yo elpapisf,
in all Respect to NaturalRampage, may I suggest that you not adjust that ***** yet,
Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19
http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded
The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test (try if you can get it to run long enough after doing the rest of the tests here).
Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.
Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.
Do Key On Engine Off (KOEO) portion
Idle Air Control (IAC); also called, Idle Air Bypass (IAB), Idle Speed Control (ISC), Throttle Bypass Air, Idle Bypass, Inlet Air Controller, Inlet Air Bypass, Intake Air Bypass, Intake Air Control
Idle Air Control (IAC) Sludge; Poor Idle TSB 91-25-07 for 85-92 Bronco & F Serie Source: by Nelbur at Ford Bronco Zone Forums"For most of my trucks life it has been dying when it was started hot. It would rev up and then drop the idle so low it would die unless I would catch the idle with the accelerator. It would never die when cold as the IAC would keep the idle speed up, and it never died at stop lights. Now it's worst situation seems to be when it has been shut down for a half hour or so, and restarted. I wonder if the heat soak is fooling the ETC into thinking the engine is warmer than it really is.
I have spent some time this week trying to set up an air bypass around the IAC valve by cutting away some of the gasket between the IAC in and out air holes, rather than pay big bucks for Fords spacer kit. I cut away the center of the original IAC gasket from the outside of each hole to the outside of the other hole, giving about 1/2" gap for the air to pass through. I noticed an immediate improvement in the engines starting behavior, but it would still die occasionally.
decided that more improvement could be had if I had a thicker gasket, because the original IAC gasket was very thin (0.018"). I had some 0.030" gasket material so I made my own with the same 1/2" cut out. This gave enough bypass to noticeably raise the idle speed and almost eliminate the dying. After maybe 50 starts in the last few days, it only died twice. After so many years of catching it with the accelerator it is darned hard to leave my foot off it. It is clear to me that by trial and error one can tune the air bypass without the need for the expensive Ford kit. I may combine the two gaskets for more bypass, but the idle is about as fast as I would want now, especially for driving in snow."
Idle Speed Adjustment in Idle Air Control (IAC) Sludge; Poor Idle TSB 91-25-07 for 85-92 Bronco & F Series & many others; "...Detailed application charts for throttle body and idle air by-pass solenoid service procedures by engine VIN #/engine displacement/vehicle application and model year are shown. Refer to these charts to see if the service kit is to be installed and which service cleaning procedure, if any, is to be used..."
PROCEDURE #2
IDLE AIR BY-PASS VALVE CLEANING ONLY
CAUTION: THIS CLEANING PROCEDURE MAY BE USED WITH SLUDGE TOLERANT THROTTLE BODIES WHICH ARE IDENTIFIED WITH A YELLOW/BLACK "ATTENTION" LABEL AND THOSE USING SERVICE KIT (F2PZ-9F939-A). NO ATTEMPT SHOULD BE MADE TO CLEAN THROTTLE BODY BORE/PLATE AREA BY DIRECT SPRAYING OR SCRUBBING. DO NOT RUN VEHICLES WITH AIR FLOW METERS DURING CLEANING PROCEDURE.
Plug the actuator into the connector in the Rotunda Air By-Pass Valve Adapter 113-00009, or equivalent.
Remove the air duct to the throttle body inlet.
Disconnect the idle air by-pass valve signal lead.
Attach the actuator harness plug to the idle air by-pass valve.
Start the actuator and then start the engine.
NOTE: DO NOT START ENGINES THAT HAVE AIR FLOW METERS.
Spray the Carburetor Tune-up Cleaner for about five (5) seconds into the idle air by-pass valve inlet passage while the actuator is operating.
CAUTION: AVOID DIRECT SPRAYING ON THROTTLE PLATE/BORE AREA
Stop the engine and actuator. Let everything soak for fifteen (15) minutes.
Start the actuator and the start the engine.
CAUTION: DO NOT START ENGINES THAT HAVE AIR FLOW METERS.
Spray Carburetor Tune-up Cleaner into the throttle bore for up to one (1) minute.
CAUTION: DO NOT SPRAY FOR LONGER THAN SIX (6) CONTINUOUS SECONDS ON ENGINES THAT HAVE AIR FLOW METERS AND ARE NOT RUNNING.
Stop actuator and stop engine if running.
Reinstall the air duct.
Start and run the engine for about one (1) minute to dry out the solvent residue.
Operate the actuator to make sure the solvent is purged from the idle by-pass valve.
Disconnect the actuator from the idle air by-pass valve.
Reattach the control signal lead to the air by-pass valve.
Check engine for normal operation.
NOTE: IT SHOULD NOT BE NECESSARY TO RESET THE IDLE SPEED SINCE ONLY THE IDLE AIR BY-PASS VALVE WAS SERVICED IN THIS PROCEDURE
Spacer Plate Depiction; hard cold starts, stalling hesitation, rough idle, rolling idle, etc; clean the throttle bore, plate & air bypass valve; service kit (Part No. F2PZ-9F939-A) to prevent sludge accumulation in the throttle bores of many of its 1983-92 EFI vehicles (except those with sludge-resistant coatings). The kit contains two gaskets, a spacer plate that you put between the air bypass valve and its mounting boss and installation instructions. Ford says installing the kit will eliminate the need for periodic cleanup of the throttle bore and plate, and as such, no longer covers the procedure under its 5-year/50,000-mile emissions warranty. If you prefer to go a different route, be aware that Tomco recently introduceda similar kit to the aftermarket under Part No. 8491. If you’d like more information, call Tomco at 314- 567-4520 for specific year and model coverage..."
Source: by Seattle FSB (SeattleFSB) at SuperMotors.net
Vacuum Leak Symptoms & Overview; Surging,
Rough idle, rich fuel condition, which may cause spark plug fouling, Detonation due to too much spark advance and a lean fuel ratio, loss of power and/or fuel economy due to ******** timing and an excessively rich fuel ratio; a vacuum leak will reduce intake vacuum and cause the MAP sensor to indicate a higher than normal load on the engine. The computer will try to compensate by richening the fuel mixture and retarding timing, which hurts fuel economy, performance and emissions.
See my Vacuum Leak Test @
http://broncozone.com/topic/22770-low-idle/
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