Hope ya'll can offer some advice. My '91 964 3.6l baby is starting to stall when coming to a stop. I then have to wait at least 30 seconds before restarting. Seems to get worse as the engine warms up.

I'm thinking it may have something to do with a temperature sensor that helps control air intake. Any thoughts are greatly appreciated.

 

Any other symptoms? Stuttering? Misfires?

 

Did you have the battery disconnected for any length of time?

 

My car would stall when the DME relay was going bad......

 

Clean the ISV first. It's free.

 

Worse when the engine really hot (i.e. if yes, do you know that both the oil cooler fan low and high speeds operate)?

Cold running ok? DME fuel relay swapped over yet? Rough idling (ISV)?

 

No other symptoms noted.

 

Excuse my ignorance but what is an ISV and where can I find it on the car? I found a thread in the 928 forum about spraying WD40 into it but nothing to help me locate this ISV in my 964.

I'm hopeful this is the problem as the fellow in the 928 forum was stating the exact same symptoms that I'm experiencing.

 

Not sure about really hot but may likely be the case since it seems to occasionally stall when first starting out but then stalls on every stop after more time has elapsed. Really scary when I'm on the interstate with stop and go traffic. People behind me get quite upset when it stalls and I have to sit for 30 sec or more. Plus, I have to be sure not to try and start it before it's ready or I just keep delaying when it will start.

Thanks for these suggestions. I'll research this more after I find out where the ISV is located and clean it, since that sounds quick and easy.

 

Battery was not disconnected.

 

It sits on top of the engine. Silver cylinders with two hose connections and one electrical connection. It's easy to get to.

Search for a picture of the engine bay on this forum and download the service manual. That will help you.

 

I would check your Fuel Pressure Regulator.

 

Ok, found the ISV, thanks. Could not find, via search, a service manual, though. Do you have a link?

Also, the two hoses are attached with crimp on clamps. I'm going to try and pry them off with a screwdrivef and reclamp them but will probably have to cut them off. Then I'll have to figure out the diameter for a replacement clamp.

So, it was easy for me to find ISV but not so easy for me to remove it. I'm just a novice though.

 

100% Fuel pressure regulator. I went through this exact same thing. Not anything easy to look at to determine if it’s working correctly. I replaced mine and it was exactly why after my car stalled and wouldn’t start again. The FPR is supposed to pull the fuel back when the car stops running and instead fuel was being dumped into the engine. It was like the car was flooded and it wouldn’t start. 30 seconds or so later it would start. Pretty annoying at a stop sign with cars behind me!

 

I had similar symptoms and my problem turned out to be the camshaft position sensor.