Laggy Bottom End

fltnlow · #1 (**permalink**) 03-11-2003, 08:34 PM

is it just the nature of the iforce to have a mushy bottom end (torque) or is it something else not letting the engine make the power its capable of? ive asked a couple people and ive been told the tundra's have a "speed sensitive fuel pump" and this is why they are like this. i was thinking about putting in an in-line fuel pump anyways and a fuelpressure regulator just for the hell of it. is it part of the restrictive exhaust? anyone have any thoughts on this?

v8Toilet · #2 (**permalink**) 03-11-2003, 09:27 PM

Yup! First thing I did was adjust the fuel pulse damper located on the drivers side fuel rail 1/2 turn counter clockwise. This was the optimal position for my engine but it might not be for yours. It eliminated the bog off the line and I picked up 2/10's in the quarter mile or I went from a 15.7 to a 15.5. My 60-foot time went from 2.4 to 2.3 also indicating that I gained low-end torque. I did this per a recommendation of Nitrousfed. He claims that the I-force v8 is detuned by Toyota in this way. I don’t understand it totally but I know when I turn that small fillips screw ½ turn it makes a major difference. Hodgeee tried this adjustment and his truck ran worse so not all of them are the same.

Second thing I did was replace the stock muffler with a Spintech muffler and kept the stock piping. I tried the TRD dual exhaust and lost major low-end torque so I recommend that you don't go that rout.

Third thing I did was add a TRD air filter (Thanks Hodgee) and that in conjunction with the Spintech muffler has had a positive impact on power and low-end torque. See what Hodgeee found here No Loss in any power to date with mods.

Last thing I'm going to do is replace the stock exhaust manifolds with either the soon to come S&S headers or the JBA headers.

redbaron224 · #3 (**permalink**) 03-11-2003, 10:43 PM

Quote:

Originally posted by v8Toilet
Yup! First thing I did was adjust the fuel pulse damper located on the drivers side fuel rail 1/2 turn counter clockwise. This was the optimal position for my engine but it might not be for yours. It eliminated the bog off the line and I picked up 2/10's in the quarter mile or I went from a 15.7 to a 15.5.

Where is this damper, do you have a pic? What do you mean when saying "but it might not be for yours?" How can I tell if this is a concern with my engine? More torque would be great for me while pulling the travel trailer.

Thanks,

v8Toilet · #4 (**permalink**) 03-11-2003, 10:45 PM

I'ts dark now! I'll take a picture and post it later.

v8Toilet · #5 (**permalink**) 03-12-2003, 05:31 PM

Here it is. Make sure you mark the position of where it was before you move it so that you can return it back to stock settings in case you have too. Most Tundra’s according to Nitrousfed come from the factory with the screw bottomed clockwise. The stock setting on mine was 1/4-turn counterclockwise from being bottomed out clockwise. I have it set at 3/4-turn now.

You'll have to play around with it too see if there is any room for improvement.

v8Toilet · #6 (**permalink**) 03-12-2003, 06:25 PM

Not that I noticed!

03TundraTRD · #7 (**permalink**) 03-12-2003, 06:33 PM

Hey v8 so can this be done on a 2003 v6 and also where is the fule pulse damper

redbaron224 · #8 (**permalink**) 03-12-2003, 07:33 PM

Thanks V8, can't wait to try it.

v8Toilet · #9 (**permalink**) 03-12-2003, 08:54 PM

Because the injectors operate on a pulse, they open and close very rapidly. This may cause undesirable fluctuations in the fuel pressure. The pulsation damper smoothens the fuel pressure fluctuations. The injectors operate on a pulse, they open and close very rapidly and this may cause undesirable fluctuations in the fuel pressure. A pulsation damper is mounted on one of the two fuel rails to dampen pressure variations due to the rapid opening and closing of the injectors.

Nitrousfed told me that this was a fuel pressure regulator so if someone has a factory manual than please look it up and let us know for sure. All I know is that my engine feels stronger when I back that screw out and I went from running 15.7 to 15.5 in the quarter mile when I changed the setting and my 60-foot time improved from 2.4 to 2.3. I also don't have that bog off the line either.

moosehead9 · #10 (**permalink**) 03-12-2003, 09:04 PM

Yes, there is a fuel pressure regulator...it is located on the right
fuel rail. The pulse damper is on the left side of the engine.

03TundraTRD · #11 (**permalink**) 03-13-2003, 09:59 AM

So can someone tell me exactly where is the Fuel pulse damper on the V6 and would I benifit from this mod

ricqik · #12 (**permalink**) 03-13-2003, 10:19 AM

Quote:

Originally posted by moosehead9
Yes, there is a fuel pressure regulator...it is located on the right
fuel rail. The pulse damper is on the left side of the engine.

Did you mean left and right like driver and passenger or left and right like when facing the truck??

v8Toilet · #13 (**permalink**) 03-13-2003, 12:27 PM

Pulse damper is on the driver’s side for v8. I don't know about the v6.

03TundraTRD · #14 (**permalink**) 03-13-2003, 05:23 PM

So does anyone know where the Pules damper is on a V6

moosehead9 · #15 (**permalink**) 03-13-2003, 09:29 PM

I mean left and right like driver and passenger. I always do it that way because that's how it is in the shop manuals and