Intermittent acceleration drop

So I don’t have a 3.4 tundra but I had a 4runner and a pickup with that 3.4 v6 and my pickup had this issue. It would loose power, especially on a hill and it felt kind of random.

I cleaned my MAF, new spark plugs, new fuel pump and filter, and finally a throttle position sensor and that seemed to fix it. I didn’t experience it again for the next month after. I did finally get a throttle position error code after about 4 months of having the issue. Wasn’t immediate.

I still planned on doing the injectors, and coil packs as my last resorts. Also grounding issues and clogged cats were recommended to me on this journey.

 

The forums did lead me to checking the brake pedal sensor. Supposedly it can kill the throttle and is somehow hooked to the ECU.

 

I think the 05-06 trucks with the VVTi engines have a different system. I can hold the gas and brake and it won’t cut power, even at speed.

 

ah yes, I forgot the newer ones are the 4.0 V6, I don’t know anything about those haha.

 

FiatRunner, where'd you find the $60 APPS? I'm seeing it for $200 on RockAuto.
I'm going to order it and try it... I want this truck fixed and sold.

 

Here ya go: https://www.ebay.com/itm/1348098691...d6JqMoQ8czsfx-1M2dzse3zKf6XEfEbxoCqY0QAvD_BwE

Couldn't find the $60 one. This was the closest I found.

You might want to disclose to the seller that it isn't a high quality part. There's such an immense quality difference between OEM and aftermarket trucks that I personally wouldn't trust that sensor for long.

 

That's the throttle body side. Rock Auto has the Accelerator Pedal Position Sensor as something different:

 

Shoot. Forgot you've got a V6. I think it still applies though... let me see if I can find a part number for the sensor that's on the throttle body.

Does your truck have a sensor on the actual pedal?

 

I think the sensor is in that base unit that the pedal attaches to.

 

Hmmm. Do you have the 3.4 or the 4.0L engine?

I'm pretty sure that this is the APPS. It's located on the throttle body and looks similar on 4.7L and 00-03 3.4L trucks for sure.

 

2004 is a 3.4L V6.
If so, then someone has something mis-named. I would think the actual sensor (which might be intermittently failing and causing the throttle to go mechanical only) would be more likely to be in the base of the pedal than all the way over at the end of the cable, wouldn't it?

 

I get what you mean. That could definitely be the case- but I know for sure that on the V8 trucks and the 00-03 (unsure about 04) V6 trucks, APPS is on the throttle body. It's built in to the drum that the throttle cable wraps around. 2004 was a weird year- lots of one-year-only changes. I know for sure that the 00-03 trucks don't have a sensor on the accelerator pedal itself. Do the 2004s?

This sensor seems to match what's on the throttle body on your truck. It's listed as the "Throttle body rod position sensor":
https://www.ebay.com/itm/3652328357...h8TZ5Rp4o87rwntuUUVV-VY2p5Gf_PGhoCUVgQAvD_BwE

I don't have experience with the sensor connected to the pedal, only the one on the throttle body. So I can't say for sure if the one on the pedal or on the TB is the issue.

 

Thanks, I've ordered it.

 

It has arrived and looks like a very simple swap-out, except that the sensor is held on by PHILLIPS head bolts for some reason.
The 20 year old bolts don't want to move, and I've already seen my screwdriver strip one slightly. I've sprayed them with penetrating oil, but no luck after 20 minutes. Next step is going to be to close the hood and run the engine for half an hour to warm it up.

 

Impact driver is your best bet. Or Japanese screwdriver hammered into the fastener. I’m sure it’s probably held in with thread locker of some sort, but I wouldn’t expect more than blue.

 

When I was a teenager, I bough one of these to remove Phillips screws from my Honda motorcycle cases. It’s an impact driver and you hit it with a hammer.

 

I'm guessing they're JIS screws, so get some JIS bits off Amazon. Phillips screw drivers will strip out Japanese screws, years of working on Japanese motorcycles has taught me that lesson too many times.

 

Yup, JIS screwdriver that fits the head is ideal. One that can take hammer blows- 2-3 firm taps on the butt of the driver to both seat the driver AND potentially free the bond, then firmly pushing while twisting. You’ll see a shit-ton of import guys in salt areas swear by this method for brake rotors/drums.

I personally have a Lisle impact driver like @bfunke posted. There are a lot of shit ones out there and the ones Lisle makes today are okay-ish, better than any brand you find on scAmazon and many store brands, but they’re not the same as the old ones that functioned more cleanly. You basically need to twist the driver constantly CW or CCW and hold it forward on the newer style one to get it to ratchet in the proper rotation when you strike which was annoying for me. On my old one; which is worn and I’d love to replace, I simply put the driver in the head of the bolt, twist it to set it to drive-in or back-out, then strike away. It doesn’t tend to drift back out like the newer model one does. I ended up returning the newer Lisle, and I’m just dealing with my old one being worn out. I’ll probably break down and try to rebuild the old one, or scour eBay for a vintage one in good shape, since all the new ones I’ve tried feel like shit.

 

I've been pretty happy with this one and a set of decent JIS bits for my Makita driver.

$17 VESSEL MEGADORA IMPACTA Impact Driven Screwdriver +3x150 (6") No.980 980P3150

https://www.amazon.com/gp/product/B003BGTTSE/

 

Thanks everyone
Running the engine for 20 minutes warmed it up. It was about 45* outside. Everything came out easily with the warm engine and my impact driver screwdriver + phillips bit.

 

This is dead-simple, but there's not even a video on Youtube about how to replace it.

First, take a picture of how everything is supposed to look before you take it apart.
I also marked the throttle cable with a sharpie right at the adjuster nut, just in case it ended up having to come loose.

Then I rotated the spring-loaded cable receiver to loosen the cable. I could then pull the cable up into an inverted U, giving it clearance to pivot so that the metal cylinder on the end could slide out the front.

After that, I removed 4 screws, and it came loose easily. The throttle body behind it has a spinning piece that this component actuates. It moves with hand pressure easily and smoothly.

Then I removed the wiring harness. The tab to be pressed down is on the harness plug, not on the body of the component I am replacing. Harness end looks like it's in good shape.

Old and new components look identical.

Bolted it back in, reconnected the harness, put the cable back in, and tested. It functions fine.


I will need to test drive for a while to see if this has resolved the problem.
As far as I can tell, the "sensor" aspect of this is just whatever is coming in and going out of the wiring harness. Maybe there's a magnet that rotates inside?

 

Interesting. FYI, I think we have a member in need right now. I swear I heard @Tundra2 say he needed the outer part of what you’re showing there, his is buggered up and won’t hold the cable in place anymore so it randomly disconnects. Sometimes while he’s driving.

 

Glad it was a fairly straightforward process. Hoping that it fixes your issue!

Won't fit. Part is different between the V8 and the V6s unfortunately.

 

It's for his RCLB which is a V8/4WD. His dad's truck is the V6.

This truck: https://www.tundras.com/threads/crackhead-resurrection.94083/

@J-H he's been thru some shit with it. I know he'd appreciate it heavily, being a new 1st-time dad with limited funds and time, if you were able to work out something with him. At least if you have no intent to use the old part.

 

OP's truck is a V6. Maybe the cable drum can be swapped between V6/V8 throttle bodies? I'm not sure.

 

Ah shit, my bad, you're right.

I wonder if the outer piece is the same? I'd need to dig in the EPC diagrams to see if the part number is similar.

 

Yeah, the one I'm working on is a V6. If it is compatible, I will be happy to ship it to him next week to use as a parts source. I still have the box the new part came in.

 

@Tundra 2, any thoughts? Maybe you can take measurements on your dad's V6 and compare? Although @J-H has the newer VVTi so may be apples to oranges...

 

I put 2 hours of highway driving on the 2004 yesterday with no issues. I'm pretty sure the problem is fixed. I need to clean it up a bit more before I posted it for sale, so I'll keep driving it to be sure.

 

That's fantastic news! Glad it's seemed to work.

Does that confirm my hunch that the APPS is the issue?