2005 TUNDRA bogging down when I punch the gas, also doesn't start on 1st try

I have a 2005 Toyota Tundra v8 with a 4.7L and when I hit the gas hard the engine bogs down. When I try to start it, the vehicle starts and dies but starts on second try. I've replaced the plugs, coil packs, MAF sensor, Timing belt and water pump so far. Any recommendation would be greatly appreciated.

I'm thinking either a the catalytic converter or fuel filter but that's only a guess.

Thanks in advance!

 

I never recommend throwing parts at any issue. Do you have any frayed wires or loose vacuum lines on visual inspection. Particularly did you correctly route the crank position wire to protect it from the serpentine belt? What codes is it throwing? If you haven’t yet, read @shifty`s Megathread. Might also consider cleaning your throttle body and MAF sensor. Then disconnect the negative battery terminal to force the ECU to relearn.

 

Failing cats produce an awful smell usually. If they are really clogged you can hear the difference at the tail pipe. You’re sounds like something else to me. Bad plugs, or bad timing. Could be one of the sensors, but they normally throw codes. What it’s almost never is the fuel filter.

 

Rotten eggs. Or if you've ever worked in a restaurant and used a flat top grill brick, that's almost exactly the same smell.

@sgrassau if you replaced your coil packs with anything other than Denso brand, put the factory ones back in. Aftermarket on that specific part is utter garbage. Same problem with the MAF sadly, if you didn't buy Hitachi, which was OEM, reinstall the old MAF.

On your problem... if there was no change with spark plugs and coil packs, and assuming you used the correct Iridium plgs, which you should use on the VVTi trucks - my first thoughts are:

1. When was the last time the timing belt was changed, and was the crank position sensor wire properly routed so it won't get nicked by the belt? This is a VERY common issue, and crank position sensor harness must be damage-free or the ECU won't supply power to the fuel pump.
2. You may have a fuel delivery issue, or an air intake/air monitoring issue. I suspect fuel delivery, but you didn't bother to tell us mileage, or if the fuel pump has ever been replaced, both of which are pretty critical details!
3. This could be something stupid simple like you made the poor choice of adding a K&N style intake or oiled filter, which tends to clog the throttle body with oil/garbage and/or let excessive shit into the engine and/or restrict airflow

If you need pics of the crank position sensor routing, search for the phrase CRANK POSITION inside this thread: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

I'd be hitting the parts store to get a can of CRC Throttle Body cleaner. I'd be pulling the negative battery cable, and cleaning the throttle body the proper way. i.e. never spray anything directly into the TB, never wedge the throttle plate open, never let the throttle plate slam shut. Spray the TB-specific cleaner into a cloth (drench it), and wipe the rim and plate until your cloth comes back clean. Reattach the battery cable after 10 minutes, being off-battery will force the ECU to re-learn, expect the truck may run a little funky for a few miles, but this is sort of a mandatory thing any time you change anything related to air/fuel delivery or monitoring.

I'd drive to test. Any improvement?

Fuel-wise, '05-'06 have no fuel filter, so there's not a ton of other stuff to go wrong here. However, two things: Aftermarket fuel pumps are notoriously shit these days. Denso (the OEM) brand fuel pumps are great, but sometimes the fuel pickup tube will unseat from the pump in some years, and cause symptoms like you're seeing. The only way to catch this is to drop the tank, OR to watch fuel pressure during startup to see if it's unexpectedly dropping. If it is, you know without a doubt it's related to fuel pump, but again, it could be failing fuel pump resistor, relay, fuel pump, etc. There are test procedures for each, which you'll find the Service Manual, which is linked for download in that thread up there ^^