Pulled my plenum today need some help..

[White 68]

I found that the Secondary port throttle control solenoid does not hold a vacuum ...I assume its the culprit to my vacuum pump running checked all the hoses and the vacuum res.. it all lead to the solenoid ..I also have some other questions with a picture attached but I dont know how to post it ...its big ..Could I email this picture to one of you or anyone who,d like to take a look at it I would apprieciate it ...Thanks Tim.....

So this is where all the knowledge has gone ....

 

[secondchance]

White 68, I am relaying your pic. I noticed its on CF server. Is this cool Rob?
http://temp.corvetteforum.net/c3/sog871//engine_questions.jpg
I have pulled the plenum to fix vacuum but mine was loose fittings. I'm sure someone with more knowledge will chime in.
Good luck!

 

[rhanselman]

Take a look at this link:

http://corvetteactioncenter.com/kb/question.php?qstId=398

Might give you the info you need.

Cheers,

 

[secondchance]

white 68. After you replace the solenoid and get everything straightened out, use small plastic wire ties and where you cannot use the wire tie use epoxy before you button up. Rubber fitting on these hoses go bad very easily.

 

[Rob]

Tim,

In looking at the picture, I'm not exactly sure what that is because of the location. It looks like the secondary port vacuum solenoid, but on the 1990, that solenoid is next to the vacuum reservoir where as your picture shows that whatever that is in mounted on the opposite side of the crankcase ventilation cover next to the coil packs.

I see that you have a 1991. I'm not aware of any changes made to the '91 vacuum system, but maybe someone else can help shed some more light.

Update: Actually, now that I go back and look at the pictures I took, I do see something on top of the crankcase ventilation cover in that same position with a vacuum hose going to it, but I can't say for sure what it is at this point.

 

[White 68]

The item has CAM written inbetween the two port outlets ....its Delco Remey on it with these numbers 201
8160 1

Anyone else know what its called ...Thanks...The large vacuum line that attaches to the underside of the plenum attaches to the right port of this part .....Helllppp...Tim

 

[Demps]

It is the cannister purge valve solenoid (I think). You say it's a 91 right? I think that the other line (out) should track to your cannister purge valve under the driver's headlight (I think 91s are still there, the AIR pump is there on later models and the cannister is reloated to the passenger rear under bumper). It sounds like the operation is normal as it recirculates cannister vapors to the throttle body under different conditions. The out line (actually in) on 95s is at the passenger outside between 6 & 8's intake plenum arm and clips on the aft side--don't know if your's is the same.

ted

 

[Rob]

It is the cannister purge valve solenoid (I think). You say it's a 91 right? I think that the other line (out) should track to your cannister purge valve under the driver's headlight (I think 91s are still there, the AIR pump is there on later models and the cannister is reloated to the passenger rear under bumper). It sounds like the operation is normal as it recirculates cannister vapors to the throttle body under different conditions. The out line (actually in) on 95s is at the passenger outside between 6 & 8's intake plenum arm and clips on the aft side--don't know if your's is the same.

ted

Ah, ok. Thanks Ted!

-Rob