Engine/Transmission (1998.5 - 2002) Bump at startup

[Hobart]

I sometimes feel a slight bump when starting up at a light /stop sign ?

 

[fest3er]

I quickly thought of several wisecracks to make (ala Engvoll and Foxworthy, and even one that would make Mrs. Robin blush and get me kicked out of here forever). Instead, I decided it'd be best just to gently prod you for more information about your vehicle and the symptom.

 

[Hobart]

Yes the Q is a bit vague. Seems like a slight delay between stepping on the accelerator and taking off with a little bit of a bump felt in the seat of the pants. First noticed it when I had my camper off for a short while. 75K on the truck over all. No other problems I'm aware of. Seems to happen only in town??

 

[fest3er]

Ah. A delay between operator action and vehicle response. Play with it some more. Depress the pedal *really* slowly. See if there is any repeatable--meaning either it does the same thing every time or it does the same thing whenever the delay happens--correlation between pedal position and reaction. If so, you might have a faulty APPS (acc. pedal pos. sensor); cleaning the APPS with a decent spray contact cleaner might clear it. Radio Shack might sell such a cleaner. CDC makes a contact cleaner, too. Beyond this, your truck's got the could-be's.

 

[Hobart]

Did a test run today tried every which way to get that "bump"?????The only thing I didn't do was take it for an hour long highway drive and then go into town, will try that next week.

 

[Joe Mc]

Possibly the drive shaft slip joint is dry? Had a similar thing happen to me, you'd come to a stop - the rear suspension lifts, slip joint gets a tad longer, then you stop and it's tight - take your foot off brake and onto go pedal - "pop" it frees back up. This was on a small Toyo-Dah it was so light you could feel everything like a pea under the mattress. With our trucks you don't feel things as much because they're so heavy (super padded mattress). It's worth a shot and cheaper than the APPS.