Honda Car Forum

I have an '86 Prelude with the 1.8 dual carb engine. When I release the gas
pedal to shift the RPMs will usually rise a bit and then slowly come down,
sometimes the RPM just stays where it is for a second then drops. Why might
this be happening and what can I do to fix it? I would rather not be putting
that extra wear on the clutch and synchros, but waiting for the RPM to drop
to about where it would be in the next gear gets old real fast. Any ideas?

Cory

"Cory Dunkle" <cadnews@verizon.net>, being of unsound mind, did utter in
news:K8Srb.20263$y95.10052@nwrdny01.gnilink.net:

> I have an '86 Prelude with the 1.8 dual carb engine. When I release
> the gas pedal to shift the RPMs will usually rise a bit and then
> slowly come down, sometimes the RPM just stays where it is for a
> second then drops. Why might this be happening


Vacuum-operated emission control dashpot that holds the throttle open
briefly when you let up off the gas to shift. Common with carbs after about
1973.


> and what can I do to
> fix it?


Disconnect the damn thing. A real PITA they are.

Look for a round, diaphragm-looking thing with a vacuuum hose going to it
and with a bracket and screw impinging upon the throttle linkage. Be aware
that if you have to go for emissions tests once in a while, you'll need to
reconnect it before being tested. Also understand that if you have state
enviro-Nazis patrolling your roads, they take a very dim view of
disconnected smog shit. You can also just back off the adjusting screw
until it does not touch the bracket and thus does not hold the throttle
open. This method is not obvious to the eye and will be easier to get away
with.

--
TeGGeR®

"Tegger®" <teggeratistopdotcom@changetheobvious.invalid> wrote in message
news:Xns942FC0414D82Eteggeratistop@66.11.168.195.. .
> "Cory Dunkle" <cadnews@verizon.net>, being of unsound mind, did utter in
> news:K8Srb.20263$y95.10052@nwrdny01.gnilink.net:
>
> > I have an '86 Prelude with the 1.8 dual carb engine. When I release
> > the gas pedal to shift the RPMs will usually rise a bit and then
> > slowly come down, sometimes the RPM just stays where it is for a
> > second then drops. Why might this be happening
>
>
> Vacuum-operated emission control dashpot that holds the throttle open
> briefly when you let up off the gas to shift. Common with carbs after
about
> 1973.

Blech. I'm used to my '60s Fords which pretty much everything is manual or a
very straightforward linkage/design/adjustment. Also, the only emissions
controls are PCV valves, which help keep the engine clean.

> > and what can I do to
> > fix it?
>
>
> Disconnect the damn thing. A real PITA they are.
>
> Look for a round, diaphragm-looking thing with a vacuuum hose going to it
> and with a bracket and screw impinging upon the throttle linkage. Be aware
> that if you have to go for emissions tests once in a while, you'll need to
> reconnect it before being tested. Also understand that if you have state
> enviro-Nazis patrolling your roads, they take a very dim view of
> disconnected smog shit. You can also just back off the adjusting screw
> until it does not touch the bracket and thus does not hold the throttle
> open. This method is not obvious to the eye and will be easier to get away
> with.

It's very tight in the area around the carbs (everywhere really) but I will
look for such a thing and disconnect it. I would much prefer the car to
behave like a normal engine. If I wanted the RPM to stay up after I let off
the gas I wouldn't have let off the gas, now would I? Well hopefully I can
fix that.