hey guys' need help. i own a 97 blazer. fuel pump died replace it. also change the filter. and relay. ran good for a couple of day's then on the road it started to sputter then stall. good crank no fuel getting to carb notice fuel pump not kicking in. HOWEVER after about 1 1/2 hrs of sitting it will start. car is running good right now but my check eng light is on im worried any advice would be great

ps i was told there may be a broken fuel tank vent valve would this cause it to stall then restart later

 

First, you need to get the SES code read and let us know what it is. Second, do a fuel pressure test and report back.
There are other possibilities such as the ignition control module (ICM) could be bad, and the EGR valve or MAF sensor might need cleaning.

 

RRIDDLE3. thank you for your input. i had my buddy put it on his computer it's saying P0440 evap emissions control failure. he is saying it's a faulty gas cap replace it. check eng light still on.i will be doing the fuel pressure test this memorial weekend hopefully this code will narrow it down.

 

P0440 EXPLAINED

I've never had a bad seal on my gas cap cause a problem with performance.

 

I have a really similar problem. I have an 01 LT and sometimes on long trips, my blazer will seem to develop a deadspot in the throttle, where if I push it down past a certain point, I lose all power, and then in a couple of miles it just shuts off. The fuel pump has already been replaced twice within a year and I keep having the same problem. It seems to only happen during the summer so it might be heat triggered. The temp guage is never too high when it happens though. When it shuts off, it takes several hours to start again, but then it runs fine. It's also throwing the exact same code. I hate to spend the money to replace the pump again and have the problem be something else, considering it has already been replaced twice. Please let me know what you figure out, because I am stumped.

 

jhenry83
yeah i had the same problem as you on hot days. a sudden lost of power follow by stalling. only after sitting a hour or more. it would start. a mechanic told me the next time this happen to remove the fuel cap for a minute. car stalled i remove the cap car started ten minutes later not 1 hr the next day we drop the tank found the fuel tank vent valve was snap off this happen when me & my buddy two very amateur mechanics drop the tank the first time. snap it off big mistake $$$$$ i order a new fuel tank online $105 total. replace it no check engine light big test will be when it gets hot hopefully this solves my issue. as a wanna be mechanic i will never give advice but run this by whoever does your auto work see what they think

good luck
joe c

 

Would a '99 Blazer have a fuel vent valve on the tank? When I pulled my tank recently to change the fuel pump, I only saw the three lines to the pump,along with the filler hoses. I read of guys breaking this valve,and my truck is still having problems of not wanting to start now and then,that sound like this. Is there one I may have broken and not be aware of it?

 

yeah first thing do have a 2 door or 4 door. mine is a 4 door. fuel tanks are different. mine is long running under rear driver side seat. vent valve is on the opposite end from filler hose. if your is 2 door then this info might not help. but it sure sound like you got some kind of vapor lock going on there. i google 99 blazer fuel tanks came up with the round tanks only. could not find a vent valve on them. hopefully if you keep posting on this forum somebody might be able to help you more.

 

Joe C, thanks for the advice. I am going to try that next time it shuts off on me. Hopefully I can get this figured out because I don't want to keep throwing money away.

 

My 96 is doing the same thing. It will run for a few minutes then lose all power and die. I just replaced the fuel pump and drove it all winter with no problems. Now there's an evap code. I don't remember seeing a vent on it when I dropped the tank. Do the 2 doors not have one? I had my fuel pressure guage on it and it seems to lose more pressure the longer it runs until it eventually dies. Does this sound like a broken fuel tank vent valve?
Thanks