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Fuel Pressure too High.

ajporter03

NAXJA Forum User
Location
North Logan, UT
I have been getting pretty poor gas mileage lately. And I think that I might have found the problem. My fuel pressure seems to be too high. At idle with the vacuum line connected I get 39 psi. With the vacuum line disconnected I am up near 45 to 47 psi. The haynes book says to check for a blocked return line. I couldn't find any problems. So I disconnected the return line right at the fuel rail and hooked a line straight into a gas can. No change. I am pretty sure that I need a new regulator, but before I bought one, I just wanted some opinions.

It is a 93 XJ 4.0 aw4. I am pretty sure that the fuel pressure should be 31 at idle vacuum line connected and 39 with it disconnected.
 
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