91 xlt problems

[umphlett]

i got some questions that i hope you can help me with. i bought a 1991 xlt from a friend of mine a few months back for 500.00. its drivable and looks ok, but its time i got to work on it. my first problem has to do with ilding.when i plug off the vacuum leak on the tee the idle drops, runs rough and has strong exhaust fumes. when i unplug the vacuum the idle goes up to between 1000 to 1500 rpms, idles fine and the exhaust fumes decreases. it runs better with the vacuum unpluged. any ideas? second, does anyone know who sells the speedometer gear? mine broke where it conects to the cable. third, where can i find a good body and suspension lift kit?

thats all for now.
umphlett

 

[MrShorty]

Gut feel for the idle problem would be a bad FPR. Run the engine and check for gas in the vacuum line to the fuel pressure regulator (gas=bad FPR). If that's inconclusive, put a fuel pressure gauge on the fuel rail and see what the fuel pressure is, and if the fuel rail will hold pressure when the pump turns off.

 

[jgilbs]

might try resetting the computer. it may have "learned" to deal with a vacuum leak and plugging the leak throws its settings off. you say it has strong fumes. do they smell like gasoline or exhaust?

you might also try running a bottle or two of seafoam through the vacuum lines to try to burn off some of the builtup carbon deposits in the engine. this stuff really works and will def help, esp on an older truck.