legacycentral bbs

I noticed that I started getting a code 35 after I took out my snorkus. I would get it consistantly. Since i've cleaned my IAC valve and tightened my belt I haven't seen the things come on at all.

Would the IAC affect the purge sensor?

Anyways, cleaning the IAC is a rather simple thing to do. Definately a thing that can be done before spending 70 bucks on a purge sensor and all the frustration of installing it. I may go ahead and replace mine sine I've already ordered it and it should be here in a day or two.

-Ryan

It's not a sensor; it's a solenoid. The ECU uses it to control purge. Vibration and heat slowly cause tiny cracks in the coil inside the solenoid, and when the ECU detects an open circuit it throws the code.

That being the case, I can't think of a good reason why cleaning the IAC valve and tightening the accessory belt would make code 35 go away except that maybe your engine is experiencing less vibration and so the intermittent fault doesn't show up or something.

The purge sensor is a piece of crap. I garantee you that either your knock sensor or purge valve WILL fail or has already in the life of the car. Most likely both.

I think part of the problem with the purge control solenoid is that it's mounted in a place where it's exposed to a lot of heat and vibration. The pressure exchange solenoid on turbos is almost identical to the purge control solenoid in construction but it's over on the strut tower and has a rubber cushion between its bracket and the strut tower, and I've never actually heard of a failed pressure exchange solenoid.

DLC, I, and some other people were talking about relocating the solenoid to make it last longer and to make it easier to service. Dave's car's solenoid is dead. I don't know if he's gotten around to trying it. In principle it should be pretty easy. For the plumbing, you just need some 1/8" vacuum hose to connect the canister to the solenoid and the solenoid to the throttle body. Then one end of the coil connects to switched +12v wherever it's convenient, and the other connects to the white-with-blue-stripe wire in the 16-pin square connector behind the battery.

Who cares, its only to remove the small amount of gasoline that vaporized. No effect on how the vehicle runs, you'd pollute the enviroment less by running 2 PSI more tire pressure.

ciper, can you quantify how small the quantity of raw hydrocarbons you'd be venting is? I'm curious.

Yes, with my nose!

I think time would be better spent finding an ALTERNATIVE valve if you really wanted to do this. It just so happens that I have 12 replacment valves of higher quality.......
They are all brand new too.

I'm serious... I suspect the increase in hydrocarbon pollution would be significant.

Like I said above, I don't think it's all the valve's fault. Placed somewhere more appropriate and properly insulated, the OEM valve ought to last as long as the car in my opinion.

How do you explain the vacuum on the tank when filling the fuel? There is not pressure pushing vaporized gasses into the canister unless you leave the car sitting for extended periods.

The vapors get adsorbed by the activated charcoal in the canister -- they don't need to be forced into it.

And even under lower-than-atmospheric pressure, gasoline evaporates. It's volatile stuff!

You missed the point.

The canister is open to outside air. If the tank is under NEGATIVE PRESSURE no fumes will escape, it has a one way valve.

What Im saying is that the canister is empty almost all the time.

I guess I'm not that familiar with how the setup works. I didn't know there was a check valve between the tank and the canister. Where is the valve?

I thought the fresh air opening at the bottom of the canister was just to allow the purge valve to suck fresh air through in order to fully clear out the canister. But, yeah, I can see that I'm missing something because the tank is sometimes under vacuum.

I understand your claim. I'm just wondering if you can back it up with any tests or measurements.

I have heard before that evaporative emissions accounted for something like a fifth of hydrocarbon emissisons back in the days of carburetors. If that's true, then with the lower hydrocarbon emissions of our engines it seems plausible to me that disabling the EVAP system could increase hydrocarbon emissions by 50% or more.

But I can't remember where I heard or read that.

I dont know. Its all from memory

Your right that when the valve opens it lets unmetered air pull through the canister.

haha, look what I started.

To answer your question, though, I didn't know if there was a connection. You could be right that the less vibrtion may be helping it out. Maybe it is just the change in weather that has kept it from coming on, I really don't have a clue. It's probably just a coincedence.

My post was more of a question and suggestion bundled into one...although it has become a rather intersting read.

ryan if you go to replace it you might not have to remove the intake manifold. Apparently the turbo blocks it from just going in there with asocket, try going in through the #1 and #3 intake manifold runners with a wrench, it might take a while but at least you wont have to remove all that other crap. Or you could try just moving the ps pump and seeing if you can reach it from infront.

Yeah I was looking at that the other day. I got the new purge selanoid the other day in the mail. So far my check engine light hasn't come on, so I may just try and get it smogged before I spend the time replecing it.

I still don't know why the light hasn't come on. It MUST be related to either the tightning of the belt or the IAC valve cleaning. I agree that the IAC is very unlikely. The only other thing is that maybe it was an electrical thing. That check engine light would come on so often I could depend my life on it. Now.....not at all.

It isn't that hard to replace. You definitely don't need to remove the intake manifold. I had one of the small hoses that attaches to the solenoid break when I tried to reconnect it. I actually had to get my wife with her smallish hands to get in there and attach the new piece of hose that I used. In all maybe a 45 minute ordeal, not including the time to find new hose.

-Brian

Did you just use a wrench?

Ok, How did you guys change this thing? You guys with turbos that is. Holy crap what a pain in the arse. I think I can get to it with a wrench with minimal effort, and I may even be able to disconnect the hoses, but how did you pull it out and how did you unplug the electrical connection. It is way under the IAC valve. It didn't sound like you guys needed to pull much off, but I don't see any way around pulling a bunch of crap off my car just to get to the stupid thing.

How did you guys do this?

I just replaced my Purge Valve solenoid. Wasnt too difficult, didnt remove the intake manifold. DID remove the 90 degree turbo inlet pipe though. Removed a plug wire holder bracket thing too. I wish I had smaller hands though... with the turbo inlet pipe off I was able to get a 12mm socket onto the bolt that holds the Valve to the intake mani.