Hey, I did all the tests that our friend George told me to do... unfortunately I didn’t find the defect, there’s no false air intake, (or I don’t know if I did it on all the car’s vacuum hoses) I just did it on hoses that come out of the hood ball... for me they are the only vacuum hoses... or am I wrong?! The TPS sensor, the values ​​between the scanner and the accelerator make sense and my fuel trims at idle is negative (0.0% to -3.0% only) the only thing I found is that when I repeatedly step on the brake at 1000 rpm, jumps to 1400...

I don't know what else it might be, one thing I noticed is that when I was doing the tests at 2500 rpm as George told me... my cylinder ignition advance is -30 ° I don't know if this is normal!

 

So your idle changes significantly when you step on the brakes?

What are your 4 fuel trim numbers at idle and again at 2500 rpm? LT1, ST1, LT2 and ST2.

George

 

and what happens to fuel trims when you step on the brakes out of gear at idle?

George

 

Hey guys, especially George, I have good news, I was researching right here on the forum and they said about a screw in the throttle body... I thought to myself, let's try... why not? I adjusted it a little and immediately the car idle jumped from 1000 rpm to 500-600 rpm, I think that solved the problem right?! But I think I have a vacuum problem in the brake system...

So let it be noted, if your Blazer has the same symptoms as mine, check the screw on the throttle body, if it doesn't resolve do what George said...

First picture in idle

 

Me and her (Blazer), we can only thank the forum, especially George, we are very grateful for you, she is back to normal, of course she is not 100% but little by little we will improve what is not good, the next one to be done are the brake system, again, thank you very much!

Some pics