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RUNNING ROUGH/IDLING FUNNY

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Old 03-12-2007, 01:46 AM
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Default RUNNING ROUGH/IDLING FUNNY

Hi everybody!

I have a problem with my 1995 LT Blazer 4x4 with a 4.3L V6. It has 157,000 miles on it. After driving 245 miles in one day, all highway, it started to idle rough. I instantly thought it was plug wires, because i have had this problem before. So i let it sit for about 2hrs before i started it up again. It still idled rough. So i drove it about 1/4 mile before stopping and parking it for the night. I could smell a strong gas smell, and the exhaust smell was very noticable also. I turned it off for a min, then started it up again, this time it idled high, 1400rpm. I revved it a little, let it idle back down, still at 1400rpm. After i shut it off, i saw that the tach did not go back down to 0, it stayed at 1400rpm. So i let it sit for a min or so, then i started it up and it idled just fine. So as of right now its idling normal but still has a stong gas smell. Earlier today i replaced the battery terminal connector because of heavy corrision on it. My battery carried a low charge so i thought it would be good to replace the connector. Can anybody help me?!?! I dont know what to do...

Thanks
 
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Old 03-12-2007, 05:33 AM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Go to a Autozone or any parts store n get a free scan..see if its throwing a code.Be the easy way
 
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Old 03-12-2007, 09:26 AM
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Default RE: RUNNING ROUGH/IDLING FUNNY

I'd get a fuel pressure gauge and see what your leak down is like. I'd also recommend that you pop off the plenum cover and inspect for leaks around the CPI spider.
 
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Old 03-12-2007, 11:29 AM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Yah I'll go to Advanced Auto today and get a scan done, I'll post my results once i get the scan done. Thanks
 
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Old 03-12-2007, 06:57 PM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Ok so i went to Advanced Auto, O'Reilly, and Auto Zone and all 3 couldnt do anything because they said if the check engine light is not on...it wont read the code...so now im stuck...and today the transmission started to act up. when i come up to a stop and i get on the brakes hard, the thing lurches foward. im not sure what is going on with that so if anybody knows...please let me know.

thanks
 
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Old 03-13-2007, 04:50 PM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Possibly a bad tank of gas. Bad battery terminal connection.Check all your vacuum lines for one off or dry & cracked and most important......................
LEAVE YOUR SPIDER INJECTOR ALONE.
Do not even mention it (spider injector) to a garage or you will be shelling out big money for nothing! It does not just go bad one day as everybody seems to think on this forum.
The gas smell is just un-burnt fuel from your truck idling poorly.
 
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Old 03-13-2007, 05:27 PM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Geez... Here we go again with this... Man give it a rest.

The only way you can tell if the CPI spider is leaking is to remove the upper plenum and visually check for leaks. Ofcourse, a fuel pressure leak down test should be performed prior to opening up the plenum to see if there is actually a pressure bleed on the system. If you have pooling fuel in the lower intake manifold recesses, then you have a leaky CPI spider.

And yes, the FPR does JUST go bad. This is a very well documented problem with the CPI motors.
 
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Old 03-13-2007, 06:09 PM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Alright thanks for all the help...ill check all the vacuum hoses and do a fuel pressure leak down test when i can...ill post again once i do the tests...

oh by the way...how much does a fuel pressure tester cost? or would a shop be cheaper?

thanks
 
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Old 03-13-2007, 06:26 PM
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Default RE: RUNNING ROUGH/IDLING FUNNY

Most large chain autoparts stores will rent a fuel pressure gauge. You can purchase them for roughly $30 for a cheaper model and up from there depending on what you want to get out of it. I have a cheap model that I have had for 5 or so years.
 
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Old 03-18-2007, 10:06 PM
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Default RE: RUNNING ROUGH/IDLING FUNNY

OK so i got it scanned at Advanced and the computer said nothing was wrong...so for now im just gonna leave it alone. i might be changing the EGR valve in the near because i believe i am loosing vacuum pressure.

thanks for all your help
 


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