87 Accord DX w/carb
 

Hi!
Lately, when first started, the (cold 30-40F outside air) engine idles very roughly.
It will also miss fire occasionally. Just about the time when the thermostat opens,
the idle goes to 3500-3750 rpm by itself and will not come down for about 90 seconds
(until the engine is further warmed up). However, once the engine *fully* reaches
operating temperature, it runs and idles normally. If I turn off the engine before
it's fully warmed up, it will diesel (sputter-sputter) for 5-6 seconds before
stopping. It will crank but not start for 10-20 minutes if I try to immediately
restart it.

It's a mystery to me why it runs normally when at temperature, but has all these
problems when cold and is started.
Any suggestions appreciated.
Ken

Re: 87 Accord DX w/carb
 

On Tue, 21 Feb 2006 20:34:56 -0800, "KenA" <kabrahamsen@comcast.net>
wrote:
>It's a mystery to me why it runs normally when at temperature, but has all these
>problems when cold and is started.
>Any suggestions appreciated.

In primitive gasoline-powered vehicles before computerized ignition
and fuel injectors, this was more common than not!

I think it was an attempt to emulate the behavior of a horse in
similar circumstances ...

J.

Re: 87 Accord DX w/carb
 

KenA wrote:
>
> Hi!
> Lately, when first started, the (cold 30-40F outside air) engine idles
> very roughly. It will also miss fire occasionally. Just about the time
> when the thermostat opens, the idle goes to 3500-3750 rpm by itself and
> will not come down for about 90 seconds (until the engine is further
> warmed up). However, once the engine *fully* reaches operating
> temperature, it runs and idles normally. If I turn off the engine before
> it's fully warmed up, it will diesel (sputter-sputter) for 5-6 seconds
> before stopping. It will crank but not start for 10-20 minutes if I try
> to immediately restart it.
>
> It's a mystery to me why it runs normally when at temperature, but has
> all these problems when cold and is started.
> Any suggestions appreciated.
> Ken

Check the intake air preheating system. With regards to the first item, in
cold weather a bimetal spring in the air cleaner housing shunts vacuum to a
vacuum diaphragm allowing warm air heated from the exhaust manifold to enter
the air cleaner. This warm air system is necessary to prevent the
carburetor from icing up during cold damp weather. You will also want to
check the operation of the choke. The linkage could be sticking or there
could be other problems. One such problem could be the choke heater cap
gasket. Please see my earlier post at http://tinyurl.com/o7ape.

Eric

Re: 87 Accord DX w/carb
 

Does it have trouble kicking down to its normal idle speed? I have an '88
Accord that had that problem and I eventually tracked it down to a faulty
Frequency Valve C. It's a very common problem.

I wasn't sure if you were suffering from this problem but I thought I'd throw
it out there anyway

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