problem and what fixed it

AFter new Ign mod and crank sensor, my 2.5 ran fine for 4 days, still had just a slight fluctuation at idle. Had a bit of trouble of stalling when putting into gear when not all the way warmed up, but wasnt bad.
Then on Friday after a decent cold start and a 25 mile drive, first time i stopped and put it in park, engine rpm's jumped up to what would have to be 2500 (no tach) But when you would put it back in gear, idle was normal, it wasnt the engine load holding it back either, it would actually idle slow as it should, back in park, fast again. In gear, fine as can be, i thought this was so weird because how can a tranny make the rpms drop back to normal???
Anyway, when i got home i check was was just the oter day "cleared codes" and it had a new one. A code 34. MAP sensor reading low" or some thing to that effect. Bought one, cleared codes, ran the car, idles perfect in and out of gear, cold starts good, no stalling...
Just wanted to post this if someone else has the same weird "tranny in gear idles ok" that this thing was doing.

AFter new Ign mod and crank sensor, my 2.5 ran fine for 4 days, still had just a slight fluctuation at idle. Had a bit of trouble of stalling when putting into gear when not all the way warmed up, but wasnt bad.
Then on Friday after a decent cold start and a 25 mile drive, first time i stopped and put it in park, engine rpm's jumped up to what would have to be 2500 (no tach) But when you would put it back in gear, idle was normal, it wasnt the engine load holding it back either, it would actually idle slow as it should, back in park, fast again. In gear, fine as can be, i thought this was so weird because how can a tranny make the rpms drop back to normal???
Anyway, when i got home i check was was just the oter day "cleared codes" and it had a new one. A code 34. MAP sensor reading low" or some thing to that effect. Bought one, cleared codes, ran the car, idles perfect in and out of gear, cold starts good, no stalling...
Just wanted to post this if someone else has the same weird "tranny in gear idles ok" that this thing was doing.

Appreciate that. Good to know. So often we rack our brains trying to help, and never find out if it helped, or we were totally off track, or if it got fixed, anything. Good to have some feedback. Makes sense, the tranny's load changes the load on the engine, which in turn changes vacuum at idle, what the MAP is there to monitor.

Appreciate that. Good to know. So often we rack our brains trying to help, and never find out if it helped, or we were totally off track, or if it got fixed, anything. Good to have some feedback. Makes sense, the tranny's load changes the load on the engine, which in turn changes vacuum at idle, what the MAP is there to monitor.

Yes thats why i posted the fix, i searched and serched and never saw anyone ever say that putting in gear could "fix" a high idle, and only general on what a MAP does, how to test, but not what type of problems , least not this problem, first i have heard of it anyway.

Probably just needed an idle relearn or a sensor paramater learn, which calls for the car being in gear for a little bit

Probably just needed an idle relearn or a sensor paramater learn, which calls for the car being in gear for a little bit

No, you misunderstood, the idle "fix", was just a term i used with the old MAP to mean idle was fine in gear, but engine raced out of gear, The real fix came from a new MAP.

Ah, gotcha. I guess I need to read a bit slower XD