enfausn

Hi all. Just joined the site today and just got my project car last week. I've got an 89 LX 5.0L Notch. It hunts a little at idle. At first I figured it just needed a tune up. I tuned it up with a Summit cap and rotor, Ford Racing wires, NGK plugs, MSD Street Fire Coil, and an Accel Ignition Module. I set the timing to the factory 10 degrees. I also pulled out the factory intake silencer in the fender and put a new air filter in it till I can get a new cold air setup. Thing still hunts up and down at idle a little. I can hear the fuel pump speeding up and slowing down with the engine speed as it idles. I was wondering if anyone else had chased this problem before or if this was normal. This is the first foxbody i've ever had so I wasn't sure if this was a common thing or not. If anyone has any suggestions that'd be great......Thanks in advance.

mjr46

as idle surges up and down so will the voltage output of the alternator as it is rpm dependant, the fuel pump of course will do what it's doing since it is driven by current.....it is not your problem, run a koer test and check for codes first.

87GT Drop Top

Try cleaning the throttle body. I had the same problem and cleaning the TB fixed it.

enfausn

Thanks for the info on the throttle body......I'll give that a try tomorrow. I ran the test and this is what I got. This is the first time i've ever done one of these so bear with me...LOL. I think I got a 22 code on the KOEO test and a 23 on the stored codes part. It didn't flash at first then went flash, quick pause, flash, pause, flash, quick pause, flash, longer pause, flash, long pause, then repeated the 22. (Pretty sure that's 22 right?) After starting it it flashed 23 once. I hit WOT to start the balance test and got four numbers 7, 6, 7, 7. I looked up the codes and They are for the MAP sensor and TPS voltage. So, I'm going to adjust the TPS like I've seen in other threads, check the MAP and clean the throttle body tomorrow. Gotta look up balance test codes but think I'm on the right track. Thanks for the info guys!

enfausn

Ok looked up all the balance codes.....When it refers to cylinders failing is it refering to the injector failing or the plug??? Sorry for being such a newbie, I'm familiar with obdII but just starting out on this system. Feeling a little retarded.....LOL. thanks for the help with the learning curve!

mjr46

refers to those cylinders were not contributing during test, could be spark related or fuel, retry the test and see if same codes are output twice in a row

enfausn

Ok, here's the update.....LOL. I fixed the MAP code (bad connection) and set the voltage on the throttle position sensor. It's dead a .90 volts at idle. It's idling better but still throws a 12 code for idle speed control out of specified range. I don't have a clue what to do about this since you can't adjust the idle speed on these cars. Any suggestions would be great. thanks!