Surging Due to Dashpot - Possible Solution

[Thomas_Magnum_'98]

Hello all. So I bought my 1999 5 spd about a year ago, and ever since then I've had this issue where if the truck is in lower gears (1st and 2nd), the truck will lurch like the brakes are being applied when the gas pedal is released. Now, this issue was due to the Dashpot not "softening" the closing of the throttle valve, but when the throttle adjustment screw was adjusted to alleviate the problem, the engine would idle in the 1700 - 2000 RPM range. I adjusted it back and the surge reappeared and I hadn't messed with it since, thinking the only solution was a new throttle body spring (which can't be bought separately from the $500 throttle body). However, recently I had an idea. That idea is pictured below:

Now, I know this looks janky, but it seems to be doing the trick by "helping" the throttle spring and allowing the dashpot to be adjusted correctly. The design consists of a spring from Home Depot, a zip tie, and a length of paracord. Thoughts, criticisms, ideas? Any long term detrimental effects? Let me know what you guys think! [emoji106]

 

[bentos1]

That sure is "Janky", but it seems to be working.
Would you not be able to epoxy a small rubber piece to the dashpot. Or something soft to alleviate the throttle return.
There may some kerjiggering that you could do with the existing TB spring that could help. Although messing with that could potentially make things worse of course.

 

[Chuckles89]

Did you already do it or did you just find that picture somewhere? The post is a little confusing in that aspect.

Mine does that too, maybe I could try this out and see if it helps.

My dad had this done on his '89 4Runner for at least 200k miles and it was fine.

 

[BrandonF]

I also have the same problem. Only notice it while creeping in stop and go traffic in 1st and 2nd gears but it is kind of annoying.

 

[Thomas_Magnum_'98]

Sorry for the confusion. Yes. This is the setup I'm running right now. It seems to have helped significantly. I can post part numbers of the springs and packaging pics later too. I was just wondering if anyone else had done something like this. Apparently they have!

 

[Thomas_Magnum_'98]

Also, I would like to make this design a little cleaner. I was thinking a bike brake cable attached like the throttle cable with a spring in compression on the other end? I don't know if it would work any better, but it may look better!

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[gamefreakgc]

On my old 5 Speed I just went to the junkyard and took apart all the TB's and dashpots until I found one that worked like it should and bought it. :noidea:

I'd be afraid of that cord hanging up on something it's not supposed to and holding your throttle wide open.

 

[BrandonF]

On my old 5 Speed I just went to the junkyard and took apart all the TB's and dashpots until I found one that worked like it should and bought it. :noidea:

I'd be afraid of that cord hanging up on something it's not supposed to and holding your throttle wide open.

As unlikely as that is, I agree. The throttle body isnt something to jank out on.

If Toyota only sells full throttle bodies, has anyone managed to find a non-OEM replacement for the dashpot?

 

[Thomas_Magnum_'98]

Problem is, it's not actually an issue with the Dashpot. It's an issue with the throttle body spring being weak. The only way to get a throttle spring is to buy the throttle body...

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