Rough Idle and stall on cold start
 

Hello,

I have an XG350 2004 with 60k miles on it. The first start of the day is rough. The car idles very very rough and and sometimes stalls. The engine will sometimes rev up by its self just before stall.

Im in the process of changing all plugs and EGR valve. Any one else had this or can point me in the right direction? Once its warm it idles well.

The ECU throws codes of random misfile or sometimes a couple specific cylinders.

Thanks for the help!

Bruce

Could it be the IAC - Idle Air Control Valve? I almost feels like the engine is starving for oxygen.

IAC or EGR

Thanks EGR is first. We will see!

Here is what I have changed (shooting from the hip somewhat):

*EGR Valve
*Idle Air Control Valve
*Injectors (All 6)
*Plugs (NGK Iridium)
*Cleaned upper inlet manifold and throttle body completely and resealed.
*New throttle body gasket and Intake manifold gasket.

It ran smoother and I thought I had it.....but NOPE. Today after sitting 9Hrs at work I get in and ....grumble grumble grumble, problem is still there!

So I think it is a fuel delivery issue.

ANY THOUGHTS?

Next:
*Fuel pump
*Fuel pressure regulator
...
*burn the car to the ground. (JOKING)

ALL HELP APPCIATED!

Well, it sounds to me like you got all the bases covered
And it should be working well

Is there water in the gas tank?
Maybe some fuel cleaner??

tried fuel cleaner.

Then it seems it has got to be the pump or regulator

My clue that is pressure regulator:

-Black plugs
-Bad MPG

Crank shaft position sensor?

I dont expect that to be the issue. If that was the problem I would expect a code relating to it.

Update
 

I noticed a pattern. It starts perfectly fine on cold mornings. The fuel trims are way negative, indicating a rich condition which the computer is compensating for. -15% and -19% on each bank.


Will be changing fuel pressure regulator this weekend.

Solved!!!!
 

:D

Fuel pressure regulator was the problem. Starts smooth and idles fine now.

Better fuel economy and smoother engine.

Was trouble repaired?
 

I have the same trouble with my 2004 XG350....65k miles.....any luck with your troubles yet?

Ooops, sorry, missed your final threads....cool will try the fuel regulator. Thanks !

If the fuel press regulator doesn't correct the problem, consider the crank sensor.
Here is why;
A malfunctioning crank sensor "Does not throw a code" !
If everything else checks out , smart move to change it.

[QUOTE=brucelee;53407]Hello,

I have an XG350 2004 with 60k miles on it. The first start of the day is rough. The car idles very very rough and and sometimes stalls. The engine will sometimes rev up by its self just before stall.

Im in the process of changing all plugs and EGR valve. Any one else had this or can point me in the right direction? Once its warm it idles well.
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As an ASE Certified Master Automotive Technician, I honestly try to advise everyone to not waste their time and money replacing plugs, primary/secondary ignition etc until the actual problem has been properly diagnosed. I honestly wish I could start charging my customers extra money if they worked on the vehicle first. 99 times out of 100 they end up ruining a cylinder head from improper plug installment or they don’t know that a plug is supposed to be torqued to the proper specs. Years ago I also had problems with people not knowing that a plug needs to be gapped or what that even meant LOL Even though these days most plugs are pre-gapped, most people end up causing more problems on top of what was wrong already and I’m forced to fix whatever it is that they did wrong before I’m able to begin making a diagnosis on the original problem. So under most circumstances I advise people to leave the vehicle problems to a good, trustworthy technician (avoid chains and franchises at all costs!!!!!). Unless you have some form of automotive repair training and own a professional set of tools, I really can’t stress enough how important it is to give the car to a service professional as is! Not only will it save them a headache, but it will save you time and money 💰💰💰 Hope this helps!