Hello everyone, I'm new here and have a problem with my 92 4cylinder 4runner. I would greatly appreciate any insight on these symptoms.

The full story: The truck would start fine, but every now and then when attempting to accelerate from a stop, it would just go pretty slow and not take more fuel even if you floored the gas pedal. But eventually it would suddenly work fine and the throttle would be fully responsive.

I took it to a mechanic and got the fuel filter changed, put in some injector cleaner, tune up, oil change/new oil filter... everything seemed fine.

Then a new problem started where it would run perfectly normal if you didn't give it much throttle, but as soon as you give it more - to get up a hill or speed up quicker, it would start jolting and cutting out, very similar to what would happen if you're running out of gas. There's no check engine light or anything...

I've taken it back to the mechanic and he double checked the fuel filter job, checked the fuel pump pressure, it's showing 60psi.... but he doesn't seem to have a solid idea of what the problem could be.

Soooo I was hoping the experts on here might be able to give me some suggestions. Anyone had anything like this happen?

 

Check your TPS.

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

I'll get on that, thanks. I don't know anything about this stuff so even the obvious is lost on me. Thanks again

 

also injectors could be dirty

 

My moms car had a similar issue, you could push on the gas pedal and nothing and then it would just take off! the brakes wouldn't work either, it was the o2 sensor.

 

Wouldn't a faulty AFM do the same thing?

 

Faulty AFM's seem to get alot of different problems when they start crapping out.

 

to clarify.... the o2 sensor caused the brakes to not work ?

 

I had a similar problem with my truck, messed with it on and off for the better part of a year! It finally manifested itself on a trip to the Death Valley backcountry. What I found was there was an incredible amount of rust in the fuel tank. When the fuel would get bounced around, the rust would get suspended in the fuel and plug the pickup sock, starving the truck for fuel. After a while, the rust would settle out of the fuel and the truck would run okay. Don't think it can't happen as my truck has never left the desert south west, yet still had a rusty tank. And I noticed you're from up north.

Drain the fuel, drop the tank, pull the fuel pump, and look in there with a flashlight (and don't smoke while you're doing this LOL).

If you're good with Google, you should be able to find a new tank at a very reasonable cost, if that's what you find.

John

 

Yea that sounded odd, i'll try to rephrase, it felt like the gas pedal and brake pedal were down at the same time. maybe the higher RPMs made me think that but we could be sitting in traffic and it would jolt forward a lot, even if we had our foot on the brake.

 

check engine light or not. check for codes. just check for codes. gotta check for codes. dont replace anything else, just please check for codes.

if you dont know how pull your diagnosis cap and look under it. the two terminals shaded or marked get a staple or similar metallic object to connect them together. turn key to "on" note flashing check engine light sequence. report back. or buy a 30$ book and it will tell you what the flashies mean.