xtremely frustrated!! Diagnose Chevy doc!
 

I am back, and so is the continuous blazer problems. A 2001 Blazer xtreme 4.3L w/86K miles, Automatic is at it again. MAPsensor , TPS sensor, EGR valve, Plugs, Wires, Distributer cap, trans filter, air filter changed and all new. Cleaned throttle body, used gas additives and still no change. Had transmission looked at, fine and dandy. Problem--bogged acceleration, loss of power, goes great when the pedal is SLOWLY pressed, but when I give Jane some gas the thing sometimes just revs high up and no go, letting go slowly and she finally gets into gear and takes off. I have a new feul filter that needs to be put on, but can that make a difference? I noticed when I rev the engine it seems that air is not sucking in the throttle body like it should, well, there is a second hose attached to the side of the intake, a second air vacuum line, when I rev the engine it doesn´t change, i fugured there would be more air sucking when I did it. Can anyone diagnose??

RE: xtremely frustrated!! Diagnose Chevy doc!
 

from what you decribed about it reving up, it sounds like the trans is slipping, what does that have to do with the engine?

RE: xtremely frustrated!! Diagnose Chevy doc!
 

But I had the trans checked and tested, it passed. Its more of a power thing, I mean, the gears won´t shift unless there is enough power and timing for everything to correlate with each other right?

RE: xtremely frustrated!! Diagnose Chevy doc!
 

a bad 02 sensor could make your car loose power, are there any codes? is there a check engine light on?

*combining consecutive posts*

see link

http://www.mr2.com/TEXT/O2_Sensor.html

there are many reasons your engine can be running sluggish, bad ECM to timing, its hard to determine on a blog though


*EDIT: swartlkk* - combining consecutive posts. Please edit your post if you have additional information to add before another member has replied.

RE: xtremely frustrated!! Diagnose Chevy doc!
 

I would check and make sure the trany fluid cooler isn't clogged. I found out the hard (and expensive way) that when the cooler is plugged, the fluid doesn't move and subsequently the transmission doesn't either. If you get a big enough plug in there it will sieze up as though someone threw the truck into P going 20mph.

RE: xtremely frustrated!! Diagnose Chevy doc!
 

Nope, o2 sensors are good too, no codes. Trans fluid and filter was changed 1 year ago. Its wierd, today it was running great, 100%, then tomorrow it could run 65% again, but when it runs 65% lacking power, the heater doesn´t heat, I have no idea whats going on. Can a bad fuel filter cause intermittent power loss like that?

RE: xtremely frustrated!! Diagnose Chevy doc!
 

Possible you have an intermittent wiring issue check all the grounds and power connections etc. Check the PCM/ECM connections, fuse block etc...check the ground under the battery box and air box etc.. If you are not getting proper ground contact somewhere then that could send resistance into the circuit and mess things up. But since it don't happen all the time you take it to the dealer and they don't find it....

I hate intermittent problems because you never carry a scan tool to store freezeframe data 24/7 that would be one way to find this problem....

RE: xtremely frustrated!! Diagnose Chevy doc!
 

your right! I hate intermittent problems too. But as far as a chevy dealer here in Germany, ha! I will post and see how the fuel filter changes things...seems to me I need something else to help my blazer run like a champ.

RE: xtremely frustrated!! Diagnose Chevy doc!
 

How is the fuel pressure at the "shrader valve" (small tire valve looking thing by the firewall near the back of the intake on drivers side) it should be about 60psi normal idle if it is less than that at times then you either have a loose wire at the fuel pump or the pump is getting tired....

RE: xtremely frustrated!! Diagnose Chevy doc!
 

hmm, I didn´t know the fuel pump can not work up to 100%, I always thought that if they don´t work they quit altogether. Last time I had the pressure checked it was like at 56psi. But the pressure dropped when giving alittle gas, can this be a fuel filter problem too?