Sluggish throttle response

[slukas]

Ever since new (2005 quad cab 4X4) my truck has had sluggish throttle response when floored. The truck only has 11,000 miles and you pretty much have to count to three before the turbo spools up and the truck begins to accelerate from dead stop or while in motion at any speed. I hear so many stories of how fast other members trucks are and I am aware that not many are stock either but is a stock truck supposed to have that much throttle delay. I believe my truck is getting plenty of air and fuel because I have removed the aircleaner lid and ran it without an air filter for testing purposes and there was no difference. Also my tail pipe has black soot all over it so I know that must indicate that there is not a shortage of fuel. My truck is strictly stock and has never been to the dealership accept for an oil change. :{

 

[Pawpaw]

My truck is stock and yes, it is a dog off the line from idle. What you and I are experiencing is called turbo lag. The turbo won't build much boost below 1500 RPM.



Is your truck an automatic? If so, you can hold the brake while depressing the accelerator. When you reach around 2,000 RPM, release the brake and you will be amazed how the beast will launch. Just don't blame me if you break your transmission. That's a lot of torque from a dead stop.



Bob

 

[robertyoke]

Simple thing to check for would be fuel filter if you have not changed it, change it. I would check for codes even if the mil is not on.

If the truck misses/surges/bucks I would check transfer pump pressure.

Also look for soot around the exhaust manifold/ head gasket and turbo to exhaust manifold gasket. Any drive pressure loss will delay fueling by not letting the turbo make boost.

-robert

 

[GECCO]

I agree with PawPaw, you are simply experiencing turbo lag, my truck does the same thing and is perfectly normal.

 

[TSpecht]

Don't floor the throttle right off the bat. Roll into the throttle gradually. My truck is amazingly quicker (seat of pants measurement) when you let it build a little boost while rolling into it rather than just hammering the throttle to the firewall. I think it's got something to do with emissions and so forth so it doesn't smoke like crazy at lower RPM's when you mat it without having the turbo spooled.

I wouldn't mind a way around that part of the program, but with practice rolling the throttle down seems to be pretty easy to do and seems to be the way to go in fact...

 

[slukas]

Thanks guys for your input and at least I know that I am not alone in my experience. Unfortunately it still bothers me but if there is nothing else I can do than I will just live with it.

 

[Bob4x4]

Don't floor the throttle right off the bat. Roll into the throttle gradually. My truck is amazingly quicker (seat of pants measurement) when you let it build a little boost while rolling into it rather than just hammering the throttle to the firewall. I think it's got something to do with emissions and so forth so it doesn't smoke like crazy at lower RPM's when you mat it without having the turbo spooled.



I wouldn't mind a way around that part of the program, but with practice rolling the throttle down seems to be pretty easy to do and seems to be the way to go in fact...

That is right,if you stomp it to the floor the timing instantly retards... ... ... ...



Bob

 

[slukas]

That is very interesting I am definitely going to try that technique. My question is why would the computer retard the timing?

 

[Bob4x4]

That is very interesting I am definitely going to try that technique. My question is why would the computer retard the timing?

Emmisions compliance... .....



Bob

 

[formula]

Mine does the same thing. If the turbo isn't already spooled then flooring the throttle doesn't do much. 1/2 throttle works better and roll into it like the others have said



The lag you feel is mostly electronic and is for emissions purposes. I guarantee you that my 1st gen would light my '05's turbo in about 1/2 a second :-laf Mechanical injection, foot = fuel, and smoke



Sean

 

[OHale]

I installed the Rokktech modified crank sensor and that got rid of my lag.



I put the stock sensor back in last fall because I was having some pinging and I thought the Rokktech might have been causing it. It turned out I had dirty injectors. I had forgotten I had left the stock sensor in and thought, 'what's wrong with my truck?' when trying to get out into traffic from a dead stop. Oh yes, the turbo lag, I forgot. I put the Rokktech back on. For the lag alone it has been worth the $70.

 

[slukas]

OHale you are the best. Finally a viable solution. Where do I order this Roktech modified crank sensor and how easy is it to install. Again thanks.

 

[OHale]

OHale you are the best. Finally a viable solution. Where do I order this Roktech modified crank sensor and how easy is it to install. Again thanks.

Hi slukas,



The site is: http://www.rokktech.com/_mgxroot/page_10437.html.



Also, http://www.rokktech.com/_mgxroot/page_10433.html . They have a good write up there.



You should search the 3rd gen forum for Rokktech sensor. Not all members are having the same experience. At worst, some show little or no improvement, some a lot. My truck is slightly noiser (more 'diesely') with the Rokktech. It makes the off-the-line spool up much quicker for me. Some people are getting better mileage; sometimes I think I do, sometimes I don't.



Have a good one!

 

[swexlin]

Don't floor the throttle right off the bat. Roll into the throttle gradually. My truck is amazingly quicker (seat of pants measurement) when you let it build a little boost while rolling into it rather than just hammering the throttle to the firewall

Yep, what they all said. It takes practice. I have learned NOT to "floor it" when needing to make a quick left turn when there is a break in oncoming traffic. Yes - I have to do that. Around where I live, there are many interesections (I go through a couple everyday on my commute) where there is NO left turn signal, but should be. When there is a break, you have to go - NOW!! One time I stomped it, and the truck went - nowhere. Not a good feeling when there was a car bearing down on me.



Now, I "roll" it, and she moves out pretty good.

 

[OHale]

OHale you are the best. Finally a viable solution. Where do I order this Roktech modified crank sensor and how easy is it to install. Again thanks.

I forgot to answer the last part of your question: it is very easy to install. Remove a hex bolt, unplug the sensor from the harness connector and reinstall the new part in reverse order. You can then adjust the advance by rotating the sensor while the bolt is loose.

 

[slukas]

Thanks OHale, I ordered the sensor today and it sounds pretty easy to install. I appreciate the input from everyone.