1971 LS5 misfire
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Intermediate
Joined: Feb 2018
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1971 LS5 misfire
Hello,I am working on a 1971 LS5 and I have a lean misfire on cylinder #8. I
have found that the wiper actuator relay is leaking vacuum through the
vent. Vacuum source is from the intake manifold fitting in the #8
runner causing cylinder 8 to have a lean misfire. I realize the vent is to release the vacuum, but should it
cause a constant vacuum leak? The top holds vacuum and the wipers/head
light doors work perfectly. TIA John
have found that the wiper actuator relay is leaking vacuum through the
vent. Vacuum source is from the intake manifold fitting in the #8
runner causing cylinder 8 to have a lean misfire. I realize the vent is to release the vacuum, but should it
cause a constant vacuum leak? The top holds vacuum and the wipers/head
light doors work perfectly. TIA John
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 36
Likes: 1
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
we can't see from here where the vacuum leak is. start at the intake and move down stream checking every hose and conection you can get to. goes in to interior and back out to engine compartment. try capping everything where it comes out for headlights and wiper dor. if you still have the miss, go inside and cycle all the vacuum switches and see if miss goes away.
