another high idle question

I have a 93 f150, 5.0 that doesn't want to idle right.It will idle about 1200 rpm, then settle to about 1,000after 30 seconds. When driving, it will stay at 1500rpm between shifts. If you coast to a stop in nuetral the idle will hunt between 1000-1500. I bought a code scanner to help diagnose a high idle when warm problem.I have replaced the map sensor, Idle air control valve,tested the tps, air charge sensor, O2 sensor, and coolant temp sensor. Cleaned the egr valve, pcv, and the throttle body. I took it for a short drive after clearing the codes, tested it again and it gives me a code 12-13-44. The truck still gets 14 mpg so something is still working right. Also, I sprayed starting fluid around the mainfold and vacuum lines to test for leaks- no joy. Any other ideas? I'm leaning toward testing the injectors for leakage or replacing the computer.

I have a 93 f150, 5.0 that doesn't want to idle right.It will idle about 1200 rpm, then settle to about 1,000after 30 seconds. When driving, it will stay at 1500rpm between shifts. If you coast to a stop in nuetral the idle will hunt between 1000-1500. I bought a code scanner to help diagnose a high idle when warm problem.I have replaced the map sensor, Idle air control valve,tested the tps, air charge sensor, O2 sensor, and coolant temp sensor. Cleaned the egr valve, pcv, and the throttle body. I took it for a short drive after clearing the codes, tested it again and it gives me a code 12-13-44. The truck still gets 14 mpg so something is still working right. Also, I sprayed starting fluid around the mainfold and vacuum lines to test for leaks- no joy. Any other ideas? I'm leaning toward testing the injectors for leakage or replacing the computer.

Both 12 and 13 are that the RPM couldn't be controlled during the test but the 44 is the important one:
44 Secondary Air Injection system Inoperative (right side).


Have you checked into this fault yet?

The only place for air injection is into the cat. I don't have any thing in the converters (they're empty). I don't see any sensors on the pump or control valve so I'm assuming a fault code that comes from a mixture problem.The cats have been empty for a while with no problem. The engine controls idle good when cold, just not when warm. I also cleaned the connectors on the ECM and Abs modules. At 205,000 miles I think it's time for a general going over.

ok, the code 44 was "problem with thermactor system". Ater replacing the hose from the air pump to the diverter valve, The idle started to readjust. (It is learning). Also I had replaced the throttle body gasket with one I had made and found that I didn't cut the relief for the Iac. Much better now.

my idle control switch went bad and it idled like hell.

I also on a 98 150 v6 had sprayed to find vac leaks but it was so bad it never changed!!! i changed about everything the putor said was wrong but still kept going back to the same codes over and over..I finnaly tore off every vac hose connection off and found 2 bad elbows..that I had sprayed befor..one I had to use a very long needle nose in to even get to it..all it ever was was vac leaks..

Mine also did this only after it got warm...the one elbow would start sucking air after a 5-10 mins after start up,,I only found this one when I had my hood open and heard it pop and start sucking air..Good luck

Mine also did this only after it got warm...the one elbow would start sucking air after a 5-10 mins after start up,,I only found this one when I had my hood open and heard it pop and start sucking air..Good luck
See my post -- search for idle or erratic mileage-- on the continuing saga of life with Ford. Thanks for the heads up.

Mine also did this only after it got warm...the one elbow would start sucking air after a 5-10 mins after start up,,I only found this one when I had my hood open and heard it pop and start sucking air..Good luck


See my post -- search for idle or erratic mileage-- on the continuing saga of life with Ford. Thanks for the heads up.