Tune up gone wrong!

So I decided to bite the bullet and give the winter beater a tune-up... now I wish I hadn't because it won't stay running. I replaced the plugs, PCV, Air Filter, and Fuel Filter.

The old fuel filter was quite rusty and stuck in the line pretty good but I eventually got it off. Now when I fire it up it won't stay running unless I give it half-throttle or more. It doesn't seem to be misfiring when it is running which led me to believe its not getting enough fuel.

I checked to make sure I didn't put the filter in backwards, and also removed all the plugs to see if I broke any, and checked that the plug wires were seated. I installed them one by one so the wires aren't mixed up. I also put the old PCV back in to see if anything changed but it didn't. And I checked for intake leaks but found none.

Any ideas? Is it possible that the fuel line got a clog or kink in it? And if so, can I blow some air through the bleeder to try to back-flush it out of the line?

This is for a 1993 Mercury Grand Marquis BTW.

I think these cars have a return-style fuel system so if it were clogged it wouldn't rev up at all, am I correct in saying this?

hotrodredneck said:

you have a vac leak somewhere. Probably a little hose that you forgot to hook up or maybe you left the IAT (intake Air Temp) sensor disconnected. Double checl all your vac lines and elect connectors

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Found it. It was the one going to the back of the lower intake so I couldn't see that it was off. Thanks.