Was driving my 88 AE92 4afc today and was going up a hill and when i was going to gear down for a light i noticed that the car was jerking and surging on trailing throttle. i put the clutch in after realizing this and noticed that the car was idleing at 2000rpm. I pulled off the road to check under the hood and looked around and saw that a vac hose coming off what i think is the high altatude filter box thing. After puting the vac hose back on it made no difference. I decided to get home as soon as possible and drove for about half an hour then i noticed the car was driving perfectly again. I was on a mountain a fair ways above sealevel. I drove to a friends house and checked everything againg and headed home. 10 minutes later it was doing the same thing again. just got home half and hour ago and am writing this post.

 

Anyone have any idea as to what could be going on?

Thanks.

so after more looking around in the engine i took the air intake off and looked down the carb and saw what looked like a little rock stuck in the bottom butterfly valve proping it open slightly.

Using a long screwdriver i attempted to un-lodge the rock. i could barly even open the valve using the end of the screwdriver but the rock did move slightly, but now the car idles between 2 and 3.2k making it very difficult to drive. Any suggestions as to how i might get this rock out?

Thanks.

Well.. is it a little rock and how did it get past the airfilter??

 

If it is, then you have a problem... you must not let the rock get into a cylinder!

 

How about finding a length of hose that will fit down the carb, maybe 5 or 6mm diam, and tape it to a vacuum cleaner- it will hopefully suck the rock onto it an lift it out.

 

Another one would be to hook a compressor up to the spark plug hole of whichever cylinder has the inlet valve wide open and see if you can blow the rock back out.

 

If not, take the carb off and do it.

 

If it is a rock, I'm amazed it hasn't dropped down into the intake manifold as you drove the car and opened/closed the throttle.