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#1 |
Registered User
Join Date: Jan 2009
Location: Pittsburgh PA
Posts: 16
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On my 4th MAP sensor
the MAP sensor in my 87 Chevy 350 TBI keeps going bad. I have checked for vacuum leaks and everything is fine. Checked the voltage at the sensor and with just the key on it reads about 4.69. Using a vacuum gage the voltage drops about 1 volt for every 5 psi. I installed a clear hose from the TBI to the MAP sensor and I have noticed fuel in the line. Not vapors but actual fuel that is sloshing around. I'm thinking that is not normal and could be causing my sensor to keep going bad. Anyone have any thoughts on this? Thanks.
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#2 |
Senior Member
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
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Re: On my 4th MAP sensor
You likely found your problem. there should be no fuel in the vacuum lines period. Im sure the fuel is killing the map sensors. Its not designed to handle the fuel. I would suspect the throttle body is leaking fuel internally allowing it to get into the vacuum circuit.
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Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. |
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#3 |
Formerly- 1972SuperCheyenne
![]() Join Date: Oct 2008
Location: Wake Forest NC
Posts: 5,782
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Re: On my 4th MAP sensor
You just hit the nail right on the head. Time to rebuild that throttle body.
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--Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with. |
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#4 |
Registered User
Join Date: Jan 2009
Location: Pittsburgh PA
Posts: 16
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Re: On my 4th MAP sensor
Thanks, thats kind of what i was thinking. But I've already rebuilt it once. I was going to do it again anyway so i was hoping that might fix the problem.
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