Go Back   Truck Forums > Chevrolet/GMC Truck Forums > Chevy Silverado/ GMC Sierra Forum
Sign in using an external account
Register Forgot Password?
Search

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 11-14-2011, 08:54 AM
Junior Member
 
Join Date: Nov 2011
Posts: 5
Default Chugging under acceleration. no SES light

heres the deal, i got a 98 GMC sierra with a 5.7 vortec. its starts and idles just fine and as long as you accelerate lightly it is also fine. if i accelerate hard it will just pick up RPM's a little and then sit there and chug and hesitiate. if im at a higher speed and i try to accelerate hard enough to cause a downshift it will not downshift and it will sit there and hessitate and chugg. it up shifts perfectly also. if i stop and put the truck in park or nuetral and i slowly build up RPM i can get it to redline. but if i just hammer on the accelerator in park or nuetral it will get up to about 2500 rpm and sit there and chug and hesitate(same thing it does in drive). there also is no service engine light on. it just randomly started doing this today when i was out for a drive. i turned the truck off and let it sit for 5 hours and then drove it again and it still doing the same thing. Im wondering it anyone has had the same problem and gotten to the bottom of it? or could point me on a good direction to start looking. thanks in advance
This ad is not displayed to registered members.
Register your free account today and become a member on Truckforums!
Reply With Quote
  #2  
Old 11-14-2011, 09:39 AM
NullHead's Avatar
TruckForum Addict
 
Join Date: Apr 2011
Location: Detroit, MI
Posts: 1,034
Default

Use some mas airflow sensor cleaner on your MAF sensor: CRC 05110 Mass Air Flow Sensor Cleaner - 11 Wt oz.

$10 from autozone.
The sensor looks like this:
Click the image to open in full size.

The sensor should be between your airbox and the throttle valve somewhere.

Just take the sensor out, DO NOT TOUCH ANYTHING INSIDE THE SENSOR, lay it on a flat clean work place (I used a plastic lid to a 5 galon bucket) and spray the sensor and let it set. Make sure to follow the instructions on the can carefully, because it's been a while since I've done this

If that doesn't work, the sensor is probably bad.
Reply With Quote
  #3  
Old 11-15-2011, 09:55 PM
Junior Member
 
Join Date: Nov 2011
Posts: 5
Default

so heres what ive done so far. new plugs and wires because i figured i should anyways. that didnt help, the MAF sensor was spotless so i didnt do anything to it yet, but i will clean it tomorrow. i also pulled my front o2 sensors and then ran the truck and it was still the same, so i can check off the cat convertors. im gunna put in a new fuel filter and check MAF and MAP sensors tomorrow and then ill update. thanks for your help
Reply With Quote
  #4  
Old 11-15-2011, 10:18 PM
Mr_Shamrock's Avatar
Chevrolet/GMC, Racing, Recreational Forum Moderator
 
Join Date: Apr 2009
Posts: 2,267
Default

Fuel pressure? I had a 98 Vortec 454 leave me stranded and it was doing a similar thing to what you are describing before it just quit. My fuel filter was blocked bad! The weird thing is I was on a 14 hour trip and it went from running perfect to chugging to dying in a matter of 10 miles or so. I had it towed home and replaced the filter and it fired up and ran great.
__________________
2003 Chevrolet Tahoe 4X4 5.3
2002 Chevrolet 2500HD 4X4 8.1 - BlackBear Tuned

Reply With Quote
  #5  
Old 11-16-2011, 05:25 AM
Razoo's Avatar
Senior Member
 
Join Date: Jun 2011
Location: Central Georgia
Posts: 134
Default

The description of symptoms in the op are classic fuel filter, issues.
__________________
-Frankie

Present stable:
1994 Ford Club Wagon (Chateau) 5.8L (people Mover)
2000 Silverado LS 1500 4.8L Reg. cab, long bed.
2008 GMC Sierra 1500 Crew Cab 5.3L short bed.
2011 dodge Ram Cummins 3500 crew cab dually LWB.
Reply With Quote
  #6  
Old 11-16-2011, 03:56 PM
Junior Member
 
Join Date: Nov 2011
Posts: 5
Default

just put the new fuel filter in and its still doing the same thing. i did a presssure test and i got about 55 when key is on and not running, 48 when running at idle. when you step on it the pressure spikes to 55 maybe 60 and then drops to 48 again........ WTF is this things problem?????
Reply With Quote
  #7  
Old 11-16-2011, 04:46 PM
Mr_Shamrock's Avatar
Chevrolet/GMC, Racing, Recreational Forum Moderator
 
Join Date: Apr 2009
Posts: 2,267
Default

I would start testing sensors - specifically the TPS.
__________________
2003 Chevrolet Tahoe 4X4 5.3
2002 Chevrolet 2500HD 4X4 8.1 - BlackBear Tuned

Reply With Quote
  #8  
Old 11-16-2011, 06:56 PM
NullHead's Avatar
TruckForum Addict
 
Join Date: Apr 2011
Location: Detroit, MI
Posts: 1,034
Default

My money's on the MAF sensor. The Symptoms sound exactly like the problem I had with my mom's van. Apparently microscopic particles build up on the sensor wires, and that's what causes bad readings. Try unplugging the MAF sensor and drive it around. Made a night and day difference for me, but I do acknowledge it could be a different sensor. Just my two cents.
Reply With Quote
  #9  
Old 11-17-2011, 04:06 PM
Junior Member
 
Join Date: Nov 2011
Posts: 5
Default

i put new MAF in and nothing different, tested map and TPS sensors they are good. i call my high school buddy who is a mechanic and he said 48 is too low for these trucks anything below 54 will run funny because they spider injectors need a really PSI to fucntion properly. so new fuel pump is going in in about an hour. ill let you know how it goes.
Reply With Quote
  #10  
Old 11-17-2011, 09:52 PM
Junior Member
 
Join Date: Nov 2011
Posts: 5
Default

it was the fuel pump. i was 48psi before and now i running 54psi and it runs like its brand new
Reply With Quote
Old 11-17-2011, 09:52 PM
 
 
 
Reply



Tags
08, 1998, 2000, accelerating, acceleration, avenger, chevy, chugging, gmc, high, light, manual, ses, sierra, speeds, truck

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Advertising

Featured Sponsors
Vendor Directory

Our Sponsors
Advertising
All times are GMT -5. The time now is 05:49 PM.

Internet Brands, Inc.



SEO by vBSEO ©2010, Crawlability, Inc.