Does your rpm "flare" inbetween shifts on 6spd?

[geusterman]

Talking with a TDR advertiser about buying a G3 and he related all the good stuff but told me that the engine rpm goes up when you clutch to shift and found that irritating. Is that still the case? Sounds pretty weird. geusterman

 

[Diesel Nut]

Mine did at first, just had to get the feel for the throttle and all. 02 did it to me too, moving up frome a 93 was a bit of a change. Once you get used to driving the truck, it doesn't happen any more.

 

[BSkinner]

My truck surged when new. I either got used to it or it doesn't surge anymore. Or, maybe a combination of both. It was kind of annoying as I wasn't used to that kind of thing happening.



Bob

 

[Prairie Dog]

Ditto for me. It got better and I got used to it pretty fast. It doesn't do it at all after 3rd gear. Not a big deal IMO.

 

[Floor It]

Cummins has addressed this issue, its due to the high pressure of the common rail. When you push in the clutch pedal and let up off the throttle pedal at the same time, the high fuel pressure can not bleed off fast enough, so there is a slight surge in RPM.



John

 

[JohndeereG]

When towing

I only notice the rpm surge when towing my gooser. I reduce my throttle slightly prior to applying the clutch. After a while you won't think much of as it will come second nature to you.

 

[realsquash]

Mine does this "flare". If you're passing in traffic and you've really put the hammer down and let up quick it will continue as if you still had the pedal floored!! It's a scary sensation the first few times it happens!



It seems like if you are in 6th gear passing someone with the throttle down all the way, if you just let up a tad bit it pulls harder, too. I would guess it's the same issue but I'd really like if it was fixed.



Andy

 

[geusterman]

I wonder if it is the same with the automatic. geusterman

 

[Steve M]

There's a TSB for this. The throttle bell crank under the driver's side battery rubs the bracket it's mounted to when you give it full throttle. The fix is a new bracket that clears the bell crank.

 

[geusterman]

Thanks Steve. Made my day. geusterman

 

[rbattelle]

Mine used to do this, but I have since learned to compensate for it and it never happens anymore unless I want it to.

 

[Floor It]

I have the auto and the bell crank doesent hit anything and if I floor it in low gear and then let off it will still act like its floored for a mila second. Its just the way it is,like some here have said you learn to compensate for it as you get use to it.



John

 

[Steve M]

https://www.turbodieselregister.com...e=15&highlight=sticking throttle&pagenumber=1

 

[Jengle]

I will have mine here in a few weeks and can tell you if it does that too. FWIW, the model I test drove at the dealers, shifted just fine when driven normally. It did exhibit the symptom of not reducing rpms when shifting at the redline. I was told by some that this was a part of the programming to reduce or eliminate the Turbo-bark when you have a lot of boost going and slam the throttle shut. Again, when shifting normally before redline, the throttle acted perfectly normal. Good luck with yours.

 

[Scrappy]

flare-up

Mine does it too, but if I let up on the throttle just before I shift it won't do it. Just gotta work on getting the timing down on my shifts in this truck.

 

[HVAC]

Mine Does It Too

I notice it when I'm accelerating hard. Like the dash pot on older cars that didn't let the idle drop when you came off the throttle.

 

[Floor It]

Its rail pressure, plain and simple.



John

 

[Prairie Dog]

I don't understand the rail pressure theory. Shouldn't the pulse duration and timing control the situation? Gassers have had the equivalent of HPCR for years and don't suffer from this phenomenon. I'm not arguing here, just trying to figure out whats happening.

 

[Floor It]

Puse and duration is when and how long the injector sprays fuel. The fuel pressure raise's as RPM and throttle postion change,so if your really into it at upper rpms and the throttle is pedal is close to floored the fuel pressure is going to be around max PSI. So, your up in rpm's and full throttle ( or close to it) and you let of the throttle and push in the clutch= rpm surge,because that much fuel pressure can not bleed off fast enough. As for the gassers, they dont run anywhere near the pressure that we do. My friends camaro tuned port runs 75 psi at the rail, and thats turned up from stock. We are around 23 to 26 thousand PSI.



John

 

[HVAC]

Rail Pressure

I think John's onto something here.



My shift flare seemed to be more noticable once I became EZ equipped. The EZ increases rail pressure.



Guess I need to get some larger injectors to allow the rail pressure to drop quicker:-laf