Aurora stalling at idle / coasting

[SSEi95]

My wife's '01 Aurora 4.0 is stalling more and more often when at a stop or decelerating (never while on the gas at all). There is an engine light, but it is unrelated (code for TC slippage). I'm thinking that this may be a fuel delivery issue, either the fuel pump or the pressure regulator. Am I headed in the right direction with my diagnosis? Car runs fine otherwise.

[2000Silverbullet]

Does it have an idle speed valve?

[myfirstbonnie]

I agree with Paul. If it was a fuel pump, you would think it would act worse while accelerating due to the higher demand. The FPR, maybe losing vacume at idle?

[SSEi95]

Not sure if it has some sort of idle speed valve or not. I haven't checked the vacuum yet either. Hopefully this weekend I'll get a chance to get under the hood and look at it.

[unirok]

Did you post this question at http://aurorah.proboards.com/index.cgi ?

[94SilverSSEi]

Well I guess it's time to strip it down and trade it in on cash for clunkers like you were talking about before

[SSEi95]

Not yet, I am a member there too though. I think remodeling might overtake working on the car this weekend. Wife is more willing to deal with the occasional stalling at a light (maybe once a day at most) compared to the drywall mess that is our living room/kitchen/hallway/bedroom/etc...

[SSEi95]

Fuel pressure is at 40psi when ign is on, but not run, 35psi in run and pretty much maintains 35psi as the engine is reved to 3k (not under load). Also took out a front plug (PITA to pull plugs on this one) and it looked to be good. No unusually discoloring or buildup, and the gap is still set exactly at OEM spec. Checked out the vacuum lines and they all seemed to be in good shape. Looked in my FSM, but don't see any reference to idle value or anything like it.

[2000Silverbullet]

So how does the TB control the air bleed when the throttle plates are closed or under cold start conditions?

[SSEi95]

Dunno. I"ll need to look at the FSM some more to see what's next. Maybe it just needs the TB cleaned... who knows.

[harofreak00]

Yes, there is an idle air controller. Apparently you have to remove the EGR to access it though, LOL

Idle Air Control (IAC) Valve Replacement
Removal Procedure
Turn OFF the ignition.


Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical.


Remove the electrical harness (4) from the idle air control (IAC) valve (1).
Remove the exhaust gas recirculation (EGR) valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement .


Remove the IAC valve attaching screws (3) from the IAC valve (2).
Remove the IAC valve (2) from the throttle body.
Remove the O-ring from the IAC valve.

Installation Procedure

Notice
The IAC valve may be damaged if installed with the cone (pintle) extended more than 28 mm (1-1/8 in). Measure the distance that the valve is extended before installing a new valve. The distance from the idle air control valve motor housing to the end of the idle air control valve pintle should be less than 28 mm (1-1/8 in). Manually compress the pintle until the extension is less than 28 mm (1-1/8 in).

Install the new idle air control O-ring on the IAC valve.



Install the IAC valve (2) into the throttle body.

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


Install the IAC valve attaching screws (3). Tighten
Tighten the screws to 3.0 N·m (27 lb in).

Connect the harness connector (4) to the IAC valve (1).
Install the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement .

Important
The PCM will reset the IAC valve whenever the ignition switch is turned ON, then OFF.


Turn ON the ignition with the engine OFF.
Turn OFF the ignition for 5 seconds.
Start the engine and allow the engine to reach a normal operating temperature and check for proper operation.



Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical.

[SSEi95]

Thanx! It's $250 for a new one from rockauto... I may try cleaning it first to see if that helps.

[harofreak00]

Just disconnect it first and see if the idle changes.