Hi, new guy here and thanks for the forum. Last week I bought the above vehicle. Two days after, I had problems starting it. It would turn over fine but did not keep running. After trying the second or third time, it would pop/backfire and then be o.k. for the rest of the day. Every morning I was having the same thing, and today after the backfire/pop, the service engine light came on.

I just got back from Auto Zone and had it checked. It gave the code
P0455. The reading indicated a Large leak detected.

reading was: the ECM has deteced a large leak in the EVAP system during
a system monitor test.

Probable cause:
defective, loose or missing fuel cap
EVAP canister broke, hose crake or not connected
Purge or vent solenoid defective
Vacum leak at engine.

Of course, I went the cheap route and replace the gas cap. No Help.

Any ideas before I spend a fortune trying to elimante the problem?

Many thanks in advance....

 

My second post here. I will try to do better than my first post. After I re-read it, it did not make any sense even to me. I always did get confused and nervous when public speaking.


Anyway, I am not really sure what my starting problem is, but I was wondering if it was possible to remove and some how clean a EVAP
Canister. I don't want to waste 160.00 for something I am not sure is really broken.

Many thanks in advance....

 

why do you assume it's broken?

 

Someone has a thread "Cranks but won't start" I thought kyle (the admin here) had a link in his signature but I can't find it. I know it exists though.

As for ideas on your issue, check the vacuum leak!!! That will cause huge & odd issues. Easy way is to run the engine & spray brake cleaner over the vacuum lines. When the engine revs up you've found a leak. Aside from a visual inspection of the lines this will let you know where an issue is.
In my experience an EVAP canister code will not cause the engine to stall or not run. EVAP is emmisions & I've had a code for a while but it relates to exhaust emmisions, what a vehicle puts out as per EPA & or CARB etc. It should not stop your vehicle from running because it wouldn't pass CARB standards.

Again for vacuum leaks, if they look cracked or "weathered" they could be issues. Check around the dist., all around the manifold & the lines leading into the DS fenderwell by the brake booster. Mine are getting bad & the routing of them gives me shivers because the vacuum line that controls the cabin controls - heat up, down, vent, defrost etc heads into the fender well & into the cabin.

<edit> btw the cheap route would be vacuum lines... depending if you bought a locking gas cap or not.

 

Please see the original post. The blazer has a hard time starting in the morning, but after that there is no problem. This is one of the options of having something wrong with it, and I was just trying to plan ahead.

Many thanks to all who have replied.

 

The cap I bought was not a locking type. I will probably go ahead a replace all the vacum lines that I can reach anyway. Just bought the thing and have no idea of where it's been or how it has been treated.

Thanks for all the ideas....

 

Update on my posting. Installed new vacum hose's. The other's were pretty frayed and collasped at the carb. I un-hooked the battery overnight and the check engine light was gone.

I am still having the starting problem in the morning only, but this time
there is not backfire. Again, it starts great and runs great after first
starting.

Any suggestions???

Again,may thanks for all the help