Where is the Decel Valve

Jcon · 06-15-2002, 11:36 AM

If I'm in stop and go traffic and the engine gets hot the car stalls when I push in the clutch. Or if I run the car and park it for 10 minutes or so and the compartment gets hot it stalls when I push in the clutch. It corrects itself as soon as I get some air ciculating back there and cool things down.

Anyway from searching the archives it sounds like the decel valve..I looked up a picture in the diagram section...but i can't locate it . Any hints??

stormcrow · stormcrow's Garage

Something wierd is going on here. When you push in the clutch, you take some of the load off the engine - it doesn't make sense that the engine should stall when you do this.

The decel valve is on the left side of the engine compartment just to the right of the heater blower fan - it has a screw coming out the top of it.

My engine increases in rpm when it gets warmer (78 sc targa) you may have a problem elswhere.

Steve

Jcon · 06-15-2002, 01:16 PM

Thanks

I probably didn't describe the problem properly. I was talking about when I lift off the gas and then push in the clutch to shift or brake. The RPMs drop rather rapidly and pass the 950 idle zone and stalls or sometimes catches at 200 RPM and comes back up. Again only when the engine bay gets hot. Once I get air flowing again things work fine.

Rich L · 06-15-2002, 01:42 PM

There are two types of decel valves (or vacuum limiter), the cylinder type and the saucer type:

Decel valve link

Jcon · 06-15-2002, 03:22 PM

Thanks

I was just coming back to the computer with my tail between my legs because I couldn't find anything on the left hand side.

Back to the garage.

It also nice to see that many smart people as confused as me on the subject.

stlrj · 06-16-2002, 12:10 AM

On an '81 the decel valve is located on the right side of the engine that looks like a UFO tilted on its edge with a small vacuum line attatched along with two larger hoses.

The vacuum line on yours may have cracked or come loose.

Joe

Sunroof · 06-17-2002, 06:12 AM

Jeff..

Same thing happened to me, especially coming off the interstate on the exit ramp. Low RPMs to almost stalling. It was not the decel valve but my mixture setting. On my 73 2.4 their is a hose coming off the decel unit to the distributor. After adjusting it did not help the problem! Check your fuel mixture setting.

Regards
Bob
73.5 T