KnightFiyah

So just recently I swear I've been running through half a tank of gas in 2 days. I don't drive very far, and I've even changed my driving habits and reverted to short shifting for better fuel economy and very gradual acceleration to no avail.

Some things to note:

1) My 02 Sensor and Cat were replaced about a month ago, so I don't think they would be the culprit of my poor fuel economy.

2) For some reason, my "trip" odometer is very innacurate. It will show that I've driven, like, 100 miles when I've gone maybe 20. Not sure if this changes things.

3) My engine (the 3VZE) has been diagnosed with rod knock. I'm still driving on it, and it seems to be doing fine, but just something to throw out there I guess.

4) My ignitor has needed to be replaced for about a decade, I still get the same trouble code but the car obviously still starts so I haven't replaced it.

I'm planning to change/check my spark plugs since that's a cheap fix if they have carbon deposits covering them or something but beyond that, I'm not sure where to turn my attention to.

KnightFiyah

Someone help me! My fuel is burning!

85TurboRunner

What was your previous MPG compared to now?

KnightFiyah

I never actually measured it, but I know for a fact that it would take a lot more than 2 days worth of little driving to burn up half a tank. What should I do lol this is my DD?!

BMcEL

Check your actual mileage first. You might get some help if you put a little effort into it.

Basics are cap, rotor, plugs, wires, air filter...have you replaced any of those recently? What, if anything, have you checked? Is your O2 sensor Denso or NGK, not Bosch? It may very well have to do with your ignitor...it's throwing a code for a reason. Have you made sure you're getting a nice blue spark and not yellow? Could also be one or more of the following:

- Plugged fuel filter
- Weak fuel pump
- Failing fuel pressure regulator
- Incorrect ignition timing
- Incorrect idle speed
- Brake drag
- Incorrect tire pressure
- Low compression
- Bad gas
- Gas thief

See what I'm getting at? No one here can pinpoint your problem(s) without any info to work with.

KnightFiyah

Sorry, I didn't mean to seem like I put little effort into my question. I figured poor gas mileage is poor gas mileage.

Anyways, I haven't replaced any of those recently. For the rotor are you referring to the brakes? And what about the cap?

I'll check the brand of my 02 sensor once I get back from a trip. Now that you mention it I've heard certain brands are way better than others.

I started the car today with the hood up and I got a yellow spark..what does that mean?

Thanks again for the elaborate post!

BMcEL

If you don't know what a cap/rotor is, you might want to stay away from the engine with a wrench. But, if you insist, your truck is throwing an ignitor code (maybe, you never mentioned the number) and you have yellow (weak) spark. Try another ignitor.

myyota

I started the car today with the hood up and I got a yellow spark..what does that mean?
[/QUOTE]

You got a yellow spark from what ?.

KnightFiyah

I got a yellow spark coming off the battery I believe, although I only got a quick glance at the spark.

BMcEL

Not trying to be an ass, but you might just want to have someone look at it that knows what spark is.

KnightFiyah

lol I post here because I have little knowledge of cars.

If I wanted to have a mechanic handle these kinds of things I would've brought it to him telling him it set off Engine Code 14 and that I wanted it fixed.

Just hoping you guys could give me feedback but whatever.

BMcEL

See post 5. I'm done here.

bone collector

cap and rotor go on the distributor and are a basic tune up item and need to be changed regularly. code 14 is ignition signal. so you are getting a weak signal. the yellow spark BMcEL was referring too was a spark at the spark plugs not at the battery. yellow is a weak spark, blue would be better. You check it by pulling out a spark plug and pressing the plug with wire attached to the engine block while somebody turns the key and you watch the color of the spark. if you are getting a code 14 and are experiencing poor gas mileage .....heres a thought....start there!! your truck wants to run great and it trying to tell you why its not.....

sechott

Not that we don't want to help but basic knowledge is needed to prevent damage. It sounds that you have no auto mechanic experience. So no one from a remote location can be much help to you.

KnightFiyah

I know basic knowledge is needed to prevent damage, and I do appreciate everything you guys have done to support me. I'm just trying to see what feedback I can get, if any, to give me a better idea of what I'm looking for in terms of solutions.

I'm probably going to be enlisting in some sort of auto mechanic school in the near future, or just work with my uncle on ferraris and various cars in his shop. So hopefully that jumpstarts my knowledge.

bmcghie

Do other people's batteries throw yellow sparks on startup?! Mine doesn't... perhaps you should also check that the wires are properly on the battery terminals, and no corrosion is present.

I can't remember what code 14 is, but I'm pretty sure one of the other helpful members has the factory service manual (FSM) in their signature, which would list said code. FIND the code, figure out what that means, and fix THAT issue. Then see what happens to your mileage.

bmcghie

Yup, BMcEL has the link you need. Still helping, even after he's had enough.

kuzbro

When I start with a used vehicle, spark plugs, rotors/dist. cap (for distributor engines) fuel filter, air filter, battery cables, etc. all get replaced or checked closely. Oil change and coolant are also thrown in for good measure. If you got a rod knocking,....that can be a show stopper. I'd start looking for another engine and engine pulling equipment,...i.e. lift.

I made a 5500 mile trip and found half my air filter half clogged with a mouse nest. K&Ns work pretty decent in spite of restrictions. Anyway, good luck with your endeavor.