Throttle response

[TW1]

I bought an '03 HO 6-speed a month ago and am thrilled with it. I pulled the 5th wheel with it the other day and was amazed at the difference in power between the new truck and my "old" 2000 47RE equipped truck.

My question is this: When I shifted gears and lifted my foot off the accelerator from WOT, there was about a 1/2 to 3/4 second delay before the engine would start to deaccelerate. What causes this delay? Is it normal, and if it is normal, what can be done to change it?

 

[DPKetchum]

Its normal and has been in some old threads. Different answers to why its set up to do this. I think its emissions related same as gas autos did this. Burns off any excess minor amounts of fuel in cyls. I think someone else said to prevent turbo bark or uneven pressures. Could be wrong. But it is in the design.

 

[JHardwick]

You can't shift it like a gasser. Once you have reached the RPM that you intend as a shift point, lift you foot slightly to maintain that RPM for a split second. This will allow the motor to defuel. If you really push it hard and immediately lift the throttle/stab the clutch ... . the motor will actually GAIN rpm!

 

[BHaner]

Something else that's neat... I noticed when i was going up a hill at my house... if you put it in second... and dont touch the accelerator. . it will add more fuel by itself! Just enough to keep an idle going up the hill... Nomatter how steep the hill is. . it wont bog the motor down!

 

[TW1]

Thanks for your responses. We just got back from a trip and my wife asked me why I was revving the Dodge up to 3000 before I was shifting, and I had to tell her I was practicing my WOT shifts. I then had to explain to her what a WOT shift was and why I did not know how to do that before; obviously she thinks that I know it all... I wonder why? It coldn't be because of anything I have told her in the past, could it?

If anybody would like an Erickson Aircrane sticker, write me and let me know your snail mail address.

Thanks again,

Tom

 

[Steve M]

There's also a TSB for this characteristic. If your throttle crank is located under the driver's side battery instead of on the driver's side of the motor like the first vintage, you might have a sticking throttle. The bellcrank rubs on the bracket it's mounted in. The fix is fairly simple. A new bracket and you're back on the road!

 

[BSkinner]

Originally posted by BHaner

Something else that's neat... I noticed when i was going up a hill at my house... if you put it in second... and dont touch the accelerator. . it will add more fuel by itself! Just enough to keep an idle going up the hill... Nomatter how steep the hill is. . it wont bog the motor down!

Yeah, that happened to me and was a great surprise. I was idling up a very steep, wash boarded, gravel road and was going as fast as I wanted to and was ready to slow down and put it in first because I was about to bounce off the road. About the time I was ready to make the shift, it seemed like the rig kind of accelerated right at a place that I really needed to slow down (steep drop off on side of road). Now I know what to look for.



Bob

 

[JHardwick]

This comes in handy when hooking up a trailer, especially on uneven ground ... ... ... ... ... ... . with your foot on the brake, engage the clutch a little and use the brake to move the truck ... ... ... . better than 3 pedals with 2 feet