The last two times I’ve driven my 88, I noticed a fairly strong fuel smell that comes 45 minutes to an hour after I turn the car off. I have traced the smell to the back half of the plenum/intake around the FPR & CSV area. I can see no traces of fuel moisture and I do not smell anything as I move forward on the intake. So, I feel pretty confident that I have isolated the area. Thinking that I may have a leaking injector, I hooked up a pressure gauge to the fuel rail and got the following leakdown numbers. I’m not sure if these numbers are acceptable.

45psi with Key On (not starting)
36psi @ Idle For 10 minutes
41psi with Key Off
39.5psi @ 5 min, 38.0psi @ 10min, 36.5psi @ 15 min
35.0psi @ 20 min, 33.0psi @ 25 min, 32.0psi @ 30 min
30.5psi @ 35 min, 30.0psi @ 40 min, 29.0psi @ 45 min
28.0psi @ 50 min, 27.0psi @ 55 min, 26.5psi @ 60 min
26.0psi @ 65 min, 25.0psi @ 70 min, 24.5psi @ 75 min
24.0psi @ 80 min, 23.5psi @ 85 min, 23.0psi @ 90 min
22.5psi @ 100 min, 22.0psi @ 110min, 21.0psi @ 120min

Also, when I disconnect the vac line going to the plenum from the FRP, it's dry with no fuel smell. The car starts great whether it’s hot or cold and runs well. The only other thing I’ve noticed, sometimes while driving it takes a few seconds for the idle to settle down when coming to a stop. Not sure what to look at next...thanks.

 

......look and feel around the csv at the rear of the engine......mine leaked periodically but not all the time.....replaced the "o" ring(s) on the csv where it connects onto the fuel rail and that solved the problem.....

 

Loosen your fuel cap and drive around like that for a few days. If the problem goes away, it's probably your vapor canister / tank venting system not working properly.

 

Good call!

 

Thanks Mail Man...that's exactly what it turned out to be. Don't know why I didn't find the moisture on that fitting earlier. Anyway, a quick trip to Advance Auto and $6 for the fuel rail o-ring kit, it's fixed. Thanks Again.