the rotor, stuck. It's supposed to be spring-loaded. That one stumped me for a while, I tell you.
Just because something is new, doesn't necessarily mean it good.
Well everything has come to a halt, as the truck started misfiring consistently non-stop
Narrowed it down to cyl 6 and went to pull the plug and the spark plug wire ripped out of the rubber insulation and metal crimp connector that pops onto the spark plug, but it seems like i may be able to repair it.
However, when i actually pulled the plug itself it seems like some threads from inside of the head came out with the spark plug. Leading me to believe the plug was cross-threaded in there by PO or something. I think the plan will be to try a thread chaser with some grease and run it through the head, luckily cyl 6 is one of the easier to reach plugs. Im having trouble verifying the thread size of the spark plug whole, it is M14 1.25 correct?
Also, the spark plug looked like it was only halfway in the head, and the spark plug gap was almost 0
Last edited by 93toyota3vze; 04-04-2022 at 12:22 PM.
03-30-2022, 01:13 PM
