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post #1 of 1 Old Today, 03:57 PM Thread Starter
04300exc
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1995 ZJ 
 
Join Date: Jan 2012
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dropping MPG 4.0 ZJ

I am baffled- I have a 1995 Jeep ZJ 4.0, all stock, 230,000 mi. My fuel MPG has dropped from 17 mpg to 13 mpg over about the last 3 tanks. I have not found any fuel leaks. Engine compression is 115-125 psi. ALL plugs are WHITE! (lean). Manifold vacuum is 15 in, and I cannot detect any leaks (I think vac should be 17-21???). Fuel psi is 41 psi at rail. I Purchased a new O2 and will put in today. There is raw fuel smell when I start vehicle in the morning.

Any help would be greatly appreciated.... I am baffled!

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