Vacuum question.
Thread Starter
Intermediate
Joined: May 2007
Posts: 44
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From: Racine Wi
Vacuum question.
Does anyone have a good layout of all the vacuum lines for an 87? I have the Chiltons for the C4 but it skips the 85-89 vacuum diagrams.
I think i have a leak somewhere but I may also have one running the wrong way. The guy before me removed the vacuum canister and charcoal canister when he installed the Carb. How important are these and can I block this off for now or are they monitored and confusing the computer?
I also believe I have a leak because I can't get the timing to sit at the mark. Either 8btc or 8atc. As soon as I get near the 5 mark it either drops or rasies a bunch. This sound like vacuum or should I be looking elsewhere?
I think i have a leak somewhere but I may also have one running the wrong way. The guy before me removed the vacuum canister and charcoal canister when he installed the Carb. How important are these and can I block this off for now or are they monitored and confusing the computer?
I also believe I have a leak because I can't get the timing to sit at the mark. Either 8btc or 8atc. As soon as I get near the 5 mark it either drops or rasies a bunch. This sound like vacuum or should I be looking elsewhere?
Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
Have you put the tpi back on ? If the computer is operating the ignition, did you unplug the esc wire when you set the timing ? You may get more help, if you give us some details. 
Thread Starter
Intermediate
Joined: May 2007
Posts: 44
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From: Racine Wi
TPI back on
TPI is now back on. The sticker there but only shows the engine circuits. All that is good except the vacuum canister and charcoal canister are gone. I did not disconnect the ESC. That's the 4 pin on the back side correct?
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
Try your timing again. Disconnect battery and recconnect EST after setting timing to clear code caused by unplugging EST.
Buy a used vacuum canister and charcoal canister from a corvette salvage yard, reconnect hoses, and you're done.
Last edited by 86PACER; Aug 9, 2007 at 02:09 AM.
Thread Starter
Intermediate
Joined: May 2007
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From: Racine Wi
Didn't see that one.
You need to, in order to keep the idle steady when setting timing. Read the emissions label on driver's side of radiator shroud, near upper radiator hose. Disconnect this one:
Try your timing again. Disconnect battery and recconnect EST after setting timing to clear code caused by unplugging EST.
Buy a used vacuum canister and charcoal canister from a corvette salvage yard, and you're done.
Try your timing again. Disconnect battery and recconnect EST after setting timing to clear code caused by unplugging EST.
Buy a used vacuum canister and charcoal canister from a corvette salvage yard, and you're done.
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Thread Starter
Intermediate
Joined: May 2007
Posts: 44
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From: Racine Wi
Thanks again.
It's amazing what a couple of hours on the web can do if you ask the right people. Cars working great. I just need to pick up the few last missing pieces and she'll be done.
