I live in canada, and have a 99 blazer LT that has been nothing but a curse to me. i replaced the tranny a couple of months ago, drove it a week, then the intake gaskets went. replaced them, drove it a week and now I am having more problems. past couple of weeks when i first start it seems to run fine but when i put it into gear it runs really loud and runs rough at approx. 600RPM and it shakes the whole thing.it does this until the engine has been warm for about 1/2an hour. the symptoms seem to go away once i put gas to it or have it in park. could it be just the fact that it's so figgin cold?

 

Is the check engine light on? If so, have you had the codes read?

What have you done to try to cure the condition? Have you cleaned the throttle body? Specifically the IAC (idle air control) valve and its passage?

 

I ran the code reader andi just get the emissions pinhole leak code. That is unchanged from when i first got the blazer three months ago. other than that it is just the repairs stated above. it ran fine after i did the intake gaskets but only for about 3 weeks.

Btw code is p0442. only code on blazer. however there was some freeze frame data detected. i could not get a hold of it. will try later.

 

Why not start with a TB cleaning.

 

Definitely look at the Idle Air Control, also try putting some high test gasoline in it can
possibly narrow whats wrong down some.
And what about the Electronic Choke?

 

There is no electric choke. The newer motors (CPI & SCFI, maybe TBI too) meter air using the idle air control valve. The main throttle blade closes off completely with the exception of a small hole. The IAC valve controls the volume of air entering the motor.

 

Swartlkk: I cleaned out the TB when i redid the intake gaskets three weeks ago. It used to be so full of carbon and **** before that the throttle was sticking shut. I got it polished very clean and it stopped that problem. for the IAC, do i still use that TB cleaner?

 

Yes, you can use the same TB cleaner. Sucks that you did not clean this passage when you had the TB off prior.