Pulsing idle, trans not firm!!
 

Alright so i got a new problem with my blazer. I think it might be the MAP sensor flaking out but this is what is happening.

When the car is cold and isnt warmed up the idle pulses quite a bit, but not to the point till it wants to die out/ stall. Along with the pulsing idle the trans doenst seem to be as firm as normal. All these problems seem to go away when the car is finally warmed up.

ANY IDEAS?? MAP SENSOR???

[IMG]local://upfiles/2158/F292DCB578FE4F978FA109C7B514AD5C.jpg[/IMG]

RE: Pulsing idle, trans not firm!!
 

What vehicle are we talking about here. I mean, I know it's a Blazer, but how about a year, drivetrain config, etc...

With that said, it may be time to remove your throttle body and give it a good cleaning. Sounds much like a sticking IAC valve (controls idle).

Also, now that it's getting colder out, the trans may not have the lightning quick (*sarcasm*) shifts that it has when its warmer due to the viscosity change in the trans fluid. Doesn't rule out a possible problem, but... Is the transmission slipping or just not shifting as quickly as you remember?

RE: Pulsing idle, trans not firm!!
 

It is a 1995 blazer with 4x4. It doenst seem to be slipping just not as firm as i thought. That is a good point that the cold weahter would change that. I will clean the TB and see what happens. I already replaced the IACvalve