How fast should light come up?
Thread Starter
Intermediate
Joined: Mar 2008
Posts: 26
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From: Greenville SC
How fast should light come up?
Many of you guys have told me to look for vacuum leaks because of my poor idle problems. I'm still looking, but another question.
One thing going on is when I pull the light valve to bring them up, it takes about 8 secs for the first light to come up and a few seconds later the second will come up albeit slowly.
If all is tight and well, how long should it take for the lights to pop up and should they be coming up one at a time or both together? Same question for going back down.
I have 20 inches of vacuum at idle with this stock 74 L48. When I disconnect the light system from the manifold and plug it, all of a sudden the car seems to idle better.
Ochsy
One thing going on is when I pull the light valve to bring them up, it takes about 8 secs for the first light to come up and a few seconds later the second will come up albeit slowly.
If all is tight and well, how long should it take for the lights to pop up and should they be coming up one at a time or both together? Same question for going back down.
I have 20 inches of vacuum at idle with this stock 74 L48. When I disconnect the light system from the manifold and plug it, all of a sudden the car seems to idle better.
Ochsy
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Vacuum Head Light Problems Solved!
Hi ochsy, here's a good link http://www.corvette-101.com/vacuum.htm You can also try to cut about 3/4 of an inch off each line and reconnect them, sometimes the ends get stretched and leak. Also the a shot of penetrating oil into each port on the relays can help. PG.
Drifting
Joined: Jan 2004
Posts: 1,991
Likes: 3
From: Piscataway NJ
You have to fix the vac leaks first. Then get under the car and check the condition of the springs on the headlamp assembly four springs per lamp. Check all moving linkages for lubrication. There are also two pivot bearings for the H/L door each side. My left side goes up alittle faster than the left in my 77. I have the electric driven lamps in my 73 they come up instantly. Whats the diffrence...none they both achieve the same purpose.
Abby Normal
Joined: Dec 2001
Posts: 53,461
Likes: 92
From: Press "2" for English
the real indication is what you said about the car idling better. you have a very distinct vacuum leak in the headlight system. it will either be the relays mounted just forward of the hood opening on the underside of the nose 'glass. the other likelihood is the seal on the front of the diapragm. the sad reality is it's probably both.
get it fixed. vacuum leaks are bad for engines.
get it fixed. vacuum leaks are bad for engines.
