New throttle body, same problem

Edited:added bought new from Toyota..

Well shit... I just replaced my entire throttle body with a brand new unit from Toyota and am no further ahead. My truck has the 3.4 and has been running fine except for full throttle or passing gear.

It literally feels like it’s not moving at all when you “punch” it. I had it scanned when the CEL was on and it pointed to the throttle position sensor and pedal position sensor. Now I’m not sure if it tripped those after the mechanic fucked with them or not. He said the TPS wasn’t working properly.

I bought a new complete throttle body and it’s still not accelerating under heavy load. If I let off momentarily, it kinda acts like it’s clearing out. My mileage is horseshit too.

I’m pretty much at my wits end. Could this be a bad EGR valve or plugged converter? The truck idles fine and starts right up. I’ve noticed a ticking or slight ping at mid throttle cruising as well. I really could use some pointers here. Thanks

 

Does the engine rev up easily?
Do you have any current codes?
Can you get current data such as fuel trims?

It probably not likely, but maybe there is a restriction in the exhaust?
It’s not likely with out emissions codes, but maybe?

 

Yeah it revvs normally. No current codes after replacing the throttle body, but I only drove a couple of miles so far. I would have to bring it in to get fuel trims.

 

If you don’t have a scan tool, it might help if you got one.
At least you can see what’s happening as it is acting up.

 

When you say new what do you mean exactly?

New to you? Or brand spanking new? Had your old one rebuilt new? I'm shooting in the dark here because I have a completely different set up compared to you.. but I know I've read issues with other 04 owners on this forum about your TPS is special compared to the rest of the 1st genners

 

It holds a good idle, no evidence of vacuum leaks? Is there a common throttle position sensor issue

 

Sounds like a defective MAF. A defective MAF will drive and operate fine under normal driving condition (and rev fine when in park or neutral - not under load) but when under load (WOT and moving) it'll bog and not want to react.

 

Then any given code is the complete circuit not just the sensor or part in question.

Since it seems to act up only under a heavy load on the engine Has the fuel filter ever been changed lately ??

With this Ethanol gas filters seem to plug far more often.

Then a fuel issue will not trip a code ?

Not having at least a code reader can be quite frustrating.

 

Brand new from Toyota.

The 03-04 were different in the sense they were drive by wire and throttle cable.

 

Yeah I should’ve mentioned that it has a new fuel filter and pump.

 

It’s been a couple years since I’ve cleaned or inspected it. It doesn’t feel like a bog, but more like a big air pocket anything more than half to three quarters throttle is the best way I can describe it.

 

Bad knock sensors or bad coils, bad plug wires will do the same thing FYI

 

As hard as it is to update this, the mass airflow sensor was dirty...

I cleaned it, reinstalled and it runs awesome; no bog or hesitation.

@02hilux you were spot on.
Thanks everyone for chiming in, I think I’ll go hang myself now.

 

Glad you got it fix. Happy camper now, I'll take a 12oz to go