'95 4.0 AWD. I've been having problems on a cold start that there will be a hesitation/stumble on first take off. I've cleaned the IAC but this tsb seems to say I need to replace it. I'm gonna do that tomorrow!!

Found a TSB:

Engine - Hard Starting/Long Crank/Stalling
Article No.
97-9-5
04/28/97

LONG CRANK - STICKING IDLE AIR CONTROL (IAC) VALVE - VEHICLES BUILT FROM 11/1/94 THROUGH 3/30/96

STALL - AFTER STARTING WHEN ENGINE ALLOWED TO SOAK FROM 1-4 HOURS - STICKING IDLE AIR CONTROL (IAC) VALVE - VEHICLES BUILT FROM 1/11/94 THROUGH 3/30/96

FORD:
1995-96 CONTOUR, CROWN VICTORIA, ESCORT, TAURUS, THUNDERBIRD
1996 MUSTANG

LINCOLN-MERCURY:
1995-96 CONTINENTAL, COUGAR, GRAND MARQUIS, MARK VIII, MYSTIQUE, SABLE, TOWN CAR, TRACER

LIGHT TRUCK:
1995-96 AEROSTAR, BRONCO, ECONOLINE, F-150-350 SERIES, RANGER, WINDSTAR

1996 EXPLORER

This TSB article is being republished in its entirety to include the 1995 4.6L Thunderbird/Cougar.

ISSUE:
After a 1-4 hour engine soak time, long crank times and/or long crank to start followed by a stall may occur on some vehicles. No further stalling or rough idle will occur after the engine is running. The long crank and/or stall may be due to the Idle Air Control (IAC) Valve sticking.

ACTION:
Replace the AC Valve with a revised AC Valve if no Diagnostic Trouble Codes (DTCs) are present. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Perform normal diagnostics and correct any DTCs as required by referring to the appropriate year Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual.

2. If no codes are present, replace the IAC Valve by referring to the appropriate model/year Service Manual, Section 03-14. Refer to the following Idle Air Control Valve Application Chart for proper IAC usage.

 

Update: after replacing my '95 IAC with a '93 IAC the problem has definitely reduced but it's not totally gone away yet. I did disconnect the battery for 20 mins. I'd like to try a brand new one but they're about $90 here in Canada vs. the used one at $35. It definitely has increased the idle speed in the cold weather - the other one was certainly malfunctioning.

 

1996 Ranger 3.0. Hard to no start in the morning. After warm or runs a while, starts and run fine. Was told it could be the cam position sensor? Any suggestions?

 

rbj0722
welcome to FTE and the Aero forum

your engine control computer is OBDII EEC-V
lots of guesses for cold start problems

have the codes read for free at auto parts store, call ahead
post codes here.
or buy/borrow code reader/scanner

same engine as used in later Aeros

 

Advance read the codes for me and found 3. They were "Engine Coolant Temp--Circuit Low Input", "Camshaft Position Sensor A - Bank 1--Circuit Malfunction" and "EVAP Emission Control System--Cntrl Valve Malf".

I bought the Camshaft Position Sensor to replace it. Found the magnant broken of the old one and the cam bent. The new one would not fit. Purchased the cam syncronizer. Have not itstalled it yet but expect that to solve the Cam Position Sensor trouble. Don't know about the others yet.

 

There is one big engine wiring connector. Try to disconnect it, inspect for corrozion, clean if neccesary.

 

you may have a bent shaft on the cam sensor position unit or a broken worn gear causing shaft wobble.

the ECT is the likely cause of the hard cold starts and rough cold idle. may be sensor or its wiring/connectors
common Ford failure
2 wire sensor on side of thermostat housing outflow tube to radiator.
Ford Fuel Injection Engine Coolant Temperature Sensor (ECT)

includes testing instructions for sensor

 

The evap Purge control valve or solenoid gets sticky due to carbon dust build up. Take off the purge solenoid & blow out the lines & spray carb cleaner into the solenoid ports, while shaking out the gunk. You can also energise the solenoid with a 12 v source & you will hear the valve open & close while touching the terminals. If nothing happens reverse the wires. Blow through the ports with an air gun while this is going on (need an assistant). At the engine wire plug to the solenoid: this connection to the solenoid should be come live 12v at about 1500 RPM's intermittently which opens the purge valve, if not you have an electrical or ECU problem. Check wires to ECU. It is also possible the purge flow sensor is faulty if yours has one. You can try the same air blow carb cleaner trick on it, but might need a new one.

ECT is likely pooched, sounds like cold start enrichment is not happening.

Also you need a junkyard Camshaft Synchroniser with CMP sensor on it ( about $30-40 where I am). The unit needs to be timed; note where the old one is before you remove it & put the replacment in the SAME position , don't allow the engine to rotate .

ATB Aeroman.