My girl has a 1998 4 door blazer that has a P0440 (EVAP) error. I am not new to the automotive world, but new to the blazer. I know the code is saying that is was unable to create a vaccum. I get under the car and look.. frist thing i find is that the vapor canister purge valve was shot.. cracked and rusted. I replaced that and checked all the wiring to it. Drove a few hundred miles the light comes back on same code. Try number 2. I get back under the car and look more closly to things. I find that ALL the lines to the evap system that run along the frame are well dust. So I head back to the stor and pick up 30 feet of 5/16 fuel line a "T" and 8 hose clamps.

Ok now for what i did. i removed ALL the stock lines and connectors. I took the hose and went from the Vapor Canister Purge Solenoid in the engine bay all the way back to the vapor canister the upper most connecter on the canister itself, and clamped it all down nice and tight. Then I took a line from the lower connector on the vapor canister ran it to a "T" splitter and tighted that down tight. From the "T" i ran one line to the Fuel tank vent valve (on the top of the tank towards the front) and made sure everything was nice and tight. from the last spot on the "T" i ran a line to the middle line on the rear of the tank.

about 200 miles the light comes back on.. same code... What else can it be? I am at a loss here... The ONLY thing on teh whole evap syatem i didnt replace was the Vapor Canister Purge Solenoid, Fuel Tank Pressure Sensor, and the Vapor canister itself.

What would you guys reccomend looking at next? My guess is the fuel pressure sensor... but dumb question... Where is it located on this damn car???

like i said i removed all the stock lines and connectors. Are there any special valves built inside or any other reason regular fuel line wouldnt work??

Sorry for the 100's of typos, run on sentences and mispelling of words.

Here are the diagrams I used. Thanks for any Help Guys.

http://www.gmpartsgiant.com/componen...m30t10506.html

http://www.gmpartsgiant.com/componen...m30t10506.html

 

BuMp.. need some advice inspection has been up for 2 weeks now, and would liek to tackle this issue this weekend. Any help would be much appreciated. Thank you.

 

gas cap seal good?

 

A quick search for "P0440" should turn up a number of threads on this code with what has worked for others. It will also turn up the OBD2 diagnostic sheet.

 

Yes the gas cap is new. Also I did do a search and read everything on this site about 0440 0441 and 0442. I was more or less worndering if what i did (replaced the lines with fuel lines and bypassed all the stock connectors) was an ok solution and not part of the problem. Also the location of the Fuel Tank Pressure Sensor (couldnt find it on the site sorry).

EDIT:::: Found the location of the FTP Sensor.. Thanks ALL will try this next. Also I think the Tank Vent may be loose, as stated in some other threads it is supposed to point to the front, so i will check that too. Thanks again