Car started jerking / hesitating under throttle! Help!

[BoyYota]

So today on the way to a baseball game that was gonna be free, my car started jerking when I was attempting to accelerate. It got so bad that we decided to turn around. My brother in law is a mechanic though he doesn't really do diagnostics and such, he's just a street mechanic, and we ourselves couldn't find out what was wrong.

It only jerks when in gear, in motion, and only under heavy throttle. After I took off and blew into most of the plugs that you can find around the surface area of the engine, the car started doing a bit better, but still, if you floor it, it will hesitate and jerk like mad. It does not do this in neutral or park, revs like a champ, and we even put it in drive and gave it gas with the brakes pressed down and it wasn't jerking there either.

I took it to my ASE certified mechanic and he said that he will have to run diagnostics to figure it out. He said a transmission speed sensor would cause weird problems all around and throw a code, and we figure if it was something else like air flow meter, fuel filter, TPS, or CPS it would behave oddly all around and not only when under full throttle and in gear.

I did leave it with him for diagnostic service, but just as a matter of covering all my bases, I was hoping that some of you might have 4/7AFE specific advice on what pops up in your head that may be the major culprit.

[bajaclam]

Usually it's water in the gas. Dump in a bottle of Heet and see if that fixes it.

[BoyYota]

We'll definitely take a close look at the fuel system. I e-mail Scotty Kilmer and the dude got back to me super quick. He said it is about time for fuel injectors or at least a new fuel filter. I have to admit the fuel filter is something I wanted to do when tuning this car up but just never got around to it. When we DO find out if it's spark or fuel and where the problem lies, I will surely let everyone know the outcome.

[zythr]

Originally Posted by BoyYota

We'll definitely take a close look at the fuel system. I e-mail Scotty Kilmer and the dude got back to me super quick. He said it is about time for fuel injectors or at least a new fuel filter. I have to admit the fuel filter is something I wanted to do when tuning this car up but just never got around to it. When we DO find out if it's spark or fuel and where the problem lies, I will surely let everyone know the outcome.

I hope you find the solution.


The Scott Kilmer you're referring to, did he write a book?

[BoyYota]

Originally Posted by zythr

I hope you find the solution.


The Scott Kilmer you're referring to, did he write a book?

Yep, Everyone's Guide To Buying A Used Car, 1994.

You Tube

You Tube

He rocks.

[zythr]

Originally Posted by BoyYota

Yep, Everyone's Guide To Buying A Used Car, 1994.

http://www.youtube.com/watch?v=x8hkrk9lxWw

He rocks.

Cool, He sure does

[BoyYota]

Mechanic said everything checks out fine but it was cutting out on him when it was low on gas and he was taking corners. I have actually taken it out to play before and noticed that it does cut out when you do a hard turn even if there is plenty of gas. So it looks like a fuel pump replacement in the future. For now I'm gonna make sure it's got plenty of gas all the time and do the fuel filter replacement and injector cleaning.