Why Zero Throttle?

[Gbrady]

What is the point of zero throttle? I have been driving standard shift for 40 years and have never had a problem not having it. Cars, trucks, motorcycles, tractors, dozers, and all sorts of equipment. The few times in all the years that it may have been a little easier you could count on one hand. Is it to make up for lack of driving skill? Is it the fact they can't make a good heavy duty auto trans, so they make a semi auto that you have to shift? Having never had a problem not having it, I have read of complaints of the engine speed surging during normal driving and when backing up with trailers. It would seems unwise to turn the engines throttle over to a computor that can not judge the enviroment it is being used in. That is what a brain is for. The only way to drive the six speed when parking or backing up a trailer in tight spots is with the clutch. Why is it not an option that can be disabled? I do not like having my driving programed at the factory. I would rather control of the throttle than have the computor do the driving. Is it really that hard to push the throttle? I can not see the bennefits out waying the risk.



Gary Brady

Palcios, TX

 

[rbattelle]

I must confess ignorance to what you're referring. Are you talking about the idle speed governor, which holds idle speed despite changes in load? If you are talking about that I fail to see why this is a bad thing. You'd prefer the engine stall out if you give it some clutch and no throttle at idle?

 

[John - K5AWO]

The reason the throttle cable does not control the fuel directly (the manufacturers were forced to meet) is because the EPA set an ultimatum out there- no smoke, emissions, etc... The ECM takes a read on the throttle position (what you want) and then injects just the right amount of fuel to make things go with the available air supply.



In the old days of hard throttle cables, we hit the go pedal, dumped the fuel, and waited for the air supply to catch up. Result was all that black smoke that has given our favorite motors the "black eye". Smoke is our evil doer, and smoke is not a good thing regardless of one's penchant for wanting to see smoke.



I for one, am extremely pleased that the idle speed is controlled by the ECM. I haven't accidentally stalled an engine for so long I can't remember when the last time was. My starters are a lot happier too and live long lives now. Older is not neccessarily better.



And I don't miss the smoke at all, it is hard on my lungs and sinuses.

 

[rbattelle]

Oh, you're talking about drive-by-wire? Since these engines are electronically controlled using solenoid-activated fuel injectors, what other option is there except drive-by-wire. This isn't your dad's 67 'vette... there is no butterfly plate to move. In fact, there is no throttle at all. Remember that fuel flow in a diesel is not a function of air flow, so the concept of throttling the inlet air is meaningless.

 

[PHX ATC]

Older is not neccessarily better.

I can't believe you said that!



I actually like the fly-by-wire feel. It's the cool, bling bling factor, I think. :-laf

 

[Blakers]

The idle governor is great! Just like driving a tractor - it gives itself fuel to compensate for the load, even if your foot is off the pedal.



Makes anything else you drive bad though... I stalled my friend's car 3 times turning it around in the driveway.



Blake

 

[jarmar]

I find myself in agreement with Gbrady. With a load and a steep uphill start auto start can be helpful, but there are times with the truck will lurch ahead when I don't want it too. I wish this were optional.



jr

 

[Gbrady]

It does not matter if the speed is controlled by wire or cable. You should be able to operate at a safe speed for the conditions. My Dodge does not. When backing up with a light trailer my truck revs up from 1800 to 2000 rpm and will not settle down for about 15 feet or so. With a heavy trailer the speed will not settle down. Pumping the clutch to control your speed is a poor method at best. The computor programming should allow you to safely operate your truck no matter what the condtions. If it is designed that way it needs to be corrected. The Fords I have and a Chevy that I drive on oaccasion do not have this problem. Dodge simply needs to fine tune the programming to allow the driver to safely control the truck speed to the conditions. If they do not I am sure you will be hearing about them in tne news. I did have my truck checked by Dodge and they say it is operating as designed. That does not mean it is properly designed. It has been my only complaint on an other wise fine truck.



Best regards,

Gary Brady

 

[CChase]

When backing up with a light trailer my truck revs up from 1800 to 2000 rpm and will not settle down for about 15 feet or so.

That doesn't sound right. Mine will sit and idle along towing my 3K boat or 8k excavator. It doesn't care. Just hums along around 800 RPM. If yours is ramping up to 2,000 RPM, sounds like there is something wrong with your truck (or mine, but if it's mine I'll leave it as is).

 

[jarmar]

... revs up from 1800 to 2000 rpm and will not settle down for about 15 feet or so... .

Mine never goes over 1000, but when you are wanting to go very slow that is enough to make things happen too fast. Often it will slow down and surge to 1000 rpm. I don't think 1800 to 2000 is normal.



jr

 

[DPelletier]

I was confused as heck as to what the concern was until I read your second post. If your truck revs over 800 rpm whilst your driving it WITHOUT you pushing on the pedal, its broken. Period. Not normal.

Probably the APPS.

Find yourself another service department.



Dave

 

[John - K5AWO]

You should be able to operate at a safe speed for the conditions. My Dodge does not. When backing up with a light trailer my truck revs up from 1800 to 2000 rpm and will not settle down for about 15 feet or so.

Best regards,

Gary Brady

Gary,



There is definitely something wrong with your truck. I would suggest that if all grounds have been checked and cleaned including battery cables... . to disconnect the ECM cables and check for corrosion. Clean with a good electrical cleaner. Plug in and out a couple times to wipe contacts. Apply a little dielectric grease and put it back together. Same for the APPS sensor for the throttle control.



While cleaning the battery posts, leave power off the truck for a minimum of 45 minutes, key on.



On first power up/key on cycle, don't start it. Slowly press throttle to the floor and release slowly. Turn key off.



Then start and test the truck. Hopefully that will cure the beast.



I work on computers on fire trucks everyday. 90% of the problems encurred are cured by going through the procedure just outlined.



Luck to you,

John