I have a 1996 SLS with about 86K on it.
Ok *sigh* My error codes were P0300 (Engine misfire) and P1406 (EGR Valve Pintle Position Circuit). Bear with me guys...I'm a rookie. So I changed the plugs out using the ACDelco platinums, plug wires were only about a year old and still in great condition, threw in a new air filter and - hahahaha - that I was going to clean my EGR. The P0300 code was cleared, so I guess the plug change took care of it? But I'm still getting the P1406.
Here's what my car is doing: When I get in to start it up in the morning - when I havent driven it in 8 or more hours - it starts fine. If I drive it anywhere and turn it off and leave it sitting for more than 5 minutes, when I try to start it again, the ignition is turning over (think ja-ja-ja-ja-ja-ja said real fast...thats the sound), but it takes a good 5 to 10 seconds to catch and start! Here's the kicker: If I get back in within 5 minutes of shutting it off, I can get back in and it starts up no problem. If I wait any longer than 5 minutes, I go through the whole ja-ja-ja-ja thing.
Ok, problem # 2: When I run it up a hill (unavoidable since I live on one), then come to a stop, putting the car in park, the idle goes crazy. It revs a little, then slows to almost sounding like it might die, then revs again, then slows again etc... a few times. Now wait, because if you read above, it does this revving/slowing thing right after it goes through the starting issue I'm talking about too. I havent noticed that it does this when I'm still in gear (like being at a light after coming up a hill). Pretty much just in park I think.
It seems to me that it might be connected.
One last thing: (and you thought I was done!) When I accelerate (only when cold) alot at once, SOMETIMES it hesitates before it accelerates...but not always.
I really need help! Could all this be related to one particular issue? I'm so frustrated!! Any help would be sincerely appreciated.