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CEL: Engine stumbling stuttering and wanting to shut-off

 
Old 06-21-2019, 04:01 PM
  #16  
Rdrcr
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Update:

P0300
P0301
P0302
P1316

Mike
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Old 06-21-2019, 11:37 PM
  #17  
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I should have time tomorrow to pull the coils and plugs. Anything else I should be looking at?

Mike
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Old 06-22-2019, 09:11 PM
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I installed the new spark plugs and ignition coils, unfortunately, that didn't solve the rough running and idle issues.

Three of the spark plugs smelled of fuel. #1 spark plug was pretty black and wet. Three of the coils had minor cracks.

Upon restart I can smell fuel.

What are we thinking? Vacuum leak?

Mike
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Old 06-22-2019, 10:13 PM
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So where in WA are you headed,, ?? Just curious...
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Old 06-23-2019, 12:00 AM
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Originally Posted by pdxmotorhead View Post
So where in WA are you headed,, ?? Just curious...
Olympia.

Mike
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Old 06-23-2019, 11:04 AM
  #21  
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Originally Posted by Rdrcr View Post
I installed the new spark plugs and ignition coils, unfortunately, that didn't solve the rough running and idle issues.

Three of the spark plugs smelled of fuel. #1 spark plug was pretty black and wet. Three of the coils had minor cracks.

Upon restart I can smell fuel.

What are we thinking? Vacuum leak?

Mike
Just a wild guess.
Injectors? I would replace them. Bad ones will cause bad things... I'd also wait for someone smarter than me to chime in.
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Old 06-23-2019, 01:54 PM
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^^^^
I'm sure it wouldn't be a bad idea to replace them. However, I don't think the injectors are causing the problem.

I'm gonna dig around under the hood here in a couple hours to see if I can visually identify any potential vacuum leaks.

I'm just not sure what else would cause what I believe to be excess fueling in the cylinders. Just before this incident happened, the car was running flawlessly. I was even getting close to 28mpg on the highway. Crazy!

Mike
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Old 06-24-2019, 05:20 PM
  #23  
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I have a '99' as well.
Our cars are probably in need of injectors. Yours sounds as if the injectors may be leaking at rest and or idle if your plugs are wet. Raw gas isn't benefitial
to spark plugs.
If you have a pressure gauge hook up to test port on fuel rail passenger side and remove vacuum line from regulator. If pressure increases your diaphragm is intact if not your regulator.should be replaced. At idle engine doesn't need as much fuel as it does at higher RPMs.
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Old 06-24-2019, 06:38 PM
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^^^^
Thanks for the suggestion. And, I don't doubt that I may need injectors.

I have a vacuum gauge. However, I can't get the engine to idle. It'll start, stumble and shut off. Any suggestions on being able to perform the test under these conditions?

Mike
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Old 06-25-2019, 11:14 AM
  #25  
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QUOTE=Rdrcr;15930057]^^^^
Thanks for the suggestion. And, I don't doubt that I may need injectors.

I have a vacuum gauge. However, I can't get the engine to idle. It'll start, stumble and shut off. Any suggestions on being able to perform the test under these conditions?

Mike[/QUOTE]

Your injectors are 20 years old...Don't doubt them possibly needing replacement. JR spoke in depth about them causing issues as they've aged.
Air filter clean?
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Old 06-25-2019, 12:01 PM
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^^^^
Air filter is clean.

Trust me, I don't have any issues with replacing 20 year old injectors.
However, I don't want to throw parts at the car attempting to diagnose a problem. I want to positively identify the problem, resolve it, and move forward with additional preventative maintenance.

Mike
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Old 06-25-2019, 12:27 PM
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Originally Posted by Rdrcr View Post
^^^^
Air filter is clean.

Trust me, I don't have any issues with replacing 20 year old injectors.
However, I don't want to throw parts at the car attempting to diagnose a problem. I want to positively identify the problem, resolve it, and move forward with additional preventative maintenance.

Mike
I totally get that. Good luck!
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Old 06-25-2019, 01:14 PM
  #28  
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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.
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Old 06-25-2019, 01:41 PM
  #29  
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In one of Jake Raby's videos he stresses making sure your coil pack connectors are firmly seated.
Might be worth a double check.
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Old 06-25-2019, 02:47 PM
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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.
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