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CEL: Engine stumbling stuttering and wanting to shut-off

 
Old 06-25-2019, 03:52 PM
  #31  
808Bill
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Does anyone read between the lines anymore?
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Old 06-25-2019, 06:46 PM
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Originally Posted by DBJoe996 View Post
Unplug the MAF sensor on the airbox and see if the idle changes. Also might consider disconnecting the battery neg terminal for 30 minutes and that will reset the DME/ECU to default base values. When was the last time the TB was cleaned,...and the Idle Control Valve (if you have cable throttle)? Check the clamps on the main air box hose...make sure they are tight.
Thank you for the suggestions. I'll give this a shot.

The TB is pretty clean. However, I can see a film of fuel/oil in the manifold.

I'll take a look at the idle control valve.

All the hoses and clamps are pretty tight.

Originally Posted by jumpy chunky View Post
In one of Jake Raby's videos he stresses making sure your coil pack connectors are firmly seated.
Might be worth a double check.
I saw that. Yes, after I installed the new plugs and ignition coils and restarted the vehicle with the same results, I went back to check the connectors. They are all firmly seated.

Originally Posted by Prelude Guy View Post
I was going to suggest unplugging the MAFS. That will help you determine if the MAFS is bad or if the air intake tubes have holes in them.

Then check the Idle Air Control Valve (just had this issue on my BMW 330i)

Then check to see if the alternator might be bad or the belt might have broken.

Then check the coil packs and the connectors.

I hope your timing chain didn't break.
Alternator is good and belt is good. Coilpacks and connectors are good and firmly seated.

I'll follow up regarding the MAF and IAC.

Man, I hope the timing chain didn't break either...

Mike
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Old 06-25-2019, 10:25 PM
  #33  
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I reset the DME/ECU and started the car. It idled poorly for about 30 seconds and disconnecting the MAF made no difference. I could smell un-burned fuel.

Could these symptoms be a sign of an AOS going bad?

Mike
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Old 06-26-2019, 09:13 AM
  #34  
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Not the AOS. Back to a vacuum leak or something else...fuel pressure regulator?
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vacuum lines.pdf (127.6 KB, 9 views)
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Old 06-26-2019, 01:14 PM
  #35  
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^^^^
Thank you for the pictures!

I'm somewhat familiar with the vacuum lines after performing the starter, alternator and the starter/alternator cable replacement a couple years ago. I did have the vacuum lines and rubber replaced about a year ago by a local Porsche repair facility.
As suggested I've taken a look at the vacuum lines...not extensively, however, as I haven't removed any parts yet...but they all look attached and in good condition.

Mike
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Old 06-26-2019, 04:33 PM
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Smoke test it.
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Old 06-26-2019, 07:27 PM
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Originally Posted by 808Bill View Post
Smoke test it.
I'm leaning that way. I have an appointment with Dundon Motorsports for diagnosis and perhaps, repair.

Mike
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Old 06-26-2019, 07:32 PM
  #38  
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Then you're in good hands, best of luck!
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Old 06-26-2019, 08:29 PM
  #39  
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^^^^
I'm fast approaching my limits of skill and means to further diagnose the issues I'm experiencing. I think this is the best option, albeit, more expensive.

Regardless, I'll report back with the diagnosis and results.

Mike
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Old 06-30-2019, 04:38 PM
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With a P0300, P0301, P0302 and a P1316...anyone think that this could be a camshaft solenoid valve causing the issue(s)?

Mike
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Old 06-30-2019, 05:37 PM
  #41  
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Originally Posted by Rdrcr View Post
With a P0300, P0301, P0302 and a P1316...anyone think that this could be a camshaft solenoid valve causing the issue(s)?

Mike
No, I don't.

I know you want a positive diagnosis of the problem before any major steps are taken, but sometimes a failure just doesn't cooperate with the easy normal diagnostic routines. From reading through the posts I think you have an injector spraying/leaking when it is not suppose to..
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Old 06-30-2019, 06:26 PM
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Originally Posted by Porschetech3 View Post
No, I don't.

I know you want a positive diagnosis of the problem before any major steps are taken, but sometimes a failure just doesn't cooperate with the easy normal diagnostic routines. From reading through the posts I think you have an injector spraying/leaking when it is not suppose to..
Thank you for your response. That's interesting...good to know. Several members have suggested injectors.
Yes, I definitely want a positive diagnosis before proceeding to fix the problem.

I do have an appointment for diagnosis/repair but, I don't take the car in for another week, so it's going to continue to bother me until the car is in the shop, lol.

If it is injectors...do you recommend replacing all six?

Mike
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Old 07-01-2019, 01:58 AM
  #43  
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Yes, all 6!
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Old 07-01-2019, 09:55 AM
  #44  
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With 100% new NOT remans. It has beed talked in depth and even though the remans r tested they may not perform the same under load and these cars need good fuel delivery.
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Old 07-01-2019, 11:45 AM
  #45  
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Default Injectors

I'm all for replacing with new. Want to find out if there is a supplier that offers new injectors for less than $78.03 each. That price doesn't include
O-rings.
Appreciate any replies..
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