4.3 Vortec Woes.. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 06-06-2004, 02:01 PM
79454's Avatar
Join Date: Sep 2003
Location: Washington
Posts: 33
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
4.3 Vortec Woes..

I just bought a 93 4.3 Liter Vortec equiped Blazer for my commuter vehicle, and it has some issues. I;m engine savvy, but am not real familiar with these 4.3's, and just wanted to see if anyone has heard of this problem, or has any ideas on a likely cause. THe symptoms are as follows:

Hesitiation - usually as the RPM's rise in first and second gear, it hesitiates and feels like its holding itself back for a few seconds or longer...as it shifts into the next gear, things are smooth again.

I don't notice it as much at freeway speeds, mostly 1st-2nd gear acceleration (makes pulling into fast moving traffic not so fun)..

It does not do it everytime, sometimes is feels perfect, strong and smooth.. i would say that 80% of the time is does its hesitiation.

Black exhaust - the exhaust, especially during startup and warmup is very sooty and charcoal-like. There is not really any black smoke, but a nice black spot of soot on the ground quite quickly.

I don't think there is a blown head-gasket (compression good, oil looks fine). Maybe something EGR or fuel related?? Any help or ideas is appreciated.



Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 06-06-2004, 02:16 PM
coldknock's Avatar
Last photo:
Join Date: Feb 2004
Location: Social Circle, Ga.
Age: 45
Posts: 1,533
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
You should have a check engine light glowing.

Sticky EGR valve is the first thing that pops up in my noggin. If the EGR valve moves freely do an impedance check on the EGR position sensor. Make sure that the idle air control valve is functioning properly too.

If none of these things appear to be the cause then you may want to take it to a qualified tech or the dealership and have them test the ecu for stored trouble codes. If it has none then you likely have a problem with the ecu itself

Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may 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

All times are GMT -6. The time now is 11:36 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.