toms93lx

SIMPLE QUESTION GUYS. I HAVE A 1993 5.0 LX AND NEED TO KNOW HOW TO DO A VACUM CHECK ON IT. I AM SURE ITS GOOD BUT NEED TO CHECK IT.

LOOKING LIKE I HAVE TO TAKE IT TO FORD TO FIGURE THE OTHER STUFF OUT. NO ONE KNOWS AND I DONT WANT TO THROW PARTS AT IT. BUT THATS THE WAY IT GOES I GUESS.

I CANT FIX THE IDLE HANG UPS AND HIGH IDLES. AND TOOK IT TO A SHOP AND GOT NO CODES. BUT ONE QUESTION.

MY TPS IS SET AT .76 AND RUNS UP TO 3.7 WHEN WIDE OPEN
IF THAT MEANS ANY THING.

LAST RESORT IS A VACUM CHECK. LUCKILY NOT MANY VACUM HOSES SO I MIGHT JUST CHANGE THEM ALL OUT.

HOW DO I TEST IT AND WHERE DO I TEST IT

ryan_89_mustang

Have you tried cleaning or replacing the IAC valve because that could cause a hanging idle/ high idle if it is sticking in place.

toms93lx

yep cleaned it and cleaned it and cleeaned it

TrimDrip

buy a gauge

toms93lx

i know buy a gauge but were do i check it

Jon82387

plug the gauge into the vacuum tree on your firewall? should be an empty spot if not just pull off your brake booster hose.

mattdel

cleaning the valve wont always work. You'd be able to hear a vacuum leak if it was causing a high idle. Hate to be a part slapper but an IAC valve is the most likely culprit here and I don't happen to have any testing instructions in front of me for it.