Evap malfunction with no leaks
#1
Evap malfunction with no leaks
Hi all,
I have a 02 Caviler 2.2 with the famous P0440 evap malfunction.
I tested the system with a Solus scantool and found what I thought a sticky vent valve. Well that turn out to be the famous short harness problem. We went to the steelership and order one only to find out it only had one connector on it for $80. Well my friens threw a fit because he wanted both connectors and manage to get one out of them for the same price. Anyways the solus scantool controls the valve just fine everytime I shut it off and on. I then smoke the system and found no leaks (under 20 microns and inches of vac holds for over 20 min.
We are still getting the code. Does anyone know where and what to start testing next.
Thanks
Vinnie
I have a 02 Caviler 2.2 with the famous P0440 evap malfunction.
I tested the system with a Solus scantool and found what I thought a sticky vent valve. Well that turn out to be the famous short harness problem. We went to the steelership and order one only to find out it only had one connector on it for $80. Well my friens threw a fit because he wanted both connectors and manage to get one out of them for the same price. Anyways the solus scantool controls the valve just fine everytime I shut it off and on. I then smoke the system and found no leaks (under 20 microns and inches of vac holds for over 20 min.
We are still getting the code. Does anyone know where and what to start testing next.
Thanks
Vinnie
#2
Retired
Did you inspect the fuel cap o-ring?
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Retired Administrator
2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
Retired Administrator
2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
#3
Senior Member
True Car Nut
if it hold vacuum its not a leak, but 440 is the general "system control" code, which means could be alot of things. purge valve, canister, pressure sensor, etc
#4
#5
Retired
Sorry, it was just a thought. Last year, my 2002 S10 had the same code. Tracked it down to a rotted gas cap o-ring. Thus the reason I gave my 2 cents
__________________
Retired Administrator
2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
Retired Administrator
2002 *-10 5.7 V8
2023 Jeep Rubicon Diesel
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alesv (11-03-2013)
#6
Not sure about canister but if it was clogged i should get smoke out the filler tube. Or should I?
Is there a way to test FTPS?
Thanks for replying
#7
I'm glad your vehicle was only the the gas cap seal as these evap systems can be a PITA to fiqure out.
This one I'm working on I think is leading to something bad in the ECM.
I'll have to somehow test the FTPS or suck it up and just replace the part.
Thank you again for replying
#8
Senior Member
With the smoke machine I have had it not leak because your putting positive pressure on the EVAP system and it will only leak under vacuum. I have also seen a couple of bad fuel tank pressure sensor. I had one that showed vacuum even with the gas cap removed. Since you have a scanner the thing to do is fire the thing up, set the system to seal, activate the the purge solenoid until you have about 10 inches of mercury and see how fast it decays. If the vacuum dissipates rather fast you have a leak some place.
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WilliamE (05-07-2014)
#9
With the smoke machine I have had it not leak because your putting positive pressure on the EVAP system and it will only leak under vacuum. I have also seen a couple of bad fuel tank pressure sensor. I had one that showed vacuum even with the gas cap removed. Since you have a scanner the thing to do is fire the thing up, set the system to seal, activate the the purge solenoid until you have about 10 inches of mercury and see how fast it decays. If the vacuum dissipates rather fast you have a leak some place.
GM Fuel Tank Pressure Sensor Test - YouTube
GM Fuel Tank Pressure Sensor Test - YouTube
Ill be getting the car back in the near future so it will be awhile be I post back results or the solution.
Thanks for replying.
#10
Ok guys I know its been awhile but got it inspected with the one not ready. However it didnot cure his problem. now year later now its time for inspection he decides to bring the car back. So taking things from the beginning I did alot of test all componets were working FTPS had proper voltage and was fuxuating as pressure was applied. I decided to smoke the system from the gas cap side back and found that the filler tube is leaking severly. When I smoke it from the test port there were no leaks and no decay. So here my question Shouldn't the smoke reach the filler neck from the test port back? Or is his canister plug? My other though the smoke won't reach fileer tube from test port and the tank pressure never high enough during test cycle giving me a malfuction code instead of a leak code. I have the filler tube on order and when I get the car back Ill send smoke through the canister.
Sorry for the delay on what I found but I havent seen the car in a year LOL
Sorry for the delay on what I found but I havent seen the car in a year LOL