'79 5 speed stalling problem

[Rupesy]

The last few times I drove my car, it started and ran great for a while and then would develop some stuttering problems. Not real major, but annoying and maybe signaling me there is another issue. Always, on a cold start it ran without any stutter. Usually I leave my house and hit the highway for about 10 minutes and when I came off the highway and began putting around town I noticed the issue. It would idle a little rough, however, it would stutter between 1000 and 2000 rpms and then go away above those rpms and run fine. I figured maybe some bad gas or dirty injectors so I added some injector cleaner a few times and last night decided to try some Seafoam through the vacuum. I had a friend who ran it through his 928 and said he had some good results. I added it per instructions and it seemed to be working as it stated on the bottle. The car idled great and I did not notice any issues. This morning I started it as usual and it fired right up and ran beautifully. About 5 minutes down the road I was shifting between 4-5 and the car stalled in between shifts. Idle dropped like a brick. As soon as I released the clutch the car started and ran fine. I proceeded to enter the highway because I figured it might work itself out. I noticed that the car still wanted to stall between shifts. I came of the exit in the next town and came to a stop and it stalled. If I caught it in time, I could keep it idling by revving the motor and keeping my foot on the pedal. The second I back my foot off, it would stall. I could not get it started once it quit. I tried starting without depressing the pedal and with depressing the pedal. I checked all my vacuum lines and they are all connected. I was able to clutch start it, but it wasn’t easy. If I got up enough speed, it would just barely run and then I put the pedal to the floor and it would start to go. Once again no power or issues running down the road till I got home only to stall immediately in the driveway. I had to head to work so I really didn’t have a chance to check anything. Did not notice any white or black smoke from the exhaust either.

Any ideas on where to start when I get home?

[aluminum]

In Order :
Clean all the Grounds under hood and battery
Clean all the fuses / and the Relay " Plug in posts " . ( Pass side foot well )
Fuel Pressure regulator's ( look for signs of leakage ) bad Vacuum lines > test they for proper operation . ( the regulator's )
14 pin connector ( Pass side fender panel next to jump post )
check for loose Ignition switch on back side ( screw comes loose )

[Pete R]

+1 on the vacume lines. I would bet something is leaking. When was your last tune up? Cap rotor plugs ect?

[Rupesy]

Well, that wasn't too bad. Got home and took off the air cleaner to start looking around. The gasket between the air cleaner and the air flow sensor plate got partially sucked into the flow plate and lodged it open a little changing the mixture. It is an area that I need to work on since the air cleaner doesn't sit right on this area anyway. Thanks for the input!

[aluminum]

sort of a dental cleaning then ha ha glad u got it fixed