I have two questions, first I'll start with the IAC valve.
I'm getting the infamous idle surging that many of us seem to have. plus the car seems to bog around 3000 rpms when under load. I took out the IAC and cleaned it hoping to resolve some of this. While out I also did this test that phonedawgz outlined in this thread:
I was able to get the plunger to move out but not back in, and it only moved out a little bit. Is that enough to determine anything? I plan on doing the test Hudini talks about in this thread as well:
Looking for any advice, should I just get a new IAC?
I also have a question about the EGR solenoid, the previous owner has what looks to be a vacuum line capped off? should this be connected to something?
That line that's capped off is the fresh air supply for the EGR solenoid. In order for the solenoid to work properly (assuming it works), that line needs to be open to the atmosphere.
That capped hose should be longer and attached to the small metal hose on the front firewall. It pulls fresh filtered air from the air filter canister, providing the hose on the other end hasn't been removed.
There are two styles IAC valves. One has a round, smooth shaft and the other has a slotted shaft. The round, smooth shaft can be retracted by pulling the spring back to separate it from the pintle cone. Screw the pintle cone down, then release the spring and be sure it's ends are in the notches on the backside of the pintle.
The slotted style has to be rocked side to side while exerting pressure against the end of the pintle cone. Don't try to twist it else you will damage it. From the shoulder where the gasket sits, the measurement to the tip of the cone should be 1 1/8 inch or just slightly less, if you want to manually adjust it. Be sure it's not more than 1 1/8 inch when you install it or you will damage it. Be sure the seat in the throttlebody is also clean.
That capped hose should be longer and attached to the small metal hose on the front firewall. It pulls fresh filtered air from the air filter canister, providing the hose on the other end hasn't been removed.
No it doesn't, the hose goes in before the air filter, thus why the whole hose is pointless.
Interesting, not sure why anyone would cap it off then. Sounds like I'll be pulling that screw out then!
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Originally posted by Blacktree:In order for the solenoid to work properly (assuming it works), that line needs to be open to the atmosphere.
I'll search around the forum, but is there a way to test whether the solenoid is working properly?
I'll check what sort of IAC I have and see if I can push it back in. I'm thinking I might just get a new one, haven't been able to find an acdelco one though. Is the one on the fiero store comparable to OEM?
No it doesn't, the hose goes in before the air filter, thus why the whole hose is pointless.
You're right. I stand corrected. It attaches to a nipple on the water separator below the canister and before the air is filtered. There must be some reason that we laymen don't know that Pontiac would have went to the trouble and expense to install that metal line across to pull air from the intake. If it really wasn't needed, I'd think they would just place some kind of foam filter over the hose nipple on the solenoid. Maybe it added positive air pressure to the solenoid or provided cleaner air than what blows up into the engine bay?
That cylindrical piece on the EGR solenoid is an air filter. It filters the air being pulled in through that line. I have no idea why the GM engineers put in a long hose to the air intake. Maybe to make sure it didn't suck in any water?
