Broken again..

[Perrone]

First my u-joints broke, then my cat was stolen, now I need help once again.

The wife was driving home from work at about 40-45 and said she suddenly started slowing down. She sputtered home and I went out to check it out. Driving around the parking lot once the truck gets to where it should change gears (auto) it starts sputtering and shaking a bit. If you put the gas a little harder it almost sounds like it's back firing (she said it sounds like an old man fart).

I didn't even want to try to get it out on the road to see if it would change gears, but she said it would if you accelerate enough.

I'm low on money as usual so going through a huge list of things to try to replace isn't going to be very easy. After researching it sounds like the fuel pump, but I was not able to find anything telling me how to test it other than testing the pressure. I don't have the tools for this and I'm really don't think it's safe to take on the road to get to someone to check for me.

Any ideas?

(sorry if I left any info out)

 

[fish0281]

I think you can test the fuel pump by turning the key to "on", but not starting the engine, and listen for a whining noise. Not sure if you can hear it on these trucks or not, my old Honda had fuel pump issues and this was always a dead giveaway. Also, the brake system (brake booster) sometimes makes a loud noise when you turn it on, but it clearly comes from the front.

Does it start up right away? Any funny smells? Do all the electrical systems work as usual (radio, dash lights, fans, etc...)?

 

[Doc2012]

Could be a few things.

A Your MAF going out, Spark plugs and wires, O2 sensor.

Honestly, what it sounds like to me is your TPS(throttle poition sensor) is going out.

Mixing too much gas with too little air, causing the truck to sputter, then the fuel gets into the hot ass tailpipe and detonates, causing the back fire.

Do the symptoms go away with more throttle? The higher RPM you hit make the truck seem fine?

What happens if you start to up shift?

Like, if you started out in L, and shifted up through to D. So, L, 2, D.

Any check engine lights?

 

[Perrone]

I think you can test the fuel pump by turning the key to "on", but not starting the engine, and listen for a whining noise. Not sure if you can hear it on these trucks or not, my old Honda had fuel pump issues and this was always a dead giveaway. Also, the brake system (brake booster) sometimes makes a loud noise when you turn it on, but it clearly comes from the front.

Does it start up right away? Any funny smells? Do all the electrical systems work as usual (radio, dash lights, fans, etc...)?

I can't hear much of anything over the dinging it does when I turn it to on. I'll have her check when she gets home since I'm hard of hearing anyway.

The truck starts up just fine with no hesitation and it is idling just fine. When I put it in drive it will roll along just fine it just gets pissed when I press on the gas. I don't hear any new noises when starting it up or anything like that, no smells, and all of the electrical systems are working fine.

Could be a few things.

A Your MAF going out, Spark plugs and wires, O2 sensor.

Honestly, what it sounds like to me is your TPS(throttle poition sensor) is going out.

Mixing too much gas with too little air, causing the truck to sputter, then the fuel gets into the hot ass tailpipe and detonates, causing the back fire.

Do the symptoms go away with more throttle? The higher RPM you hit make the truck seem fine?

What happens if you start to up shift?

Like, if you started out in L, and shifted up through to D. So, L, 2, D.

Any check engine lights?

When my cat was stolen I put in a straight pipe and since they cut so far ahead that I lost my front o2 sensor I extended the rear one to plug into the front. I had a lot of guys here saying it would be fine and it has been running perfectly fine since this happened. The only CEL I have is from missing an o2 sensor.

My spark plugs are only about a year old. I haven't gotten it on the road because it doesn't seem safe, but she did say if she stomped on the gas and just held it that it would sputter and finally shift gears, but she still couldn't get faster than about 30.

I can wait until later tonight and try to get it out on the road when there's less traffic and just hope it doesn't die in the middle of the road I guess.

 

[Stick Figure]

Front and rear o2 sensors are vastly different. the front is an actual air fuel ratio sensor, the rear is only a catalyst efficiency sensor. With out the front I imagine the truck is running rather rich. pull your spark plugs and see if you fouled them running too rich, that could cause your problem right there.

Good article on Toyota o2 sensors http://www.autoshop101.com/forms/h37.pdf

 

[Perrone]

Front and rear o2 sensors are vastly different. the front is an actual air fuel ratio sensor, the rear is only a catalyst efficiency sensor. With out the front I imagine the truck is running rather rich. pull your spark plugs and see if you fouled them running too rich, that could cause your problem right there.

Good article on Toyota o2 sensors http://www.autoshop101.com/forms/h37.pdf

If this is the case and I replace the spark plugs could I get a front o2 sensor and put it where the rear one is now and it be ok?

That actually makes sense because the code I'm getting is po170.

I just watched a few videos of cars with bad spark plugs and that's exactly what my 4runner is doing.

 

[Stick Figure]

If this is the case and I replace the spark plugs could I get a front o2 sensor and put it where the rear one is now and it be ok?

That actually makes sense because the code I'm getting is po170.

I just watched a few videos of cars with bad spark plugs and that's exactly what my 4runner is doing.

be okay? sure. I mean it won't be 100% ideal but should keep it running and driving at least, and not fowling the plugs and washing the cylinder walls. While we are the subject, if you really are running rich enough to foul the plugs make sure your oil doesn't smell like fuel. Excessive fuel in the cylinder will run down the cylinder walls (causing premature wear) and will thin the oil causing bearing problems.