1998 Chevrolet Blazer EVAP code problem

Tiny
CHIEFCATCHEMALL
  • MEMBER
  • 1998 CHEVROLET BLAZER
  • 4.3L
  • V6
  • 4WD
  • AUTOMATIC
  • 130,000 MILES
Hello. My 98 blazer is setting off Evap code number P0440, which indicates an Evap emission control system malfunction. Now here comes the interesting part. When I shut off my vehicle my fuel pump stays on about 3-4 seconds longer than it should. Now, I would like to believe these two problems are somehow related. What would be your guys best guess at what is causing this? I know how tricky Evap leaks can be without a smoke test. But I was hoping with the fuel pump staying on longer than it should after shutdown of the vehicle it would be a dead give away to a knowledgeable mechanic. Also I had the fuel pump replaced approx. 3 years ago. Thanks in advance! -Andrew
Saturday, November 23rd, 2013 AT 9:50 AM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,144 POSTS
This code indicates that a part of the EVAP control system is no longer fuctioning correctly. Thus, I don't see how it is related to the pump running. (Not saying it isn't possible)

Have you done the following? Check to make sure gas cap is good? Inspect the EVAP system to make sure there are no cuts or holes in the hoses? Any disconnected hoses near or around the purge solenoid? Check purge solenoid?
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Monday, November 25th, 2013 AT 8:43 AM
Tiny
CHIEFCATCHEMALL
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  • 17 POSTS
Now correct me if I am wrong. Doesn't NY allow for one pending I/M monitor to be incomplete during inspection as long as my CEL isn't on? From what I have gathered the Evap monitor only tests when the fuel system is between 15-85% full. So what if I fill my tank and then turn off the Evap code and then drive it for a while ( keeping the tank at least 85% full the entire time?) Won't this show that the car has went through the drive cycle and not set off the Evap code allowing it for to pass inspection?
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Monday, November 25th, 2013 AT 12:24 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,144 POSTS
I have to be honest, I'm in PA and am not sure of the specifics when it comes to emissions testing in NY. However, your theory may work. But, I do believe the EVAP monitor works regardless of the amount of fuel in the tank.
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Monday, November 25th, 2013 AT 5:20 PM

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