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5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
Well, an update. We got the car running after replacing the fuel filter, adding some seafoam, and cleaning out the MAF, however it backfires ALOT now (after reving high and letting off the gas, it sounds like a hot rod), idles extremely low (like about 500 rpms (not 500k), and stalls out. It also seems to drive rough. I can't really think of what else it could be. Any ideas?
it sounds like its still having trouble getting gas...backfiring means its running lean. hmmm...you might have to pull and clean your fuel injectors. or you could have something clogging a fuel line. you might want to get the advice of somebody who's a better mechanic than me though
The car may need to just run for a while, clean out all the old fuel, computer has to relearn everything also. Let her sit and idle for a good while and see if some of her symptoms clear up.
Did you ever totally drain the tank, if not, I would, then put some fresh gas in it. Also, have you checked to make sure none of your vacuum lines are leaking?
drain the tank and check for vac lines leaking...can cause idle surges. also the computer will have to relearn everything so just drive it alot to help fix that.
Found the problem! Removed the MAF sensor and the car ran perfectly fine. Going to get the MAF replaced this weekend, so I can get my car back on the road, w00)!
Nice job fellas. I was about to go on a tirade about gas turning to varnish, and other such nonsense. Glad you figured out the problem, man. Enjoy that new (to you) Mustang.