Surging and Stumbling at highway speeds - Chevrolet Forum - Chevy Enthusiasts Forums

Surging and Stumbling at highway speeds


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winkelfish's Avatar
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August 20th, 2010, 6:46 PM   #1  
Surging and Stumbling at highway speeds

I'm the owner of a 2001 Tahoe 5.3 with about 150k on the odometer. I am experiencing a problem with a greater frequency. The problem is a surging and stumbling when at highway speeds (greater than 55). This problem was very infrequent and first occured about 3 years ago and has happened only about five times since. Unfortunately, two of those five times have happened within the last few weeks. The problem happens during trips lasting over an hour and the vehicile is at full operating temperature. Yesterday it was especially bad while driving at about 75 mph the engine begins to surge when on a hill or when accelerating. When I stomp on the gas it gets real bad and seems as though the engine wants to die. Engine will smooth back out at around 50-55 mph. Pulled off freeway after about 10 more miles, let engine idle (just fine), and accelerate hard back on to road. VG power, no surging or stumbling until I get back to those highway speeds. Does not feel like a misfire when it happens, more like too much air or not enough fuel. Just starting with my troubleshooting and any suggestions would be appreciated.

 
in2pro's Avatar
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August 21st, 2010, 2:49 PM   #2  
Welcome to the forum...
I would check the fuel pressure, the pump may be getting weak or the filter/strainer clogged.

 
in2pro's Avatar
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August 21st, 2010, 2:52 PM   #3  
Also check your air filter and intake for any obstructions, leaves, plastic bags, debris, small animals or children....

 
horn5413's Avatar
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August 23rd, 2010, 11:55 AM   #4  
No codes? Can try cleaning the MAF sensor..

 
winkelfish's Avatar
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August 23rd, 2010, 3:11 PM   #5  
Both MAF and air filter clean prior to the last episode and no codes. Checked fuel pressure today, 52-54 psi at ign position and 48-49 with engine running. Changed in line fuel filter and got the same readings. This problem likes to come and go, and usually happens during trips lasting more than an hour. Thanks for your help so far.

 
73shark's Avatar
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August 23rd, 2010, 8:55 PM   #6  
Welcome to the forum.

Has it happened since you changed fuel filter?

 
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