88 LX 5.0 IDELS AT 2000 RPM

See "Help me create the Surging Idle Checklist" at http://forums.stangnet.com/showthread.php?t=698148
for help with your idle problems. The first two posts contain all the updates to the fixes. I continue to update it as more people post fixes or ask questions.

jesus man, you're car is a basket case.

first of all, you should have bought a car that wasn't mickey moused from a prior owner, unless you're REAL good at 5.0 cars.

secondly you can't just remove the o2's if you have fuel injection. It just doesn't work. O2's play an integral part with the computer. Put the o2 sensors back in, that's a MUST

secondly, unless he swapped to a speed density compliant cam, which is highly unlikely,...that cam isn't compliant with your speed density. converting to mass air at this time is a MUST for you. It's easy with your car, just get an 88 (cali) or 89 mass air harness, computer, meter and plug and play. This will help tremendously with how your car runs.

after you do those two things, then you can start to work from there.
Next thing to do is check for vacuum leaks. If the previous owner was dumb enough to pull the o2's out, no doubt he ripped out all the smog and vacuum too. check your vacuum for leaks, and to make sure everything is hooked up right. the essentials are a dedicated line from the upper intake vacuum to the fuel regulator, and a dedicated vacuum line from the upper intake to the MAP sensore (when you upgrade to speed density, your map no longer needs a vacuum signal) also, be sure you have the single thin line that goes from the intake to the egr/tab/tad solonoids on the firewall. You've also got a line off the front going to the charcoal canister, and finally a line going from the intake to the pcv in the lower intake, and from the intake to the vacuum tree on the firewall. Off that tree, you get the a/c vacuum lines. check ALL of that, and plug off what you aren't using.

learn the basics..set your timing, the check your tps... set that if it's off. after all of that, a high idle can be caused by the idle air control motor from the front of the intake. check that. You could also try setting the idle speed, but ONLY after everything else is done. I won't describe that procedure because you aren't ready for that.

sounds like you're gonna have a HUGE crash course in efi 5.0 powerplants. BTW, keep the efi, you'll be happier with it.

A hanging idle is likely the result of a bad air idle control motor; try removing and cleaning that first and see if it helps. Try getting 02's hooked back up. As for the cam, hopefully they didn't go too wild. The speed density vehicles can be kind of picky if it's anything other than a ford E-cam. Try to get your issues sorted out before converting to mass-air. The speed density motors actually run harder than mass-air equipped ones until your engine mods go beyond what the speed density system can handle. Stay with the fuel injection; it's a lot nicer.

NKau said:

A hanging idle is likely the result of a bad air idle control motor; try removing and cleaning that first and see if it helps. Try getting 02's hooked back up. As for the cam, hopefully they didn't go too wild. The speed density vehicles can be kind of picky if it's anything other than a ford E-cam. Try to get your issues sorted out before converting to mass-air. The speed density motors actually run harder than mass-air equipped ones until your engine mods go beyond what the speed density system can handle. Stay with the fuel injection; it's a lot nicer.

Click to expand...

I agree, I had the high idle twice and both times it was the IAC valve. Once I got away with cleaning it. The 2nd time I bought a new one.