Canister purge valve diagram needed

Hi,

The purge valve is part of the EVAP emissions system (EVAP). It is triggered to allow gas fumes to enter the engine from the EVAP canister (charcoal canister).

It functions on both electric and vacuum, either of which can cause a code. Also, the purge valve itself can fail.

If you look below, the first two pics are the electrical portion of the purge valve circuit. I highlighted and placed red arrows to where power comes from and goes to. (Power from fuse/ground provided by PCM).

The last pic shows the vacuum portion of the system. Gas fumes from the fuel tank are stored in the charcoal canister. At a specific time, the PCM provides ground to actuate the purge valve. At that point, a vacuum from the throttle body draws the fumes through the valve from the canister to be burned in the combustion chamber.

If you have the code that was set, let me know what it is so I can point you in the right direction, vacuum or electrical.

I hope this helps. Let me know if you have other questions. If you have the chance, let me know what the fix was. I'm interested in knowing.

Take care,
Joe

See pics below. Note: Pics 1 and 2 came from a one-page schematic. I had to cut it in half the make it readable. I did overlap them so you can follow from one to the next. Also, sorry for the sloppy printing in pic 3. I can't do it neatly with a mouse. LOL

Yes, that helps a lot I just wished I had another Camaro with the 3.8l motor to physically see how its hooked up on someone else's vehicle.

Hi,

Which part do you need help with? I should be able to help.

Let me know.

Joe

Well, like how it's connected on another Camaro I might not have something connected unless it's the actual valve itself, but I took the engine apart, and rebuilt it. well in most factors and now it's misfiring and very rich, too lean, and one of the codes that popped up is for the evap canister.

When you say too rich, too lean, those are opposites. If it is too rich, suspect a fuel pressure issue or a leaking fuel injector. If it is too lean, a vacuum leak (such as the valve you asked about) low fuel pressure, or anything that can allow unmetered air to enter the engine.

Here is a link that shows how to locate a vacuum leak if you have a lean mixture:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Here is a link that explains how to test fuel pressure if it's lean or rich:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If there are other codes, let me know what they are. Also, let me know the code you found.

Take care,

Joe

Hey, you know that might be on the money. I replaced my MAP sensor with an after market one from AutoZone, and I remember when I replaced my MAF with one from autosome, it wouldn't stay started unless I kept my foot on the gas, once I got the original OEM, idled just fine. So, I know some of those sensors are sensitive, and I may have to have that MAP sensor OEM, can you give me a schematic or diagram of the MAP sensor, and TPA sensor location? because I changed them both, but forgot which one is which.

Hi,

I attached the entire powertrain management system schematic below. There were a total of three pages. I had to cut each page in half to make them readable for you, however, I did overlap them so you can follow from one to the next.

Additionally, I highlighted all wiring related to the MAP and TPS.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

I hope this helps. Let me know what you find, or if you have other questions.

Take care,

Joe

See pics below.

That is very helpful! Thank you very much. I'll keep you updated on my progress.

So here's what it does:
On a cold start in the morning after sitting all night it starts up quickly, but after it gets to operational temperature I'll cut it off then try to cut it back on, and it hesitates like it's out of gas, but while slowly turn over.

Hi,

When it starts, is there any smoke from the exhaust or odd smells?

Let me know.

Joe

Yea, I can smell exhaust and yes, some smoke too.

If the exhaust has a strong fuel smell and you are seeing gray or black smoke, chances are the fuel pressure is too high or you have an injector issue.

If possible, perform a fuel pressure test on the vehicle. Here is a link that shows how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

You will need a fuel pressure gauge, but most parts stores will lend one to you.

Try this and let me know the results.

Joe

I was thinking the same thing with my injectors. Does this vehicle have a fuel pressure regulator, and fuel pressure test port? If so, are there pictures of the locations?

Hi,

Yes, it has both. They are on the fuel rail. The regulator is vacuum operated. Before doing anything, remove the vacuum hose and inspect for evidence of fuel in it. The line should be dry.

Then proceed with the test. Remember, the system is always pressurized, so be careful I attached a pic below showing locations (sorry for the sloppy handwriting) and the manufacturer's specs for pressure.

Let me know what you find.

Take care,

Joe

See pics below.

Okay thanks, will do.

You are very welcome. Let me know what you find and what I can do to help.

Joe